Fetch default ports from image

Rather then default the port to 8080, if the user does not specify ports the ports exposed by the image are used. The container will also no longer assume that the port inside the container should be 8080, it is now symetrical, unless the user explicitly make it asymetrical.
sabhiram · Oct 15, 2018 · 0d15e74 · 0d15e74
1 parent ddf741d
commit 0d15e74
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Showing 3 changed files with 58 additions and 6 deletions.
diff --git a/cmd/pack/main.go b/cmd/pack/main.go
@@ -90,7 +90,7 @@ func runCommand() *cobra.Command {
 	runCommand.Flags().StringVarP(&runFlags.AppDir, "path", "p", wd, "path to app dir")
 	runCommand.Flags().StringVar(&runFlags.Builder, "builder", "packs/samples", "builder")
 	runCommand.Flags().StringVar(&runFlags.RunImage, "run-image", "packs/run", "run image")
-	runCommand.Flags().StringVar(&runFlags.Port, "port", "8080", "local port to bind")
+	runCommand.Flags().StringVar(&runFlags.Port, "port", "", "comma separated ports to publish, defaults to ports exposed by the container")
 	return runCommand
 }
 

diff --git a/run.go b/run.go
@@ -107,6 +107,12 @@ func (r *RunConfig) Run(makeStopCh func() <-chan struct{}) error {
 	}
 
 	fmt.Println("*** RUNNING:")
+	if r.Port == "" {
+		r.Port, err = r.exposedPorts(ctx, r.RepoName)
+		if err != nil {
+			return err
+		}
+	}
 	exposedPorts, portBindings, err := parsePorts(r.Port)
 	if err != nil {
 		return err
@@ -146,13 +152,25 @@ func (r *RunFlags) repoName() string {
 	return fmt.Sprintf("pack.local/run/%x", h.Sum(nil))
 }
 
+func (r *RunConfig) exposedPorts(ctx context.Context, imageID string) (string, error) {
+	i, _, err := r.Cli.ImageInspectWithRaw(ctx, imageID)
+	if err != nil {
+		return "", err
+	}
+	ports := []string{}
+	for port := range i.Config.ExposedPorts {
+		ports = append(ports, port.Port())
+	}
+	return strings.Join(ports, ","), nil
+}
+
 func parsePorts(port string) (nat.PortSet, nat.PortMap, error) {
 	ports := strings.Split(port, ",")
 	for i, p := range ports {
 		p = strings.TrimSpace(p)
 		if _, err := strconv.Atoi(p); err == nil {
-			// default simple port to localhost and 8080 inside the container
-			p = fmt.Sprintf("127.0.0.1:%s:8080/tcp", p)
+			// default simple port to localhost and inside the container
+			p = fmt.Sprintf("127.0.0.1:%s:%s/tcp", p, p)
 		}
 		ports[i] = p
 	}
@@ -172,6 +190,7 @@ func logContainerListening(log *log.Logger, portBindings nat.PortMap) {
 				if host == "127.0.0.1" {
 					host = "localhost"
 				}
+				// TODO the service may not be http based
 				log.Printf("Starting container listening at http://%s:%s/\n", host, port)
 			}
 		}

diff --git a/run_test.go b/run_test.go
@@ -165,7 +165,7 @@ func testRun(t *testing.T, when spec.G, it spec.S) {
 		it("builds an image and runs it", func() {
 			mockBuild.EXPECT().Run().Return(nil)
 
-			exposedPorts, portBindings, _ := nat.ParsePortSpecs([]string{"127.0.0.1:1370:8080/tcp"})
+			exposedPorts, portBindings, _ := nat.ParsePortSpecs([]string{"127.0.0.1:1370:1370/tcp"})
 			mockDocker.EXPECT().ContainerCreate(gomock.Any(), &container.Config{
 				Image:        subject.RepoName,
 				AttachStdout: true,
@@ -222,13 +222,46 @@ func testRun(t *testing.T, when spec.G, it spec.S) {
 			})
 		})
 
+		when("the port is not specified", func() {
+			it.Before(func() {
+				subject.Port = ""
+			})
+
+			it("gets exposed ports from the built image", func() {
+				mockBuild.EXPECT().Run().Return(nil)
+
+				exposedPorts, portBindings, _ := nat.ParsePortSpecs([]string{
+					"127.0.0.1:8080:8080/tcp",
+				})
+				mockDocker.EXPECT().ImageInspectWithRaw(gomock.Any(), subject.RepoName).Return(types.ImageInspect{
+					Config: &container.Config{
+						ExposedPorts: exposedPorts,
+					},
+				}, []byte{}, nil)
+
+				mockDocker.EXPECT().ContainerCreate(gomock.Any(), &container.Config{
+					Image:        subject.RepoName,
+					AttachStdout: true,
+					AttachStderr: true,
+					ExposedPorts: exposedPorts,
+				}, &container.HostConfig{
+					AutoRemove:   true,
+					PortBindings: portBindings,
+				}, nil, "").Return(ctr, nil)
+
+				mockDocker.EXPECT().RunContainer(gomock.Any(), ctr.ID, subject.Stdout, subject.Stderr).Return(nil)
+
+				err := subject.Run(makeStopCh)
+				assertNil(t, err)
+			})
+		})
 		when("custom ports bindings are defined", func() {
-			it("binds simple ports from localhost to the container on 8080", func() {
+			it("binds simple ports from localhost to the container on the same port", func() {
 				mockBuild.EXPECT().Run().Return(nil)
 
 				subject.Port = "1370"
 				exposedPorts, portBindings, _ := nat.ParsePortSpecs([]string{
-					"127.0.0.1:1370:8080/tcp",
+					"127.0.0.1:1370:1370/tcp",
 				})
 				mockDocker.EXPECT().ContainerCreate(gomock.Any(), &container.Config{
 					Image:        subject.RepoName,