runtime: add new command to collect metrics from Kata containers

Add a new command to collect metrics and return metrics to Prometheus.

Signed-off-by: bin liu <bin@hyper.sh>
This commit is contained in:
bin liu
2020-06-10 17:40:47 +08:00
parent 186fed2a11
commit 1b75daa00f
280 changed files with 68037 additions and 96 deletions

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package digestset
import (
"errors"
"sort"
"strings"
"sync"
digest "github.com/opencontainers/go-digest"
)
var (
// ErrDigestNotFound is used when a matching digest
// could not be found in a set.
ErrDigestNotFound = errors.New("digest not found")
// ErrDigestAmbiguous is used when multiple digests
// are found in a set. None of the matching digests
// should be considered valid matches.
ErrDigestAmbiguous = errors.New("ambiguous digest string")
)
// Set is used to hold a unique set of digests which
// may be easily referenced by easily referenced by a string
// representation of the digest as well as short representation.
// The uniqueness of the short representation is based on other
// digests in the set. If digests are omitted from this set,
// collisions in a larger set may not be detected, therefore it
// is important to always do short representation lookups on
// the complete set of digests. To mitigate collisions, an
// appropriately long short code should be used.
type Set struct {
mutex sync.RWMutex
entries digestEntries
}
// NewSet creates an empty set of digests
// which may have digests added.
func NewSet() *Set {
return &Set{
entries: digestEntries{},
}
}
// checkShortMatch checks whether two digests match as either whole
// values or short values. This function does not test equality,
// rather whether the second value could match against the first
// value.
func checkShortMatch(alg digest.Algorithm, hex, shortAlg, shortHex string) bool {
if len(hex) == len(shortHex) {
if hex != shortHex {
return false
}
if len(shortAlg) > 0 && string(alg) != shortAlg {
return false
}
} else if !strings.HasPrefix(hex, shortHex) {
return false
} else if len(shortAlg) > 0 && string(alg) != shortAlg {
return false
}
return true
}
// Lookup looks for a digest matching the given string representation.
// If no digests could be found ErrDigestNotFound will be returned
// with an empty digest value. If multiple matches are found
// ErrDigestAmbiguous will be returned with an empty digest value.
func (dst *Set) Lookup(d string) (digest.Digest, error) {
dst.mutex.RLock()
defer dst.mutex.RUnlock()
if len(dst.entries) == 0 {
return "", ErrDigestNotFound
}
var (
searchFunc func(int) bool
alg digest.Algorithm
hex string
)
dgst, err := digest.Parse(d)
if err == digest.ErrDigestInvalidFormat {
hex = d
searchFunc = func(i int) bool {
return dst.entries[i].val >= d
}
} else {
hex = dgst.Hex()
alg = dgst.Algorithm()
searchFunc = func(i int) bool {
if dst.entries[i].val == hex {
return dst.entries[i].alg >= alg
}
return dst.entries[i].val >= hex
}
}
idx := sort.Search(len(dst.entries), searchFunc)
if idx == len(dst.entries) || !checkShortMatch(dst.entries[idx].alg, dst.entries[idx].val, string(alg), hex) {
return "", ErrDigestNotFound
}
if dst.entries[idx].alg == alg && dst.entries[idx].val == hex {
return dst.entries[idx].digest, nil
}
if idx+1 < len(dst.entries) && checkShortMatch(dst.entries[idx+1].alg, dst.entries[idx+1].val, string(alg), hex) {
return "", ErrDigestAmbiguous
}
return dst.entries[idx].digest, nil
}
// Add adds the given digest to the set. An error will be returned
// if the given digest is invalid. If the digest already exists in the
// set, this operation will be a no-op.
func (dst *Set) Add(d digest.Digest) error {
if err := d.Validate(); err != nil {
return err
}
dst.mutex.Lock()
defer dst.mutex.Unlock()
entry := &digestEntry{alg: d.Algorithm(), val: d.Hex(), digest: d}
searchFunc := func(i int) bool {
if dst.entries[i].val == entry.val {
return dst.entries[i].alg >= entry.alg
}
return dst.entries[i].val >= entry.val
}
idx := sort.Search(len(dst.entries), searchFunc)
if idx == len(dst.entries) {
dst.entries = append(dst.entries, entry)
return nil
} else if dst.entries[idx].digest == d {
return nil
}
entries := append(dst.entries, nil)
copy(entries[idx+1:], entries[idx:len(entries)-1])
entries[idx] = entry
dst.entries = entries
return nil
}
// Remove removes the given digest from the set. An err will be
// returned if the given digest is invalid. If the digest does
// not exist in the set, this operation will be a no-op.
func (dst *Set) Remove(d digest.Digest) error {
if err := d.Validate(); err != nil {
return err
}
dst.mutex.Lock()
defer dst.mutex.Unlock()
entry := &digestEntry{alg: d.Algorithm(), val: d.Hex(), digest: d}
searchFunc := func(i int) bool {
if dst.entries[i].val == entry.val {
return dst.entries[i].alg >= entry.alg
}
return dst.entries[i].val >= entry.val
}
idx := sort.Search(len(dst.entries), searchFunc)
// Not found if idx is after or value at idx is not digest
if idx == len(dst.entries) || dst.entries[idx].digest != d {
return nil
}
entries := dst.entries
copy(entries[idx:], entries[idx+1:])
entries = entries[:len(entries)-1]
dst.entries = entries
return nil
}
// All returns all the digests in the set
func (dst *Set) All() []digest.Digest {
dst.mutex.RLock()
defer dst.mutex.RUnlock()
retValues := make([]digest.Digest, len(dst.entries))
for i := range dst.entries {
retValues[i] = dst.entries[i].digest
}
return retValues
}
// ShortCodeTable returns a map of Digest to unique short codes. The
// length represents the minimum value, the maximum length may be the
// entire value of digest if uniqueness cannot be achieved without the
// full value. This function will attempt to make short codes as short
// as possible to be unique.
func ShortCodeTable(dst *Set, length int) map[digest.Digest]string {
dst.mutex.RLock()
defer dst.mutex.RUnlock()
m := make(map[digest.Digest]string, len(dst.entries))
l := length
resetIdx := 0
for i := 0; i < len(dst.entries); i++ {
var short string
extended := true
for extended {
extended = false
if len(dst.entries[i].val) <= l {
short = dst.entries[i].digest.String()
} else {
short = dst.entries[i].val[:l]
for j := i + 1; j < len(dst.entries); j++ {
if checkShortMatch(dst.entries[j].alg, dst.entries[j].val, "", short) {
if j > resetIdx {
resetIdx = j
}
extended = true
} else {
break
}
}
if extended {
l++
}
}
}
m[dst.entries[i].digest] = short
if i >= resetIdx {
l = length
}
}
return m
}
type digestEntry struct {
alg digest.Algorithm
val string
digest digest.Digest
}
type digestEntries []*digestEntry
func (d digestEntries) Len() int {
return len(d)
}
func (d digestEntries) Less(i, j int) bool {
if d[i].val != d[j].val {
return d[i].val < d[j].val
}
return d[i].alg < d[j].alg
}
func (d digestEntries) Swap(i, j int) {
d[i], d[j] = d[j], d[i]
}

