feat: support setting up existing container as devcontainer

cmd/agent/workspace/delete.go

@@ -82,11 +82,15 @@ func removeContainer(ctx context.Context, workspaceInfo *provider2.AgentWorkspac
 		return err
 	}
 
-	err = runner.Delete(ctx)
-	if err != nil {
-		return err
+	if workspaceInfo.Workspace.Source.Container != "" {
+		log.Infof("Skipping container deletion, since it was not created by DevPod")
+	} else {
+		err = runner.Delete(ctx)
+		if err != nil {
+			return err
+		}
+		log.Debugf("Successfully removed DevPod container from server")
 	}
-	log.Debugf("Successfully removed DevPod container from server")
 
 	return nil
 }

cmd/agent/workspace/up.go

@@ -202,9 +202,12 @@ func prepareWorkspace(ctx context.Context, workspaceInfo *provider2.AgentWorkspa
 	} else if workspaceInfo.Workspace.Source.Image != "" {
 		log.Debugf("Prepare Image")
 		return PrepareImage(workspaceInfo.ContentFolder, workspaceInfo.Workspace.Source.Image)
+	} else if workspaceInfo.Workspace.Source.Container != "" {
+		log.Debugf("Workspace is a container, nothing to do")
+		return nil
 	}
 
-	return fmt.Errorf("either workspace repository, image or local-folder is required")
+	return fmt.Errorf("either workspace repository, image, container or local-folder is required")
 }
 
 func InitContentFolder(workspaceInfo *provider2.AgentWorkspaceInfo, log log.Logger) (bool, error) {

e2e/tests/up/docker.go

@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/docker/docker/api/types"
 	"github.com/loft-sh/devpod/e2e/framework"
 	"github.com/loft-sh/devpod/pkg/devcontainer/config"
 	docker "github.com/loft-sh/devpod/pkg/docker"
@@ -51,6 +52,43 @@ var _ = DevPodDescribe("devpod up test suite", func() {
 				err = f.DevPodUp(ctx, tempDir)
 				framework.ExpectNoError(err)
 			}, ginkgo.SpecTimeout(framework.GetTimeout()))
+			ginkgo.It("should start a new workspace with existing running container", func(ctx context.Context) {
+				tempDir, err := framework.CopyToTempDir("tests/up/testdata/no-devcontainer")
+				framework.ExpectNoError(err)
+				ginkgo.DeferCleanup(framework.CleanupTempDir, initialDir, tempDir)
+
+				f := framework.NewDefaultFramework(initialDir + "/bin")
+
+				_ = f.DevPodProviderDelete(ctx, "docker")
+				err = f.DevPodProviderAdd(ctx, "docker")
+				framework.ExpectNoError(err)
+				err = f.DevPodProviderUse(ctx, "docker")
+				framework.ExpectNoError(err)
+
+				err = dockerHelper.Run(ctx, []string{"run", "-d", "--label", "devpod-e2e-test-container=true", "-w", "/workspaces/e2e", "mcr.microsoft.com/vscode/devcontainers/base:alpine", "sleep", "infinity"}, nil, nil, nil)
+				framework.ExpectNoError(err)
+
+				ids, err := dockerHelper.FindContainer(ctx, []string{
+					"devpod-e2e-test-container=true",
+				})
+				framework.ExpectNoError(err)
+				gomega.Expect(ids).To(gomega.HaveLen(1), "1 container is created")
+				ginkgo.DeferCleanup(dockerHelper.Remove, ids[0])
+				ginkgo.DeferCleanup(dockerHelper.Stop, ids[0])
+
+				var containerDetails []types.ContainerJSON
+				err = dockerHelper.Inspect(ctx, ids, "container", &containerDetails)
+				framework.ExpectNoError(err)
+
+				containerDetail := containerDetails[0]
+				gomega.Expect(containerDetail.Config.WorkingDir).To(gomega.Equal("/workspaces/e2e"))
+
+				ginkgo.DeferCleanup(f.DevPodWorkspaceDelete, context.Background(), tempDir)
+
+				// Wait for devpod workspace to come online (deadline: 30s)
+				err = f.DevPodUp(ctx, tempDir, "--source", fmt.Sprintf("container:%s", containerDetail.ID))
+				framework.ExpectNoError(err)
+			}, ginkgo.SpecTimeout(framework.GetTimeout()))
 			ginkgo.It("should start a new workspace and substitute devcontainer.json variables", func(ctx context.Context) {
 				tempDir, err := framework.CopyToTempDir("tests/up/testdata/docker-variables")
 				framework.ExpectNoError(err)

pkg/devcontainer/config/config.go

@@ -17,6 +17,7 @@ type MergedDevContainerConfig struct {
 	ImageContainer          `json:",inline"`
 	ComposeContainer        `json:",inline"`
 	DockerfileContainer     `json:",inline"`
+	RunningContainer        `json:",inline"`
 
