proxy+pricer: pass in the entire HTTP requests for GetPrice

In this commit, we modify the `GetPrice` method and interface to accept
the full request instead of _just_ the path. For backwards compat, we
leave the path in place, but also include the full serialized HTTP
request.

pricer/defaultPricer.go

@@ -1,6 +1,9 @@
 package pricer
 
-import "context"
+import (
+	"context"
+	"net/http"
+)
 
 // DefaultPricer provides the same price for any service path. It implements
 // the Pricer interface.
@@ -16,8 +19,8 @@ func NewDefaultPricer(price int64) *DefaultPricer {
 
 // GetPrice returns the price charged for all resources of a service.
 // It is part of the Pricer interface.
-func (d *DefaultPricer) GetPrice(_ context.Context, _ string) (int64,
+func (d *DefaultPricer) GetPrice(_ context.Context,
-	error) {
+	_ *http.Request) (int64, error) {
 
 	return d.Price, nil
 }

pricer/grpcPricer.go

@@ -1,8 +1,10 @@
 package pricer
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"net/http"
 
 	"github.com/lightninglabs/aperture/pricesrpc"
 	"google.golang.org/grpc"
@@ -68,9 +70,17 @@ func NewGRPCPricer(cfg *Config) (*GRPCPricer, error) {
 
 // GetPrice queries the server for the price of a resource path and returns the
 // price. GetPrice is part of the Pricer interface.
-func (c GRPCPricer) GetPrice(ctx context.Context, path string) (int64, error) {
+func (c GRPCPricer) GetPrice(ctx context.Context,
+	r *http.Request) (int64, error) {
+
+	var b bytes.Buffer
+	if err := r.Write(&b); err != nil {
+		return 0, nil
+	}
+
 	resp, err := c.rpcClient.GetPrice(ctx, &pricesrpc.GetPriceRequest{
-		Path: path,
+		Path:            r.URL.Path,
+		HttpRequestText: b.String(),
 	})
 	if err != nil {
 		return 0, err

pricer/pricer.go

@@ -1,12 +1,15 @@
 package pricer
 
-import "context"
+import (
+	"context"
+	"net/http"
+)
 
 // Pricer is an interface used to query price data from a price provider.
 type Pricer interface {
 	// GetPrice should return the price in satoshis for the given
 	// resource path.
-	GetPrice(ctx context.Context, path string) (int64, error)
+	GetPrice(ctx context.Context, req *http.Request) (int64, error)
 
 	// Close should clean up the Pricer implementation if needed.
 	Close() error

proxy/proxy.go

@@ -155,9 +155,7 @@ func (p *Proxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		// resources.
 		acceptAuth := p.authenticator.Accept(&r.Header, resourceName)
 		if !acceptAuth {
-			price, err := target.pricer.GetPrice(
+			price, err := target.pricer.GetPrice(r.Context(), r)
-				r.Context(), r.URL.Path,
-			)
 			if err != nil {
 				prefixLog.Errorf("error getting "+
 					"resource price: %v", err)
@@ -197,7 +195,7 @@ func (p *Proxy) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			}
 			if !ok {
 				price, err := target.pricer.GetPrice(
-					r.Context(), r.URL.Path,
+					r.Context(), r,
 				)
 				if err != nil {
 					prefixLog.Errorf("error getting "+