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package reference
import "path"
// IsNameOnly returns true if reference only contains a repo name.
func IsNameOnly(ref Named) bool {
if _, ok := ref.(NamedTagged); ok {
return false
}
if _, ok := ref.(Canonical); ok {
return false
}
return true
}
// FamiliarName returns the familiar name string
// for the given named, familiarizing if needed.
func FamiliarName(ref Named) string {
if nn, ok := ref.(normalizedNamed); ok {
return nn.Familiar().Name()
}
return ref.Name()
}
// FamiliarString returns the familiar string representation
// for the given reference, familiarizing if needed.
func FamiliarString(ref Reference) string {
if nn, ok := ref.(normalizedNamed); ok {
return nn.Familiar().String()
}
return ref.String()
}
// FamiliarMatch reports whether ref matches the specified pattern.
// See https://godoc.org/path#Match for supported patterns.
func FamiliarMatch(pattern string, ref Reference) (bool, error) {
matched, err := path.Match(pattern, FamiliarString(ref))
if namedRef, isNamed := ref.(Named); isNamed && !matched {
matched, _ = path.Match(pattern, FamiliarName(namedRef))
}
return matched, err
}

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package reference
import (
"errors"
"fmt"
"strings"
"github.com/docker/distribution/digestset"
"github.com/opencontainers/go-digest"
)
var (
legacyDefaultDomain = "index.docker.io"
defaultDomain = "docker.io"
officialRepoName = "library"
defaultTag = "latest"
)
// normalizedNamed represents a name which has been
// normalized and has a familiar form. A familiar name
// is what is used in Docker UI. An example normalized
// name is "docker.io/library/ubuntu" and corresponding
// familiar name of "ubuntu".
type normalizedNamed interface {
Named
Familiar() Named
}
// ParseNormalizedNamed parses a string into a named reference
// transforming a familiar name from Docker UI to a fully
// qualified reference. If the value may be an identifier
// use ParseAnyReference.
func ParseNormalizedNamed(s string) (Named, error) {
if ok := anchoredIdentifierRegexp.MatchString(s); ok {
return nil, fmt.Errorf("invalid repository name (%s), cannot specify 64-byte hexadecimal strings", s)
}
domain, remainder := splitDockerDomain(s)
var remoteName string
if tagSep := strings.IndexRune(remainder, ':'); tagSep > -1 {
remoteName = remainder[:tagSep]
} else {
remoteName = remainder
}
if strings.ToLower(remoteName) != remoteName {
return nil, errors.New("invalid reference format: repository name must be lowercase")
}
ref, err := Parse(domain + "/" + remainder)
if err != nil {
return nil, err
}
named, isNamed := ref.(Named)
if !isNamed {
return nil, fmt.Errorf("reference %s has no name", ref.String())
}
return named, nil
}
// splitDockerDomain splits a repository name to domain and remotename string.
// If no valid domain is found, the default domain is used. Repository name
// needs to be already validated before.
func splitDockerDomain(name string) (domain, remainder string) {
i := strings.IndexRune(name, '/')
if i == -1 || (!strings.ContainsAny(name[:i], ".:") && name[:i] != "localhost") {
domain, remainder = defaultDomain, name
} else {
domain, remainder = name[:i], name[i+1:]
}
if domain == legacyDefaultDomain {
domain = defaultDomain
}
if domain == defaultDomain && !strings.ContainsRune(remainder, '/') {
remainder = officialRepoName + "/" + remainder
}
return
}
// familiarizeName returns a shortened version of the name familiar
// to to the Docker UI. Familiar names have the default domain
// "docker.io" and "library/" repository prefix removed.
// For example, "docker.io/library/redis" will have the familiar
// name "redis" and "docker.io/dmcgowan/myapp" will be "dmcgowan/myapp".
// Returns a familiarized named only reference.
func familiarizeName(named namedRepository) repository {
repo := repository{
domain: named.Domain(),
path: named.Path(),
}
if repo.domain == defaultDomain {
repo.domain = ""
// Handle official repositories which have the pattern "library/<official repo name>"
if split := strings.Split(repo.path, "/"); len(split) == 2 && split[0] == officialRepoName {
repo.path = split[1]
}
}
return repo
}
func (r reference) Familiar() Named {
return reference{
namedRepository: familiarizeName(r.namedRepository),
tag: r.tag,
digest: r.digest,
}
}
func (r repository) Familiar() Named {
return familiarizeName(r)
}
func (t taggedReference) Familiar() Named {
return taggedReference{
namedRepository: familiarizeName(t.namedRepository),
tag: t.tag,
}
}
func (c canonicalReference) Familiar() Named {
return canonicalReference{
namedRepository: familiarizeName(c.namedRepository),
digest: c.digest,
}
}
// TagNameOnly adds the default tag "latest" to a reference if it only has
// a repo name.
func TagNameOnly(ref Named) Named {
if IsNameOnly(ref) {
namedTagged, err := WithTag(ref, defaultTag)
if err != nil {
// Default tag must be valid, to create a NamedTagged
// type with non-validated input the WithTag function
// should be used instead
panic(err)
}
return namedTagged
}
return ref
}
// ParseAnyReference parses a reference string as a possible identifier,
// full digest, or familiar name.
func ParseAnyReference(ref string) (Reference, error) {
if ok := anchoredIdentifierRegexp.MatchString(ref); ok {
return digestReference("sha256:" + ref), nil
}
if dgst, err := digest.Parse(ref); err == nil {
return digestReference(dgst), nil
}
return ParseNormalizedNamed(ref)
}
// ParseAnyReferenceWithSet parses a reference string as a possible short
// identifier to be matched in a digest set, a full digest, or familiar name.
func ParseAnyReferenceWithSet(ref string, ds *digestset.Set) (Reference, error) {
if ok := anchoredShortIdentifierRegexp.MatchString(ref); ok {
dgst, err := ds.Lookup(ref)
if err == nil {
return digestReference(dgst), nil
}
} else {
if dgst, err := digest.Parse(ref); err == nil {
return digestReference(dgst), nil
}
}
return ParseNormalizedNamed(ref)
}

