[proxy] refactoring out common marshalling logic

proxy/common.go

@@ -40,6 +40,19 @@ func callWeave(args ...string) ([]byte, []byte, error) {
 	return stdout.Bytes(), stderr.Bytes(), err
 }
 
+func unmarshalRequestBody(r *http.Request, target interface{}) error {
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		return err
+	}
+	if err := r.Body.Close(); err != nil {
+		return err
+	}
+	r.Body = ioutil.NopCloser(bytes.NewReader(body))
+
+	return json.Unmarshal(body, &target)
+}
+
 func marshalRequestBody(r *http.Request, body interface{}) error {
 	newBody, err := json.Marshal(body)
 	if err != nil {
@@ -50,6 +63,32 @@ func marshalRequestBody(r *http.Request, body interface{}) error {
 	return nil
 }
 
+func unmarshalResponseBody(r *http.Response, target interface{}) error {
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		return err
+	}
+	if err := r.Body.Close(); err != nil {
+		return err
+	}
+	r.Body = ioutil.NopCloser(bytes.NewReader(body))
+
+	return json.Unmarshal(body, &target)
+}
+
+func marshalResponseBody(r *http.Response, body interface{}) error {
+	newBody, err := json.Marshal(body)
+	if err != nil {
+		return err
+	}
+	r.Body = ioutil.NopCloser(bytes.NewReader(newBody))
+	r.ContentLength = int64(len(newBody))
+	// Stop it being chunked, because that hangs
+	r.TransferEncoding = nil
+	return nil
+
+}
+
 func inspectContainerInPath(client *docker.Client, path string) (*docker.Container, error) {
 	subs := containerIDRegexp.FindStringSubmatch(path)
 	if subs == nil {

proxy/create_container_interceptor.go

@@ -1,8 +1,6 @@
 package proxy
 
 import (
-	"bytes"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -42,15 +40,8 @@ func (err *ErrNoSuchImage) Error() string {
 }
 
 func (i *createContainerInterceptor) InterceptRequest(r *http.Request) error {
-	body, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return err
-	}
-	r.Body.Close()
-	r.Body = ioutil.NopCloser(bytes.NewReader(body))
-
 	container := createContainerRequestBody{}
-	if err := json.Unmarshal(body, &container); err != nil {
+	if err := unmarshalRequestBody(r, &container); err != nil {
 		return err
 	}
 
@@ -74,12 +65,7 @@ func (i *createContainerInterceptor) InterceptRequest(r *http.Request) error {
 			return err
 		}
 
-		newBody, err := json.Marshal(container)
-		if err != nil {
-			return err
-		}
-		r.Body = ioutil.NopCloser(bytes.NewReader(newBody))
-		r.ContentLength = int64(len(newBody))
+		return marshalRequestBody(r, container)
 	}
 
 	return nil

proxy/create_exec_interceptor.go

@@ -1,9 +1,6 @@
 package proxy
 
 import (
-	"bytes"
-	"encoding/json"
-	"io/ioutil"
 	"net/http"
 	"strings"
 
@@ -14,15 +11,8 @@ import (
 type createExecInterceptor struct{ proxy *Proxy }
 
 func (i *createExecInterceptor) InterceptRequest(r *http.Request) error {
-	body, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return err
-	}
-	r.Body.Close()
-	r.Body = ioutil.NopCloser(bytes.NewReader(body))
-
 	options := docker.CreateExecOptions{}
-	if err := json.Unmarshal(body, &options); err != nil {
+	if err := unmarshalRequestBody(r, &options); err != nil {
 		return err
 	}
 

proxy/inspect_container_interceptor.go

@@ -1,9 +1,6 @@
 package proxy
 
 import (
-	"bytes"
-	"encoding/json"
-	"io/ioutil"
 	"net/http"
 
 	"github.com/fsouza/go-dockerclient"
@@ -21,14 +18,8 @@ func (i *inspectContainerInterceptor) InterceptResponse(r *http.Response) error
 		return nil
 	}
 
-	body, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return err
-	}
-	r.Body.Close()
-
 	container := &docker.Container{}
-	if err := json.Unmarshal(body, container); err != nil {
+	if err := unmarshalResponseBody(r, container); err != nil {
 		return err
 	}
 
@@ -36,15 +27,7 @@ func (i *inspectContainerInterceptor) InterceptResponse(r *http.Response) error
 		Log.Warningf("Inspecting container %s failed: %s", container.ID, err)
 	}
 
-	newBody, err := json.Marshal(container)
-	if err != nil {
-		return err
-	}
-	r.Body = ioutil.NopCloser(bytes.NewReader(newBody))
-	r.ContentLength = int64(len(newBody))
-	r.TransferEncoding = nil // Stop it being chunked, because that hangs
-
-	return nil
+	return marshalResponseBody(r, container)
 }
 
 func updateContainerNetworkSettings(container *docker.Container) error {

proxy/inspect_exec_interceptor.go

@@ -1,9 +1,6 @@
 package proxy
 
 import (
-	"bytes"
-	"encoding/json"
-	"io/ioutil"
 	"net/http"
 
 	"github.com/fsouza/go-dockerclient"
@@ -21,14 +18,8 @@ func (i *inspectExecInterceptor) InterceptResponse(r *http.Response) error {
 		return nil
 	}
 
-	body, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		return err
-	}
-	r.Body.Close()
-
 	exec := &docker.ExecInspect{}
-	if err := json.Unmarshal(body, exec); err != nil {
+	if err := unmarshalResponseBody(r, &exec); err != nil {
 		return err
 	}
 
@@ -36,13 +27,5 @@ func (i *inspectExecInterceptor) InterceptResponse(r *http.Response) error {
 		Log.Warningf("Inspecting exec %s failed: %s", exec.ID, err)
 	}
 
-	newBody, err := json.Marshal(exec)
-	if err != nil {
-		return err
-	}
-	r.Body = ioutil.NopCloser(bytes.NewReader(newBody))
-	r.ContentLength = int64(len(newBody))
-	r.TransferEncoding = nil // Stop it being chunked, because that hangs
-
-	return nil
+	return marshalResponseBody(r, exec)
 }