Merge pull request #265 from carolynvs/docker-network

Support DOCKER_NETWORK driver variable

driver/docker/docker.go

@@ -25,6 +25,12 @@ import (
 	"github.com/cnabio/cnab-go/driver"
 )
 
+const (
+	// SettingNetwork is the environment variable for the driver that specifies
+	// the docker network to which the invocation image should be attached.
+	SettingNetwork = "DOCKER_NETWORK"
+)
+
 // Driver is capable of running Docker invocation images using Docker itself.
 type Driver struct {
 	config map[string]string
@@ -93,6 +99,7 @@ func (d *Driver) Config() map[string]string {
 		"DOCKER_DRIVER_QUIET": "Make the Docker driver quiet (only print container stdout/stderr)",
 		"OUTPUTS_MOUNT_PATH":  "Absolute path to where Docker driver can create temporary directories to bundle outputs. Defaults to temp dir.",
 		"CLEANUP_CONTAINERS":  "If true, the docker container will be destroyed when it finishes running. If false, it will not be destroyed. The supported values are true and false. Defaults to true.",
+		SettingNetwork:        "Attach the invocation image to the specified docker network",
 	}
 }
 
@@ -199,21 +206,7 @@ func (d *Driver) exec(op *driver.Operation) (driver.OperationResult, error) {
 		return driver.OperationResult{}, errors.Wrap(err, "image digest validation failed")
 	}
 
-	var env []string
-	for k, v := range op.Environment {
-		env = append(env, fmt.Sprintf("%s=%v", k, v))
-	}
-
-	d.containerCfg = container.Config{
-		Image:        op.Image.Image,
-		Env:          env,
-		Entrypoint:   strslice.StrSlice{"/cnab/app/run"},
-		AttachStderr: true,
-		AttachStdout: true,
-	}
-
-	d.containerHostCfg = container.HostConfig{}
-	if err := d.ApplyConfigurationOptions(); err != nil {
+	if err := d.setConfigurationOptions(op); err != nil {
 		return driver.OperationResult{}, err
 	}
 
@@ -297,7 +290,7 @@ func (d *Driver) exec(op *driver.Operation) (driver.OperationResult, error) {
 	return opResult, err
 }
 
-// ApplyConfigurationOptions applies the configuration options set on the driver
+// ApplyConfigurationOptions applies the configuration options set on the driver by the user.
 func (d *Driver) ApplyConfigurationOptions() error {
 	for _, opt := range d.dockerConfigurationOptions {
 		if err := opt(&d.containerCfg, &d.containerHostCfg); err != nil {
@@ -307,6 +300,35 @@ func (d *Driver) ApplyConfigurationOptions() error {
 	return nil
 }
 
+// setConfigurationOptions initializes the container and host configuration options on the driver,
+// combining the default configuration with any overrides set by the user.
+func (d *Driver) setConfigurationOptions(op *driver.Operation) error {
+	var env []string
+	for k, v := range op.Environment {
+		env = append(env, fmt.Sprintf("%s=%v", k, v))
+	}
+
+	d.containerCfg = container.Config{
+		Image:        op.Image.Image,
+		Env:          env,
+		Entrypoint:   strslice.StrSlice{"/cnab/app/run"},
+		AttachStderr: true,
+		AttachStdout: true,
+	}
+
+	d.containerHostCfg = container.HostConfig{}
+
+	if network, ok := d.config[SettingNetwork]; ok {
+		d.containerHostCfg.NetworkMode = container.NetworkMode(network)
+	}
+
+	if err := d.ApplyConfigurationOptions(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func containerError(containerMessage string, containerErr, fetchErr error) error {
 	if fetchErr != nil {
 		return fmt.Errorf("%s: %v. fetching outputs failed: %s", containerMessage, containerErr, fetchErr)

driver/docker/docker_test.go

@@ -87,6 +87,46 @@ func TestDriver_GetConfigurationOptions(t *testing.T) {
 	})
 }
 
+func TestDriver_setConfigurationOptions(t *testing.T) {
+	img := "example.com/myimage"
+	op := &driver.Operation{
+		Image: bundle.InvocationImage{
+			BaseImage: bundle.BaseImage{Image: img},
+		},
+	}
+
+	t.Run("defaults", func(t *testing.T) {
+		d := &Driver{}
+
+		err := d.setConfigurationOptions(op)
+		require.NoError(t, err)
+
+		cfg := d.containerCfg
+		wantCfg := container.Config{
+			Image:        img,
+			AttachStdout: true,
+			AttachStderr: true,
+			Entrypoint:   []string{"/cnab/app/run"},
+		}
+		assert.Equal(t, wantCfg, cfg)
+
+		hostCfg := d.containerHostCfg
+		assert.Equal(t, container.HostConfig{}, hostCfg)
+	})
+
+	t.Run("docker network", func(t *testing.T) {
+		net := "mynetwork"
+		d := &Driver{}
+		d.SetConfig(map[string]string{SettingNetwork: net})
+
+		err := d.setConfigurationOptions(op)
+		require.NoError(t, err)
+
+		hostCfg := d.containerHostCfg
+		assert.Equal(t, net, string(hostCfg.NetworkMode))
+	})
+}
+
 func TestDriver_SetConfig(t *testing.T) {
 	testcases := []struct {
 		name      string