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// Package reference provides a general type to represent any way of referencing images within the registry.
// Its main purpose is to abstract tags and digests (content-addressable hash).
//
// Grammar
//
// reference := name [ ":" tag ] [ "@" digest ]
// name := [domain '/'] path-component ['/' path-component]*
// domain := domain-component ['.' domain-component]* [':' port-number]
// domain-component := /([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])/
// port-number := /[0-9]+/
// path-component := alpha-numeric [separator alpha-numeric]*
// alpha-numeric := /[a-z0-9]+/
// separator := /[_.]|__|[-]*/
//
// tag := /[\w][\w.-]{0,127}/
//
// digest := digest-algorithm ":" digest-hex
// digest-algorithm := digest-algorithm-component [ digest-algorithm-separator digest-algorithm-component ]*
// digest-algorithm-separator := /[+.-_]/
// digest-algorithm-component := /[A-Za-z][A-Za-z0-9]*/
// digest-hex := /[0-9a-fA-F]{32,}/ ; At least 128 bit digest value
//
// identifier := /[a-f0-9]{64}/
// short-identifier := /[a-f0-9]{6,64}/
package reference
import (
"errors"
"fmt"
"strings"
"github.com/opencontainers/go-digest"
)
const (
// NameTotalLengthMax is the maximum total number of characters in a repository name.
NameTotalLengthMax = 255
)
var (
// ErrReferenceInvalidFormat represents an error while trying to parse a string as a reference.
ErrReferenceInvalidFormat = errors.New("invalid reference format")
// ErrTagInvalidFormat represents an error while trying to parse a string as a tag.
ErrTagInvalidFormat = errors.New("invalid tag format")
// ErrDigestInvalidFormat represents an error while trying to parse a string as a tag.
ErrDigestInvalidFormat = errors.New("invalid digest format")
// ErrNameContainsUppercase is returned for invalid repository names that contain uppercase characters.
ErrNameContainsUppercase = errors.New("repository name must be lowercase")
// ErrNameEmpty is returned for empty, invalid repository names.
ErrNameEmpty = errors.New("repository name must have at least one component")
// ErrNameTooLong is returned when a repository name is longer than NameTotalLengthMax.
ErrNameTooLong = fmt.Errorf("repository name must not be more than %v characters", NameTotalLengthMax)
// ErrNameNotCanonical is returned when a name is not canonical.
ErrNameNotCanonical = errors.New("repository name must be canonical")
)
// Reference is an opaque object reference identifier that may include
// modifiers such as a hostname, name, tag, and digest.
type Reference interface {
// String returns the full reference
String() string
}
// Field provides a wrapper type for resolving correct reference types when
// working with encoding.
type Field struct {
reference Reference
}
// AsField wraps a reference in a Field for encoding.
func AsField(reference Reference) Field {
return Field{reference}
}
// Reference unwraps the reference type from the field to
// return the Reference object. This object should be
// of the appropriate type to further check for different
// reference types.
func (f Field) Reference() Reference {
return f.reference
}
// MarshalText serializes the field to byte text which
// is the string of the reference.
func (f Field) MarshalText() (p []byte, err error) {
return []byte(f.reference.String()), nil
}
// UnmarshalText parses text bytes by invoking the
// reference parser to ensure the appropriately
// typed reference object is wrapped by field.
func (f *Field) UnmarshalText(p []byte) error {
r, err := Parse(string(p))
if err != nil {
return err
}
f.reference = r
return nil
}
// Named is an object with a full name
type Named interface {
Reference
Name() string
}
// Tagged is an object which has a tag
type Tagged interface {
Reference
Tag() string
}
// NamedTagged is an object including a name and tag.
type NamedTagged interface {
Named
Tag() string
}
// Digested is an object which has a digest
// in which it can be referenced by
type Digested interface {
Reference
Digest() digest.Digest
}
// Canonical reference is an object with a fully unique
// name including a name with domain and digest
type Canonical interface {
Named
Digest() digest.Digest
}
// namedRepository is a reference to a repository with a name.
// A namedRepository has both domain and path components.
type namedRepository interface {
Named
Domain() string
Path() string
}
// Domain returns the domain part of the Named reference
func Domain(named Named) string {
if r, ok := named.(namedRepository); ok {
return r.Domain()
}
domain, _ := splitDomain(named.Name())
return domain
}
// Path returns the name without the domain part of the Named reference
func Path(named Named) (name string) {
if r, ok := named.(namedRepository); ok {
return r.Path()
}
_, path := splitDomain(named.Name())
return path
}
func splitDomain(name string) (string, string) {
match := anchoredNameRegexp.FindStringSubmatch(name)
if len(match) != 3 {
return "", name
}
return match[1], match[2]
}
// SplitHostname splits a named reference into a
// hostname and name string. If no valid hostname is
// found, the hostname is empty and the full value
// is returned as name
// DEPRECATED: Use Domain or Path
func SplitHostname(named Named) (string, string) {
if r, ok := named.(namedRepository); ok {
return r.Domain(), r.Path()
}
return splitDomain(named.Name())
}
// Parse parses s and returns a syntactically valid Reference.
// If an error was encountered it is returned, along with a nil Reference.
// NOTE: Parse will not handle short digests.
func Parse(s string) (Reference, error) {
matches := ReferenceRegexp.FindStringSubmatch(s)
if matches == nil {
if s == "" {
return nil, ErrNameEmpty
}
if ReferenceRegexp.FindStringSubmatch(strings.ToLower(s)) != nil {
return nil, ErrNameContainsUppercase
}
return nil, ErrReferenceInvalidFormat
}
if len(matches[1]) > NameTotalLengthMax {
return nil, ErrNameTooLong
}
var repo repository
nameMatch := anchoredNameRegexp.FindStringSubmatch(matches[1])
if nameMatch != nil && len(nameMatch) == 3 {
repo.domain = nameMatch[1]
repo.path = nameMatch[2]
} else {
repo.domain = ""
repo.path = matches[1]
}
ref := reference{
namedRepository: repo,
tag: matches[2],
}
if matches[3] != "" {
var err error
ref.digest, err = digest.Parse(matches[3])
if err != nil {
return nil, err
}
}
r := getBestReferenceType(ref)
if r == nil {
return nil, ErrNameEmpty
}
return r, nil
}
// ParseNamed parses s and returns a syntactically valid reference implementing
// the Named interface. The reference must have a name and be in the canonical
// form, otherwise an error is returned.
// If an error was encountered it is returned, along with a nil Reference.
// NOTE: ParseNamed will not handle short digests.
func ParseNamed(s string) (Named, error) {
named, err := ParseNormalizedNamed(s)
if err != nil {
return nil, err
}
if named.String() != s {
return nil, ErrNameNotCanonical
}
return named, nil
}
// WithName returns a named object representing the given string. If the input
// is invalid ErrReferenceInvalidFormat will be returned.
func WithName(name string) (Named, error) {
if len(name) > NameTotalLengthMax {
return nil, ErrNameTooLong
}
match := anchoredNameRegexp.FindStringSubmatch(name)
if match == nil || len(match) != 3 {
return nil, ErrReferenceInvalidFormat
}
return repository{
domain: match[1],
path: match[2],
}, nil
}
// WithTag combines the name from "name" and the tag from "tag" to form a
// reference incorporating both the name and the tag.
func WithTag(name Named, tag string) (NamedTagged, error) {
if !anchoredTagRegexp.MatchString(tag) {
return nil, ErrTagInvalidFormat
}
var repo repository
if r, ok := name.(namedRepository); ok {
repo.domain = r.Domain()
repo.path = r.Path()
} else {
repo.path = name.Name()
}
if canonical, ok := name.(Canonical); ok {
return reference{
namedRepository: repo,
tag: tag,
digest: canonical.Digest(),
}, nil
}
return taggedReference{
namedRepository: repo,
tag: tag,
}, nil
}
// WithDigest combines the name from "name" and the digest from "digest" to form
// a reference incorporating both the name and the digest.
func WithDigest(name Named, digest digest.Digest) (Canonical, error) {
if !anchoredDigestRegexp.MatchString(digest.String()) {
return nil, ErrDigestInvalidFormat
}
var repo repository
if r, ok := name.(namedRepository); ok {
repo.domain = r.Domain()
repo.path = r.Path()
} else {
repo.path = name.Name()
}
if tagged, ok := name.(Tagged); ok {
return reference{
namedRepository: repo,
tag: tagged.Tag(),
digest: digest,
}, nil
}
return canonicalReference{
namedRepository: repo,
digest: digest,
}, nil
}
// TrimNamed removes any tag or digest from the named reference.
func TrimNamed(ref Named) Named {
domain, path := SplitHostname(ref)
return repository{
domain: domain,
path: path,
}
}
func getBestReferenceType(ref reference) Reference {
if ref.Name() == "" {
// Allow digest only references
if ref.digest != "" {
return digestReference(ref.digest)
}
return nil
}
if ref.tag == "" {
if ref.digest != "" {
return canonicalReference{
namedRepository: ref.namedRepository,
digest: ref.digest,
}
}
return ref.namedRepository
}
if ref.digest == "" {
return taggedReference{
namedRepository: ref.namedRepository,
tag: ref.tag,
}
}
return ref
}
type reference struct {
namedRepository
tag string
digest digest.Digest
}
func (r reference) String() string {
return r.Name() + ":" + r.tag + "@" + r.digest.String()
}
func (r reference) Tag() string {
return r.tag
}
func (r reference) Digest() digest.Digest {
return r.digest
}
type repository struct {
domain string
path string
}
func (r repository) String() string {
return r.Name()
}
func (r repository) Name() string {
if r.domain == "" {
return r.path
}
return r.domain + "/" + r.path
}
func (r repository) Domain() string {
return r.domain
}
func (r repository) Path() string {
return r.path
}
type digestReference digest.Digest
func (d digestReference) String() string {
return digest.Digest(d).String()
}
func (d digestReference) Digest() digest.Digest {
return digest.Digest(d)
}
type taggedReference struct {
namedRepository
tag string
}
func (t taggedReference) String() string {
return t.Name() + ":" + t.tag
}
func (t taggedReference) Tag() string {
return t.tag
}
type canonicalReference struct {
namedRepository
digest digest.Digest
}
func (c canonicalReference) String() string {
return c.Name() + "@" + c.digest.String()
}
func (c canonicalReference) Digest() digest.Digest {
return c.digest
}

