agent: Support Kata agent tracing

Add configuration options to support the various Kata agent tracing
modes and types. See the comments in the built configuration files for
details:

- `cli/config/configuration-fc.toml`
- `cli/config/configuration-qemu.toml`

Fixes #1369.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

cli/config/configuration-fc.toml.in

@@ -226,6 +226,27 @@ path = "@SHIMPATH@"
 # (default: disabled)
 #enable_debug = true
 
+# Enable agent tracing.
+#
+# If enabled, the default trace mode is "dynamic" and the
+# default trace type is "isolated". The trace mode and type are set
+# explicity with the `trace_type=` and `trace_mode=` options.
+#
+# Notes:
+#
+# - Tracing is ONLY enabled when `enable_tracing` is set: explicitly
+#   setting `trace_mode=` and/or `trace_type=` without setting `enable_tracing`
+#   will NOT activate agent tracing.
+#
+# - See https://github.com/kata-containers/agent/blob/master/TRACING.md for
+#   full details.
+#
+# (default: disabled)
+#enable_tracing = true
+#
+#trace_mode = "dynamic"
+#trace_type = "isolated"
+
 [netmon]
 # If enabled, the network monitoring process gets started when the
 # sandbox is created. This allows for the detection of some additional

cli/config/configuration-qemu.toml.in

@@ -278,6 +278,27 @@ path = "@SHIMPATH@"
 # (default: disabled)
 #enable_debug = true
 
+# Enable agent tracing.
+#
+# If enabled, the default trace mode is "dynamic" and the
+# default trace type is "isolated". The trace mode and type are set
+# explicity with the `trace_type=` and `trace_mode=` options.
+#
+# Notes:
+#
+# - Tracing is ONLY enabled when `enable_tracing` is set: explicitly
+#   setting `trace_mode=` and/or `trace_type=` without setting `enable_tracing`
+#   will NOT activate agent tracing.
+#
+# - See https://github.com/kata-containers/agent/blob/master/TRACING.md for
+#   full details.
+#
+# (default: disabled)
+#enable_tracing = true
+#
+#trace_mode = "dynamic"
+#trace_type = "isolated"
+
 [netmon]
 # If enabled, the network monitoring process gets started when the
 # sandbox is created. This allows for the detection of some additional

cli/kata-env.go

@@ -27,7 +27,7 @@ import (
 //
 // XXX: Increment for every change to the output format
 // (meaning any change to the EnvInfo type).
-const formatVersion = "1.0.22"
+const formatVersion = "1.0.23"
 
 // MetaInfo stores information on the format of the output itself
 type MetaInfo struct {
@@ -112,8 +112,11 @@ type ShimInfo struct {
 
 // AgentInfo stores agent details
 type AgentInfo struct {
-	Type  string
-	Debug bool
+	Type      string
+	Debug     bool
+	Trace     bool
+	TraceMode string
+	TraceType string
 }
 
 // DistroInfo stores host operating system distribution details.
@@ -321,6 +324,9 @@ func getAgentInfo(config oci.RuntimeConfig) (AgentInfo, error) {
 			return AgentInfo{}, errors.New("cannot determine Kata agent config")
 		}
 		agent.Debug = agentConfig.Debug
+		agent.Trace = agentConfig.Trace
+		agent.TraceMode = agentConfig.TraceMode
+		agent.TraceType = agentConfig.TraceType
 	default:
 		// Nothing useful to report for the other agent types
 	}

cli/kata-env_test.go

@@ -43,6 +43,7 @@ var (
 	shimDebug       = false
 	netmonDebug     = false
 	agentDebug      = false
+	agentTrace      = false
 )
 
 // makeVersionBinary creates a shell script with the specified file
@@ -155,6 +156,7 @@ func makeRuntimeConfig(prefixDir string) (configFile string, config oci.RuntimeC
 		ShimDebug:            shimDebug,
 		NetmonDebug:          netmonDebug,
 		AgentDebug:           agentDebug,
+		AgentTrace:           agentTrace,
 	}
 
 	runtimeConfig := katatestutils.MakeRuntimeConfigFileData(configFileOptions)
@@ -217,6 +219,11 @@ func getExpectedAgentDetails(config oci.RuntimeConfig) (AgentInfo, error) {
 	return AgentInfo{
 		Type:  string(config.AgentType),
 		Debug: agentConfig.Debug,
+		Trace: agentConfig.Trace,
+
+		// No trace mode/type set by default
+		TraceMode: "",
+		TraceType: "",
 	}, nil
 }
 
@@ -496,6 +503,7 @@ func TestEnvGetEnvInfo(t *testing.T) {
 		runtimeTrace = toggle
 		shimDebug = toggle
 		agentDebug = toggle
+		agentTrace = toggle
 
 		configFile, config, err := makeRuntimeConfig(tmpdir)
 		assert.NoError(t, err)
@@ -823,6 +831,16 @@ func TestEnvGetAgentInfo(t *testing.T) {
 	assert.NoError(t, err)
 	assert.True(t, agent.Debug)
 
+	agentConfig.Trace = true
+	agentConfig.TraceMode = "traceMode"
+	agentConfig.TraceType = "traceType"
+	config.AgentConfig = agentConfig
+	agent, err = getAgentInfo(config)
+	assert.NoError(t, err)
+	assert.True(t, agent.Trace)
+	assert.Equal(t, agent.TraceMode, "traceMode")
+	assert.Equal(t, agent.TraceType, "traceType")
+
 	config.AgentConfig = "I am the wrong type"
 	_, err = getAgentInfo(config)
 	assert.Error(t, err)