Merge pull request #1980 from dmexe/network-aliases

Add network_aliases for docker driver

client/driver/docker.go

@@ -113,6 +113,7 @@ type DockerDriverConfig struct {
 	Args             []string            `mapstructure:"args"`               // The arguments to the Command/Entrypoint
 	IpcMode          string              `mapstructure:"ipc_mode"`           // The IPC mode of the container - host and none
 	NetworkMode      string              `mapstructure:"network_mode"`       // The network mode of the container - host, nat and none
+	NetworkAliases   []string            `mapstructure:"network_aliases"`    // The network-scoped alias for the container
 	PidMode          string              `mapstructure:"pid_mode"`           // The PID mode of the container - host and none
 	UTSMode          string              `mapstructure:"uts_mode"`           // The UTS mode of the container - host and none
 	UsernsMode       string              `mapstructure:"userns_mode"`        // The User namespace mode of the container - host and none
@@ -165,6 +166,7 @@ func NewDockerDriverConfig(task *structs.Task, env *env.TaskEnvironment) (*Docke
 	dconf.Command = env.ReplaceEnv(dconf.Command)
 	dconf.IpcMode = env.ReplaceEnv(dconf.IpcMode)
 	dconf.NetworkMode = env.ReplaceEnv(dconf.NetworkMode)
+	dconf.NetworkAliases = env.ParseAndReplace(dconf.NetworkAliases)
 	dconf.PidMode = env.ReplaceEnv(dconf.PidMode)
 	dconf.UTSMode = env.ReplaceEnv(dconf.UTSMode)
 	dconf.Hostname = env.ReplaceEnv(dconf.Hostname)
@@ -272,6 +274,9 @@ func (d *DockerDriver) Validate(config map[string]interface{}) error {
 			"network_mode": &fields.FieldSchema{
 				Type: fields.TypeString,
 			},
+			"network_aliases": &fields.FieldSchema{
+				Type: fields.TypeArray,
+			},
 			"pid_mode": &fields.FieldSchema{
 				Type: fields.TypeString,
 			},
@@ -838,10 +843,22 @@ func (d *DockerDriver) createContainerConfig(ctx *ExecContext, task *structs.Tas
 	containerName := fmt.Sprintf("%s-%s", task.Name, ctx.AllocID)
 	d.logger.Printf("[DEBUG] driver.docker: setting container name to: %s", containerName)
 
+	networkingConfig := &docker.NetworkingConfig{
+		EndpointsConfig: make(map[string]*docker.EndpointConfig),
+	}
+
+	if len(driverConfig.NetworkAliases) > 0 {
+		networkingConfig.EndpointsConfig[hostConfig.NetworkMode] = &docker.EndpointConfig{
+			Aliases: driverConfig.NetworkAliases,
+		}
+		d.logger.Printf("[DEBUG] driver.docker: applied network aliases on the container: [%s]%+v", hostConfig.NetworkMode, driverConfig.NetworkAliases)
+	}
+
 	return docker.CreateContainerOptions{
-		Name:       containerName,
-		Config:     config,
-		HostConfig: hostConfig,
+		Name:             containerName,
+		Config:           config,
+		HostConfig:       hostConfig,
+		NetworkingConfig: networkingConfig,
 	}, nil
 }
 

client/driver/docker_test.go

@@ -87,15 +87,11 @@ func dockerTask() (*structs.Task, int, int) {
 // If there is a problem during setup this function will abort or skip the test
 // and indicate the reason.
 func dockerSetup(t *testing.T, task *structs.Task) (*docker.Client, DriverHandle, func()) {
-	if !testutil.DockerIsConnected(t) {
-		t.SkipNow()
-	}
-
-	client, err := docker.NewClientFromEnv()
-	if err != nil {
-		t.Fatalf("Failed to initialize client: %s\nStack\n%s", err, debug.Stack())
-	}
+	client := newTestDockerClient(t)
+	return dockerSetupWithClient(t, task, client)
+}
 