View File

@@ -0,0 +1,143 @@
package reference
import "regexp"
var (
// alphaNumericRegexp defines the alpha numeric atom, typically a
// component of names. This only allows lower case characters and digits.
alphaNumericRegexp = match(`[a-z0-9]+`)
// separatorRegexp defines the separators allowed to be embedded in name
// components. This allow one period, one or two underscore and multiple
// dashes.
separatorRegexp = match(`(?:[._]|__|[-]*)`)
// nameComponentRegexp restricts registry path component names to start
// with at least one letter or number, with following parts able to be
// separated by one period, one or two underscore and multiple dashes.
nameComponentRegexp = expression(
alphaNumericRegexp,
optional(repeated(separatorRegexp, alphaNumericRegexp)))
// domainComponentRegexp restricts the registry domain component of a
// repository name to start with a component as defined by DomainRegexp
// and followed by an optional port.
domainComponentRegexp = match(`(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])`)
// DomainRegexp defines the structure of potential domain components
// that may be part of image names. This is purposely a subset of what is
// allowed by DNS to ensure backwards compatibility with Docker image
// names.
DomainRegexp = expression(
domainComponentRegexp,
optional(repeated(literal(`.`), domainComponentRegexp)),
optional(literal(`:`), match(`[0-9]+`)))
// TagRegexp matches valid tag names. From docker/docker:graph/tags.go.
TagRegexp = match(`[\w][\w.-]{0,127}`)
// anchoredTagRegexp matches valid tag names, anchored at the start and
// end of the matched string.
anchoredTagRegexp = anchored(TagRegexp)
// DigestRegexp matches valid digests.
DigestRegexp = match(`[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,}`)
// anchoredDigestRegexp matches valid digests, anchored at the start and
// end of the matched string.
anchoredDigestRegexp = anchored(DigestRegexp)
// NameRegexp is the format for the name component of references. The
// regexp has capturing groups for the domain and name part omitting
// the separating forward slash from either.
NameRegexp = expression(
optional(DomainRegexp, literal(`/`)),
nameComponentRegexp,
optional(repeated(literal(`/`), nameComponentRegexp)))
// anchoredNameRegexp is used to parse a name value, capturing the
// domain and trailing components.
anchoredNameRegexp = anchored(
optional(capture(DomainRegexp), literal(`/`)),
capture(nameComponentRegexp,
optional(repeated(literal(`/`), nameComponentRegexp))))
// ReferenceRegexp is the full supported format of a reference. The regexp
// is anchored and has capturing groups for name, tag, and digest
// components.
ReferenceRegexp = anchored(capture(NameRegexp),
optional(literal(":"), capture(TagRegexp)),
optional(literal("@"), capture(DigestRegexp)))
// IdentifierRegexp is the format for string identifier used as a
// content addressable identifier using sha256. These identifiers
// are like digests without the algorithm, since sha256 is used.
IdentifierRegexp = match(`([a-f0-9]{64})`)
// ShortIdentifierRegexp is the format used to represent a prefix
// of an identifier. A prefix may be used to match a sha256 identifier
// within a list of trusted identifiers.
ShortIdentifierRegexp = match(`([a-f0-9]{6,64})`)
// anchoredIdentifierRegexp is used to check or match an
// identifier value, anchored at start and end of string.
anchoredIdentifierRegexp = anchored(IdentifierRegexp)
// anchoredShortIdentifierRegexp is used to check if a value
// is a possible identifier prefix, anchored at start and end
// of string.
anchoredShortIdentifierRegexp = anchored(ShortIdentifierRegexp)
)
// match compiles the string to a regular expression.
var match = regexp.MustCompile
// literal compiles s into a literal regular expression, escaping any regexp
// reserved characters.
func literal(s string) *regexp.Regexp {
re := match(regexp.QuoteMeta(s))
if _, complete := re.LiteralPrefix(); !complete {
panic("must be a literal")
}
return re
}
// expression defines a full expression, where each regular expression must
// follow the previous.
func expression(res ...*regexp.Regexp) *regexp.Regexp {
var s string
for _, re := range res {
s += re.String()
}
return match(s)
}
// optional wraps the expression in a non-capturing group and makes the
// production optional.
func optional(res ...*regexp.Regexp) *regexp.Regexp {
return match(group(expression(res...)).String() + `?`)
}
// repeated wraps the regexp in a non-capturing group to get one or more
// matches.
func repeated(res ...*regexp.Regexp) *regexp.Regexp {
return match(group(expression(res...)).String() + `+`)
}
// group wraps the regexp in a non-capturing group.
func group(res ...*regexp.Regexp) *regexp.Regexp {
return match(`(?:` + expression(res...).String() + `)`)
}
// capture wraps the expression in a capturing group.
func capture(res ...*regexp.Regexp) *regexp.Regexp {
return match(`(` + expression(res...).String() + `)`)
}
// anchored anchors the regular expression by adding start and end delimiters.
func anchored(res ...*regexp.Regexp) *regexp.Regexp {
return match(`^` + expression(res...).String() + `$`)
}

1652
src/runtime/vendor/github.com/docker/docker/AUTHORS generated vendored Normal file

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191
src/runtime/vendor/github.com/docker/docker/LICENSE generated vendored Normal file
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Apache License
Version 2.0, January 2004
https://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
Copyright 2013-2016 Docker, Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
https://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

19
src/runtime/vendor/github.com/docker/docker/NOTICE generated vendored Normal file
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Docker
Copyright 2012-2016 Docker, Inc.
This product includes software developed at Docker, Inc. (https://www.docker.com).
This product contains software (https://github.com/kr/pty) developed
by Keith Rarick, licensed under the MIT License.
The following is courtesy of our legal counsel:
Use and transfer of Docker may be subject to certain restrictions by the
United States and other governments.
It is your responsibility to ensure that your use and/or transfer does not
violate applicable laws.
For more information, please see https://www.bis.doc.gov
See also https://www.apache.org/dev/crypto.html and/or seek legal counsel.

