Port 'docker version' to the engine API

api.go

@@ -140,7 +140,8 @@ func postAuth(srv *Server, version float64, w http.ResponseWriter, r *http.Reque
 }
 
 func getVersion(srv *Server, version float64, w http.ResponseWriter, r *http.Request, vars map[string]string) error {
-	return writeJSON(w, http.StatusOK, srv.DockerVersion())
+	srv.Eng.ServeHTTP(w, r)
+	return nil
 }
 
 func postContainersKill(srv *Server, version float64, w http.ResponseWriter, r *http.Request, vars map[string]string) error {

api_params.go

@@ -95,12 +95,6 @@ type (
 		IP          string
 	}
 
-	APIVersion struct {
-		Version   string
-		GitCommit string `json:",omitempty"`
-		GoVersion string `json:",omitempty"`
-	}
-
 	APIWait struct {
 		StatusCode int
 	}

commands.go

@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"github.com/dotcloud/docker/archive"
 	"github.com/dotcloud/docker/auth"
+	"github.com/dotcloud/docker/engine"
 	"github.com/dotcloud/docker/registry"
 	"github.com/dotcloud/docker/term"
 	"github.com/dotcloud/docker/utils"
@@ -391,26 +392,24 @@ func (cli *DockerCli) CmdVersion(args ...string) error {
 		return err
 	}
 
-	var out APIVersion
-	err = json.Unmarshal(body, &out)
+	out := engine.NewOutput()
+	remoteVersion, err := out.AddEnv()
 	if err != nil {
-		utils.Errorf("Error unmarshal: body: %s, err: %s\n", body, err)
+		utils.Errorf("Error reading remote version: %s\n", err)
 		return err
 	}
-	if out.Version != "" {
-		fmt.Fprintf(cli.out, "Server version: %s\n", out.Version)
+	if _, err := out.Write(body); err != nil {
+		utils.Errorf("Error reading remote version: %s\n", err)
+		return err
 	}
-	if out.GitCommit != "" {
-		fmt.Fprintf(cli.out, "Git commit (server): %s\n", out.GitCommit)
-	}
-	if out.GoVersion != "" {
-		fmt.Fprintf(cli.out, "Go version (server): %s\n", out.GoVersion)
-	}
-
+	out.Close()
+	fmt.Fprintf(cli.out, "Server version: %s\n", remoteVersion.Get("Version"))
+	fmt.Fprintf(cli.out, "Git commit (server): %s\n", remoteVersion.Get("GitCommit"))
+	fmt.Fprintf(cli.out, "Go version (server): %s\n", remoteVersion.Get("GoVersion"))
 	release := utils.GetReleaseVersion()
 	if release != "" {
 		fmt.Fprintf(cli.out, "Last stable version: %s", release)
-		if (VERSION != "" || out.Version != "") && (strings.Trim(VERSION, "-dev") != release || strings.Trim(out.Version, "-dev") != release) {
+		if (VERSION != "" || remoteVersion.Exists("Version")) && (strings.Trim(VERSION, "-dev") != release || strings.Trim(remoteVersion.Get("Version"), "-dev") != release) {
 			fmt.Fprintf(cli.out, ", please update docker")
 		}
 		fmt.Fprintf(cli.out, "\n")

integration/api_test.go

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"github.com/dotcloud/docker"
+	"github.com/dotcloud/docker/engine"
 	"github.com/dotcloud/docker/utils"
 	"io"
 	"net"
@@ -35,12 +36,18 @@ func TestGetVersion(t *testing.T) {
 	}
 	assertHttpNotError(r, t)
 
-	v := &docker.APIVersion{}
-	if err = json.Unmarshal(r.Body.Bytes(), v); err != nil {
+	out := engine.NewOutput()
+	v, err := out.AddEnv()
+	if err != nil {
 		t.Fatal(err)
 	}
-	if v.Version != docker.VERSION {
-		t.Errorf("Expected version %s, %s found", docker.VERSION, v.Version)
+	if _, err := io.Copy(out, r.Body); err != nil {
+		t.Fatal(err)
+	}
+	out.Close()
+	expected := docker.VERSION
+	if result := v.Get("Version"); result != expected {
+		t.Errorf("Expected version %s, %s found", expected, result)
 	}
 }
 

server.go

@@ -118,14 +118,6 @@ func (srv *Server) ListenAndServe(job *engine.Job) engine.Status {
 	return engine.StatusOK
 }
 
-func (srv *Server) DockerVersion() APIVersion {
-	return APIVersion{
-		Version:   VERSION,
-		GitCommit: GITCOMMIT,
-		GoVersion: runtime.Version(),
-	}
-}
-
 // simpleVersionInfo is a simple implementation of
 // the interface VersionInfo, which is used
 // to provide version information for some product,