+func dockerSetupWithClient(t *testing.T, task *structs.Task, client *docker.Client) (*docker.Client, DriverHandle, func()) {
 	driverCtx, execCtx := testDriverContexts(task)
 	driverCtx.config.Options = map[string]string{"docker.cleanup.image": "false"}
 	driver := NewDockerDriver(driverCtx)
@@ -119,6 +115,18 @@ func dockerSetup(t *testing.T, task *structs.Task) (*docker.Client, DriverHandle
 	return client, handle, cleanup
 }
 
+func newTestDockerClient(t *testing.T) *docker.Client {
+	if !testutil.DockerIsConnected(t) {
+		t.SkipNow()
+	}
+
+	client, err := docker.NewClientFromEnv()
+	if err != nil {
+		t.Fatalf("Failed to initialize client: %s\nStack\n%s", err, debug.Stack())
+	}
+	return client
+}
+
 // This test should always pass, even if docker daemon is not available
 func TestDockerDriver_Fingerprint(t *testing.T) {
 	driverCtx, execCtx := testDriverContexts(&structs.Task{Name: "foo", Resources: basicResources})
@@ -589,6 +597,51 @@ func TestDockerDriver_NetworkMode_Host(t *testing.T) {
 	}
 }
 
+func TestDockerDriver_NetworkAliases_Bridge(t *testing.T) {
+	// Because go-dockerclient doesn't provide api for query network aliases, just check that
+	// a container can be created with a 'network_aliases' property
+
+	// Create network, network-scoped alias is supported only for containers in user defined networks
+	client := newTestDockerClient(t)
+	networkOpts := docker.CreateNetworkOptions{Name: "foobar", Driver: "bridge"}
+	network, err := client.CreateNetwork(networkOpts)
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer client.RemoveNetwork(network.ID)
+
+	expected := []string{"foobar"}
+	task := &structs.Task{
+		Name: "nc-demo",
+		Config: map[string]interface{}{
+			"image":           "busybox",
+			"load":            []string{"busybox.tar"},
+			"command":         "/bin/nc",
+			"args":            []string{"-l", "127.0.0.1", "-p", "0"},
+			"network_mode":    network.Name,
+			"network_aliases": expected,
+		},
+		Resources: &structs.Resources{
+			MemoryMB: 256,
+			CPU:      512,
+		},
+		LogConfig: &structs.LogConfig{
+			MaxFiles:      10,
+			MaxFileSizeMB: 10,
+		},
+	}
+
+	client, handle, cleanup := dockerSetupWithClient(t, task, client)
+	defer cleanup()
+
+	waitForExist(t, client, handle.(*DockerHandle))
+
+	_, err = client.InspectContainer(handle.(*DockerHandle).ContainerID())
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+}
+
 func TestDockerDriver_Labels(t *testing.T) {
 	task, _, _ := dockerTask()
 	task.Config["labels"] = []map[string]string{

website/source/docs/drivers/docker.html.md

@@ -126,6 +126,21 @@ The `docker` driver supports the following configuration in the job spec:
   pre-docker 1.9 are `default`, `bridge`, `host`, `none`, or `container:name`.
   See below for more details.
 
+* `network_aliases` - (Optional) A list of network-scoped aliases, provide a way for a
+  container to be discovered by an alternate name by any other container within
+  the scope of a particular network. Network-scoped alias is supported only for
+  containers in user defined networks
+
+    ```hcl
+    config {
+      network_mode = "overlay"
+      network_aliases = [
+        "${NOMAD_TASK_NAME}",
+        "${NOMAD_TASK_NAME}-${NOMAD_ALLOC_INDEX}"
+      ]
+    }
+    ```
+
 * `hostname` - (Optional) The hostname to assign to the container. When
   launching more than one of a task (using `count`) with this option set, every
   container the task starts will have the same hostname.