View File

@@ -0,0 +1,71 @@
package random
import (
cryptorand "crypto/rand"
"io"
"math"
"math/big"
"math/rand"
"sync"
"time"
)
// Rand is a global *rand.Rand instance, which initialized with NewSource() source.
var Rand = rand.New(NewSource())
// Reader is a global, shared instance of a pseudorandom bytes generator.
// It doesn't consume entropy.
var Reader io.Reader = &reader{rnd: Rand}
// copypaste from standard math/rand
type lockedSource struct {
lk sync.Mutex
src rand.Source
}
func (r *lockedSource) Int63() (n int64) {
r.lk.Lock()
n = r.src.Int63()
r.lk.Unlock()
return
}
func (r *lockedSource) Seed(seed int64) {
r.lk.Lock()
r.src.Seed(seed)
r.lk.Unlock()
}
// NewSource returns math/rand.Source safe for concurrent use and initialized
// with current unix-nano timestamp
func NewSource() rand.Source {
var seed int64
if cryptoseed, err := cryptorand.Int(cryptorand.Reader, big.NewInt(math.MaxInt64)); err != nil {
// This should not happen, but worst-case fallback to time-based seed.
seed = time.Now().UnixNano()
} else {
seed = cryptoseed.Int64()
}
return &lockedSource{
src: rand.NewSource(seed),
}
}
type reader struct {
rnd *rand.Rand
}
func (r *reader) Read(b []byte) (int, error) {
i := 0
for {
val := r.rnd.Int63()
for val > 0 {
b[i] = byte(val)
i++
if i == len(b) {
return i, nil
}
val >>= 8
}
}
}

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@@ -0,0 +1 @@
This package provides helper functions for dealing with string identifiers

View File

@@ -0,0 +1,69 @@
// Package stringid provides helper functions for dealing with string identifiers
package stringid
import (
"crypto/rand"
"encoding/hex"
"io"
"regexp"
"strconv"
"strings"
"github.com/docker/docker/pkg/random"
)
const shortLen = 12
var validShortID = regexp.MustCompile("^[a-z0-9]{12}$")
// IsShortID determines if an arbitrary string *looks like* a short ID.
func IsShortID(id string) bool {
return validShortID.MatchString(id)
}
// TruncateID returns a shorthand version of a string identifier for convenience.
// A collision with other shorthands is very unlikely, but possible.
// In case of a collision a lookup with TruncIndex.Get() will fail, and the caller
// will need to use a longer prefix, or the full-length Id.
func TruncateID(id string) string {
if i := strings.IndexRune(id, ':'); i >= 0 {
id = id[i+1:]
}
if len(id) > shortLen {
id = id[:shortLen]
}
return id
}
func generateID(crypto bool) string {
b := make([]byte, 32)
r := random.Reader
if crypto {
r = rand.Reader
}
for {
if _, err := io.ReadFull(r, b); err != nil {
panic(err) // This shouldn't happen
}
id := hex.EncodeToString(b)
// if we try to parse the truncated for as an int and we don't have
// an error then the value is all numeric and causes issues when
// used as a hostname. ref #3869
if _, err := strconv.ParseInt(TruncateID(id), 10, 64); err == nil {
continue
}
return id
}
}
// GenerateRandomID returns a unique id.
func GenerateRandomID() string {
return generateID(true)
}
// GenerateNonCryptoID generates unique id without using cryptographically
// secure sources of random.
// It helps you to save entropy.
func GenerateNonCryptoID() string {
return generateID(false)
}

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@@ -0,0 +1,24 @@
# Compiled Object files, Static and Dynamic libs (Shared Objects)
*.o
*.a
*.so
# Folders
_obj
_test
# Architecture specific extensions/prefixes
*.[568vq]
[568vq].out
*.cgo1.go
*.cgo2.c
_cgo_defun.c
_cgo_gotypes.go
_cgo_export.*
_testmain.go
*.exe
*.test
*.prof

View File

@@ -0,0 +1,70 @@
# Contributing to Docker open source projects
Want to hack on go-events? Awesome! Here are instructions to get you started.
go-events is part of the [Docker](https://www.docker.com) project, and
follows the same rules and principles. If you're already familiar with the way
Docker does things, you'll feel right at home.
Otherwise, go read Docker's
[contributions guidelines](https://github.com/docker/docker/blob/master/CONTRIBUTING.md),
[issue triaging](https://github.com/docker/docker/blob/master/project/ISSUE-TRIAGE.md),
[review process](https://github.com/docker/docker/blob/master/project/REVIEWING.md) and
[branches and tags](https://github.com/docker/docker/blob/master/project/BRANCHES-AND-TAGS.md).
For an in-depth description of our contribution process, visit the
contributors guide: [Understand how to contribute](https://docs.docker.com/opensource/workflow/make-a-contribution/)
### Sign your work
The sign-off is a simple line at the end of the explanation for the patch. Your
signature certifies that you wrote the patch or otherwise have the right to pass
it on as an open-source patch. The rules are pretty simple: if you can certify
the below (from [developercertificate.org](http://developercertificate.org/)):
```
Developer Certificate of Origin
Version 1.1
Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
660 York Street, Suite 102,
San Francisco, CA 94110 USA
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
Developer's Certificate of Origin 1.1
By making a contribution to this project, I certify that:
(a) The contribution was created in whole or in part by me and I
have the right to submit it under the open source license
indicated in the file; or
(b) The contribution is based upon previous work that, to the best
of my knowledge, is covered under an appropriate open source
license and I have the right under that license to submit that
work with modifications, whether created in whole or in part
by me, under the same open source license (unless I am
permitted to submit under a different license), as indicated
in the file; or
(c) The contribution was provided directly to me by some other
person who certified (a), (b) or (c) and I have not modified
it.
(d) I understand and agree that this project and the contribution
are public and that a record of the contribution (including all
personal information I submit with it, including my sign-off) is
maintained indefinitely and may be redistributed consistent with
this project or the open source license(s) involved.
```
Then you just add a line to every git commit message:
Signed-off-by: Joe Smith <joe.smith@email.com>
Use your real name (sorry, no pseudonyms or anonymous contributions.)
If you set your `user.name` and `user.email` git configs, you can sign your
commit automatically with `git commit -s`.

201
src/runtime/vendor/github.com/docker/go-events/LICENSE generated vendored Normal file
View File

@@ -0,0 +1,201 @@
Apache License
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APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "{}"
replaced with your own identifying information. (Don't include
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Copyright 2016 Docker, Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
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Unless required by applicable law or agreed to in writing, software
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

View File

@@ -0,0 +1,46 @@
# go-events maintainers file
#
# This file describes who runs the docker/go-events project and how.
# This is a living document - if you see something out of date or missing, speak up!
#
# It is structured to be consumable by both humans and programs.
# To extract its contents programmatically, use any TOML-compliant parser.
#
# This file is compiled into the MAINTAINERS file in docker/opensource.
#
[Org]
[Org."Core maintainers"]
people = [
"aaronlehmann",
"aluzzardi",
"lk4d4",
"stevvooe",
]
[people]
# A reference list of all people associated with the project.
# All other sections should refer to people by their canonical key
# in the people section.
# ADD YOURSELF HERE IN ALPHABETICAL ORDER
[people.aaronlehmann]
Name = "Aaron Lehmann"
Email = "aaron.lehmann@docker.com"
GitHub = "aaronlehmann"
[people.aluzzardi]
Name = "Andrea Luzzardi"
Email = "al@docker.com"
GitHub = "aluzzardi"
[people.lk4d4]
Name = "Alexander Morozov"
Email = "lk4d4@docker.com"
GitHub = "lk4d4"
[people.stevvooe]
Name = "Stephen Day"
Email = "stephen.day@docker.com"
GitHub = "stevvooe"

View File

@@ -0,0 +1,117 @@
# Docker Events Package
[![GoDoc](https://godoc.org/github.com/docker/go-events?status.svg)](https://godoc.org/github.com/docker/go-events)
[![Circle CI](https://circleci.com/gh/docker/go-events.svg?style=shield)](https://circleci.com/gh/docker/go-events)
The Docker `events` package implements a composable event distribution package
for Go.
Originally created to implement the [notifications in Docker Registry
2](https://github.com/docker/distribution/blob/master/docs/notifications.md),
we've found the pattern to be useful in other applications. This package is
most of the same code with slightly updated interfaces. Much of the internals
have been made available.
## Usage
The `events` package centers around a `Sink` type. Events are written with
calls to `Sink.Write(event Event)`. Sinks can be wired up in various
configurations to achieve interesting behavior.
The canonical example is that employed by the
[docker/distribution/notifications](https://godoc.org/github.com/docker/distribution/notifications)
package. Let's say we have a type `httpSink` where we'd like to queue
notifications. As a rule, it should send a single http request and return an
error if it fails:
```go
func (h *httpSink) Write(event Event) error {
p, err := json.Marshal(event)
if err != nil {
return err
}
body := bytes.NewReader(p)
resp, err := h.client.Post(h.url, "application/json", body)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.Status != 200 {
return errors.New("unexpected status")
}
return nil
}
// implement (*httpSink).Close()
```
With just that, we can start using components from this package. One can call
`(*httpSink).Write` to send events as the body of a post request to a
configured URL.
### Retries
HTTP can be unreliable. The first feature we'd like is to have some retry:
```go
hs := newHTTPSink(/*...*/)
retry := NewRetryingSink(hs, NewBreaker(5, time.Second))
```
We now have a sink that will retry events against the `httpSink` until they
succeed. The retry will backoff for one second after 5 consecutive failures
using the breaker strategy.
### Queues
This isn't quite enough. We we want a sink that doesn't block while we are
waiting for events to be sent. Let's add a `Queue`:
```go
queue := NewQueue(retry)
```
Now, we have an unbounded queue that will work through all events sent with
`(*Queue).Write`. Events can be added asynchronously to the queue without
blocking the current execution path. This is ideal for use in an http request.
### Broadcast
It usually turns out that you want to send to more than one listener. We can
use `Broadcaster` to support this:
```go
var broadcast = NewBroadcaster() // make it available somewhere in your application.
broadcast.Add(queue) // add your queue!
broadcast.Add(queue2) // and another!
```
With the above, we can now call `broadcast.Write` in our http handlers and have
all the events distributed to each queue. Because the events are queued, not
listener blocks another.
### Extending
For the most part, the above is sufficient for a lot of applications. However,
extending the above functionality can be done implementing your own `Sink`. The
behavior and semantics of the sink can be completely dependent on the
application requirements. The interface is provided below for reference:
```go
type Sink {
Write(Event) error
Close() error
}
```
Application behavior can be controlled by how `Write` behaves. The examples
above are designed to queue the message and return as quickly as possible.
Other implementations may block until the event is committed to durable
storage.
## Copyright and license
Copyright © 2016 Docker, Inc. go-events is licensed under the Apache License,
Version 2.0. See [LICENSE](LICENSE) for the full license text.

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@@ -0,0 +1,178 @@
package events
import (
"fmt"
"sync"
"github.com/sirupsen/logrus"
)
// Broadcaster sends events to multiple, reliable Sinks. The goal of this
// component is to dispatch events to configured endpoints. Reliability can be
// provided by wrapping incoming sinks.
type Broadcaster struct {
sinks []Sink
events chan Event
adds chan configureRequest
removes chan configureRequest
shutdown chan struct{}
closed chan struct{}
once sync.Once
}
// NewBroadcaster appends one or more sinks to the list of sinks. The
// broadcaster behavior will be affected by the properties of the sink.
// Generally, the sink should accept all messages and deal with reliability on
// its own. Use of EventQueue and RetryingSink should be used here.
func NewBroadcaster(sinks ...Sink) *Broadcaster {
b := Broadcaster{
sinks: sinks,
events: make(chan Event),
adds: make(chan configureRequest),
removes: make(chan configureRequest),
shutdown: make(chan struct{}),
closed: make(chan struct{}),
}
// Start the broadcaster
go b.run()
return &b
}
// Write accepts an event to be dispatched to all sinks. This method will never
// fail and should never block (hopefully!). The caller cedes the memory to the
// broadcaster and should not modify it after calling write.
func (b *Broadcaster) Write(event Event) error {
select {
case b.events <- event:
case <-b.closed:
return ErrSinkClosed
}
return nil
}
// Add the sink to the broadcaster.
//
// The provided sink must be comparable with equality. Typically, this just
// works with a regular pointer type.
func (b *Broadcaster) Add(sink Sink) error {
return b.configure(b.adds, sink)
}
// Remove the provided sink.
func (b *Broadcaster) Remove(sink Sink) error {
return b.configure(b.removes, sink)
}
type configureRequest struct {
sink Sink
response chan error
}
func (b *Broadcaster) configure(ch chan configureRequest, sink Sink) error {
response := make(chan error, 1)
for {
select {
case ch <- configureRequest{
sink: sink,
response: response}:
ch = nil
case err := <-response:
return err
case <-b.closed:
return ErrSinkClosed
}
}
}
// Close the broadcaster, ensuring that all messages are flushed to the
// underlying sink before returning.
func (b *Broadcaster) Close() error {
b.once.Do(func() {
close(b.shutdown)
})
<-b.closed
return nil
}
// run is the main broadcast loop, started when the broadcaster is created.
// Under normal conditions, it waits for events on the event channel. After
// Close is called, this goroutine will exit.
func (b *Broadcaster) run() {
defer close(b.closed)
remove := func(target Sink) {
for i, sink := range b.sinks {
if sink == target {
b.sinks = append(b.sinks[:i], b.sinks[i+1:]...)
break
}
}
}
for {
select {
case event := <-b.events:
for _, sink := range b.sinks {
if err := sink.Write(event); err != nil {
if err == ErrSinkClosed {
// remove closed sinks
remove(sink)
continue
}
logrus.WithField("event", event).WithField("events.sink", sink).WithError(err).
Errorf("broadcaster: dropping event")
}
}
case request := <-b.adds:
// while we have to iterate for add/remove, common iteration for
// send is faster against slice.
var found bool
for _, sink := range b.sinks {
if request.sink == sink {
found = true
break
}
}
if !found {
b.sinks = append(b.sinks, request.sink)
}
// b.sinks[request.sink] = struct{}{}
request.response <- nil
case request := <-b.removes:
remove(request.sink)
request.response <- nil
case <-b.shutdown:
// close all the underlying sinks
for _, sink := range b.sinks {
if err := sink.Close(); err != nil && err != ErrSinkClosed {
logrus.WithField("events.sink", sink).WithError(err).
Errorf("broadcaster: closing sink failed")
}
}
return
}
}
}
func (b *Broadcaster) String() string {
// Serialize copy of this broadcaster without the sync.Once, to avoid
// a data race.
b2 := map[string]interface{}{
"sinks": b.sinks,
"events": b.events,
"adds": b.adds,
"removes": b.removes,
"shutdown": b.shutdown,
"closed": b.closed,
}
return fmt.Sprint(b2)
}

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@@ -0,0 +1,61 @@
package events
import (
"fmt"
"sync"
)
// Channel provides a sink that can be listened on. The writer and channel
// listener must operate in separate goroutines.
//
// Consumers should listen on Channel.C until Closed is closed.
type Channel struct {
C chan Event
closed chan struct{}
once sync.Once
}
// NewChannel returns a channel. If buffer is zero, the channel is
// unbuffered.
func NewChannel(buffer int) *Channel {
return &Channel{
C: make(chan Event, buffer),
closed: make(chan struct{}),
}
}
// Done returns a channel that will always proceed once the sink is closed.
func (ch *Channel) Done() chan struct{} {
return ch.closed
}
// Write the event to the channel. Must be called in a separate goroutine from
// the listener.
func (ch *Channel) Write(event Event) error {
select {
case ch.C <- event:
return nil
case <-ch.closed:
return ErrSinkClosed
}
}
// Close the channel sink.
func (ch *Channel) Close() error {
ch.once.Do(func() {
close(ch.closed)
})
return nil
}
func (ch *Channel) String() string {
// Serialize a copy of the Channel that doesn't contain the sync.Once,
// to avoid a data race.
ch2 := map[string]interface{}{
"C": ch.C,
"closed": ch.closed,
}
return fmt.Sprint(ch2)
}

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@@ -0,0 +1,10 @@
package events
import "fmt"
var (
// ErrSinkClosed is returned if a write is issued to a sink that has been
// closed. If encountered, the error should be considered terminal and
// retries will not be successful.
ErrSinkClosed = fmt.Errorf("events: sink closed")
)

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@@ -0,0 +1,15 @@
package events
// Event marks items that can be sent as events.
type Event interface{}
// Sink accepts and sends events.
type Sink interface {
// Write an event to the Sink. If no error is returned, the caller will
// assume that all events have been committed to the sink. If an error is
// received, the caller may retry sending the event.
Write(event Event) error
// Close the sink, possibly waiting for pending events to flush.
Close() error
}

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@@ -0,0 +1,52 @@
package events
// Matcher matches events.
type Matcher interface {
Match(event Event) bool
}
// MatcherFunc implements matcher with just a function.
type MatcherFunc func(event Event) bool
// Match calls the wrapped function.
func (fn MatcherFunc) Match(event Event) bool {
return fn(event)
}
// Filter provides an event sink that sends only events that are accepted by a
// Matcher. No methods on filter are goroutine safe.
type Filter struct {
dst Sink
matcher Matcher
closed bool
}
// NewFilter returns a new filter that will send to events to dst that return
// true for Matcher.
func NewFilter(dst Sink, matcher Matcher) Sink {
return &Filter{dst: dst, matcher: matcher}
}
// Write an event to the filter.
func (f *Filter) Write(event Event) error {
if f.closed {
return ErrSinkClosed
}
if f.matcher.Match(event) {
return f.dst.Write(event)
}
return nil
}
// Close the filter and allow no more events to pass through.
func (f *Filter) Close() error {
// TODO(stevvooe): Not all sinks should have Close.
if f.closed {
return nil
}
f.closed = true
return f.dst.Close()
}

111
src/runtime/vendor/github.com/docker/go-events/queue.go generated vendored Normal file
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@@ -0,0 +1,111 @@
package events
import (
"container/list"
"sync"
"github.com/sirupsen/logrus"
)
// Queue accepts all messages into a queue for asynchronous consumption
// by a sink. It is unbounded and thread safe but the sink must be reliable or
// events will be dropped.
type Queue struct {
dst Sink
events *list.List
cond *sync.Cond
mu sync.Mutex
closed bool
}
// NewQueue returns a queue to the provided Sink dst.
func NewQueue(dst Sink) *Queue {
eq := Queue{
dst: dst,
events: list.New(),
}
eq.cond = sync.NewCond(&eq.mu)
go eq.run()
return &eq
}
// Write accepts the events into the queue, only failing if the queue has
// been closed.
func (eq *Queue) Write(event Event) error {
eq.mu.Lock()
defer eq.mu.Unlock()
if eq.closed {
return ErrSinkClosed
}
eq.events.PushBack(event)
eq.cond.Signal() // signal waiters
return nil
}
// Close shutsdown the event queue, flushing
func (eq *Queue) Close() error {
eq.mu.Lock()
defer eq.mu.Unlock()
if eq.closed {
return nil
}
// set closed flag
eq.closed = true
eq.cond.Signal() // signal flushes queue
eq.cond.Wait() // wait for signal from last flush
return eq.dst.Close()
}
// run is the main goroutine to flush events to the target sink.
func (eq *Queue) run() {
for {
event := eq.next()
if event == nil {
return // nil block means event queue is closed.
}
if err := eq.dst.Write(event); err != nil {
// TODO(aaronl): Dropping events could be bad depending
// on the application. We should have a way of
// communicating this condition. However, logging
// at a log level above debug may not be appropriate.
// Eventually, go-events should not use logrus at all,
// and should bubble up conditions like this through
// error values.
logrus.WithFields(logrus.Fields{
"event": event,
"sink": eq.dst,
}).WithError(err).Debug("eventqueue: dropped event")
}
}
}
// next encompasses the critical section of the run loop. When the queue is
// empty, it will block on the condition. If new data arrives, it will wake
// and return a block. When closed, a nil slice will be returned.
func (eq *Queue) next() Event {
eq.mu.Lock()
defer eq.mu.Unlock()
for eq.events.Len() < 1 {
if eq.closed {
eq.cond.Broadcast()
return nil
}
eq.cond.Wait()
}
front := eq.events.Front()
block := front.Value.(Event)
eq.events.Remove(front)
return block
}

260
src/runtime/vendor/github.com/docker/go-events/retry.go generated vendored Normal file
View File

@@ -0,0 +1,260 @@
package events
import (
"fmt"
"math/rand"
"sync"
"sync/atomic"
"time"
"github.com/sirupsen/logrus"
)
// RetryingSink retries the write until success or an ErrSinkClosed is
// returned. Underlying sink must have p > 0 of succeeding or the sink will
// block. Retry is configured with a RetryStrategy. Concurrent calls to a
// retrying sink are serialized through the sink, meaning that if one is
// in-flight, another will not proceed.
type RetryingSink struct {
sink Sink
strategy RetryStrategy
closed chan struct{}
once sync.Once
}
// NewRetryingSink returns a sink that will retry writes to a sink, backing
// off on failure. Parameters threshold and backoff adjust the behavior of the
// circuit breaker.
func NewRetryingSink(sink Sink, strategy RetryStrategy) *RetryingSink {
rs := &RetryingSink{
sink: sink,
strategy: strategy,
closed: make(chan struct{}),
}
return rs
}
// Write attempts to flush the events to the downstream sink until it succeeds
// or the sink is closed.
func (rs *RetryingSink) Write(event Event) error {
logger := logrus.WithField("event", event)
retry:
select {
case <-rs.closed:
return ErrSinkClosed
default:
}
if backoff := rs.strategy.Proceed(event); backoff > 0 {
select {
case <-time.After(backoff):
// TODO(stevvooe): This branch holds up the next try. Before, we
// would simply break to the "retry" label and then possibly wait
// again. However, this requires all retry strategies to have a
// large probability of probing the sync for success, rather than
// just backing off and sending the request.
case <-rs.closed:
return ErrSinkClosed
}
}
if err := rs.sink.Write(event); err != nil {
if err == ErrSinkClosed {
// terminal!
return err
}
logger := logger.WithError(err) // shadow!!
if rs.strategy.Failure(event, err) {
logger.Errorf("retryingsink: dropped event")
return nil
}
logger.Errorf("retryingsink: error writing event, retrying")
goto retry
}
rs.strategy.Success(event)
return nil
}
// Close closes the sink and the underlying sink.
func (rs *RetryingSink) Close() error {
rs.once.Do(func() {
close(rs.closed)
})
return nil
}
func (rs *RetryingSink) String() string {
// Serialize a copy of the RetryingSink without the sync.Once, to avoid
// a data race.
rs2 := map[string]interface{}{
"sink": rs.sink,
"strategy": rs.strategy,
"closed": rs.closed,
}
return fmt.Sprint(rs2)
}
// RetryStrategy defines a strategy for retrying event sink writes.
//
// All methods should be goroutine safe.
type RetryStrategy interface {
// Proceed is called before every event send. If proceed returns a
// positive, non-zero integer, the retryer will back off by the provided
// duration.
//
// An event is provided, by may be ignored.
Proceed(event Event) time.Duration
// Failure reports a failure to the strategy. If this method returns true,
// the event should be dropped.
Failure(event Event, err error) bool
// Success should be called when an event is sent successfully.
Success(event Event)
}
// Breaker implements a circuit breaker retry strategy.
//
// The current implementation never drops events.
type Breaker struct {
threshold int
recent int
last time.Time
backoff time.Duration // time after which we retry after failure.
mu sync.Mutex
}
var _ RetryStrategy = &Breaker{}
// NewBreaker returns a breaker that will backoff after the threshold has been
// tripped. A Breaker is thread safe and may be shared by many goroutines.
func NewBreaker(threshold int, backoff time.Duration) *Breaker {
return &Breaker{
threshold: threshold,
backoff: backoff,
}
}
// Proceed checks the failures against the threshold.
func (b *Breaker) Proceed(event Event) time.Duration {
b.mu.Lock()
defer b.mu.Unlock()
if b.recent < b.threshold {
return 0
}
return b.last.Add(b.backoff).Sub(time.Now())
}
// Success resets the breaker.
func (b *Breaker) Success(event Event) {
b.mu.Lock()
defer b.mu.Unlock()
b.recent = 0
b.last = time.Time{}
}
// Failure records the failure and latest failure time.
func (b *Breaker) Failure(event Event, err error) bool {
b.mu.Lock()
defer b.mu.Unlock()
b.recent++
b.last = time.Now().UTC()
return false // never drop events.
}
var (
// DefaultExponentialBackoffConfig provides a default configuration for
// exponential backoff.
DefaultExponentialBackoffConfig = ExponentialBackoffConfig{
Base: time.Second,
Factor: time.Second,
Max: 20 * time.Second,
}
)
// ExponentialBackoffConfig configures backoff parameters.
//
// Note that these parameters operate on the upper bound for choosing a random
// value. For example, at Base=1s, a random value in [0,1s) will be chosen for
// the backoff value.
type ExponentialBackoffConfig struct {
// Base is the minimum bound for backing off after failure.
Base time.Duration
// Factor sets the amount of time by which the backoff grows with each
// failure.
Factor time.Duration
// Max is the absolute maxiumum bound for a single backoff.
Max time.Duration
}
// ExponentialBackoff implements random backoff with exponentially increasing
// bounds as the number consecutive failures increase.
type ExponentialBackoff struct {
failures uint64 // consecutive failure counter (needs to be 64-bit aligned)
config ExponentialBackoffConfig
}
// NewExponentialBackoff returns an exponential backoff strategy with the
// desired config. If config is nil, the default is returned.
func NewExponentialBackoff(config ExponentialBackoffConfig) *ExponentialBackoff {
return &ExponentialBackoff{
config: config,
}
}
// Proceed returns the next randomly bound exponential backoff time.
func (b *ExponentialBackoff) Proceed(event Event) time.Duration {
return b.backoff(atomic.LoadUint64(&b.failures))
}
// Success resets the failures counter.
func (b *ExponentialBackoff) Success(event Event) {
atomic.StoreUint64(&b.failures, 0)
}
// Failure increments the failure counter.
func (b *ExponentialBackoff) Failure(event Event, err error) bool {
atomic.AddUint64(&b.failures, 1)
return false
}
// backoff calculates the amount of time to wait based on the number of
// consecutive failures.
func (b *ExponentialBackoff) backoff(failures uint64) time.Duration {
if failures <= 0 {
// proceed normally when there are no failures.
return 0
}
factor := b.config.Factor
if factor <= 0 {
factor = DefaultExponentialBackoffConfig.Factor
}
backoff := b.config.Base + factor*time.Duration(1<<(failures-1))
max := b.config.Max
if max <= 0 {
max = DefaultExponentialBackoffConfig.Max
}
if backoff > max || backoff < 0 {
backoff = max
}
// Choose a uniformly distributed value from [0, backoff).
return time.Duration(rand.Int63n(int64(backoff)))
}