 	// Origin is the origin from where this config was loaded
 	Origin string `json:"-"`
@@ -29,6 +30,7 @@ type DevContainerConfig struct {
 	ImageContainer         `json:",inline"`
 	ComposeContainer       `json:",inline"`
 	DockerfileContainer    `json:",inline"`
+	RunningContainer       `json:",inline"`
 
 	// Origin is the origin from where this config was loaded
 	Origin string `json:"-"`
@@ -217,6 +219,10 @@ type DockerfileContainer struct {
 	Build *ConfigBuildOptions `json:"build,omitempty"`
 }
 
+type RunningContainer struct {
+	ContainerID string `json:"containerID,omitempty"`
+}
+
 func (d DockerfileContainer) GetDockerfile() string {
 	if d.Dockerfile != "" {
 		return d.Dockerfile

pkg/devcontainer/config/container_details.go

@@ -23,6 +23,9 @@ type ContainerDetails struct {
 type ContainerDetailsConfig struct {
 	Labels map[string]string `json:"Labels,omitempty"`
 
+	// WorkingDir specifies default working directory inside the container
+	WorkingDir string `json:"WorkingDir,omitempty"`
+
 	// LegacyUser shouldn't get used anymore and is only there for backwards compatibility, please
 	// use the label config.UserLabel instead
 	LegacyUser string `json:"User,omitempty"`

pkg/devcontainer/run.go

@@ -116,7 +116,7 @@ func (r *runner) Up(ctx context.Context, options UpOptions) (*config.Result, err
 
 	// check if its a compose devcontainer.json
 	var result *config.Result
-	if isDockerFileConfig(substitutedConfig.Config) || substitutedConfig.Config.Image != "" {
+	if isDockerFileConfig(substitutedConfig.Config) || substitutedConfig.Config.Image != "" || substitutedConfig.Config.ContainerID != "" {
 		result, err = r.runSingleContainer(
 			ctx,
 			substitutedConfig,
@@ -165,6 +165,18 @@ func (r *runner) prepare(
 		} else {
 			rawParsedConfig.Origin = path.Join(filepath.ToSlash(r.LocalWorkspaceFolder), ".devcontainer.devpod.json")
 		}
+	} else if r.WorkspaceConfig.Workspace.Source.Container != "" {
+		rawParsedConfig = &config.DevContainerConfig{
+			DevContainerConfigBase: config.DevContainerConfigBase{
+				// Default workspace directory for containers
+				// Upon inspecting the container, this would be updated to the correct folder, if found set
+				WorkspaceFolder: "/",
+			},
+			RunningContainer: config.RunningContainer{
+				ContainerID: r.WorkspaceConfig.Workspace.Source.Container,
+			},
+			Origin: "",
+		}
 	} else {
 		var err error
 

pkg/devcontainer/single.go

@@ -25,7 +25,10 @@ func (r *runner) runSingleContainer(ctx context.Context, parsedConfig *config.Su
 	var (
 		mergedConfig *config.MergedDevContainerConfig
 	)
-	if !options.Recreate && containerDetails != nil {
+	// if options.Recreate is true, and workspace is a running container, we should not rebuild
+	if options.Recreate && parsedConfig.Config.ContainerID != "" {
+		return nil, fmt.Errorf("cannot recreate container not created by DevPod")
+	} else if !options.Recreate && containerDetails != nil {
 		// start container if not running
 		if strings.ToLower(containerDetails.State.Status) != "running" {
 			err = r.Driver.StartDevContainer(ctx, r.ID)
@@ -34,6 +37,11 @@ func (r *runner) runSingleContainer(ctx context.Context, parsedConfig *config.Su
 			}
 		}
 
+		// if we are working with a non-managed container, and it has set workingDir, set it as the workspaceFolder
+		if parsedConfig.Config.ContainerID != "" && containerDetails.Config.WorkingDir != "" {
+			substitutionContext.ContainerWorkspaceFolder = containerDetails.Config.WorkingDir
+		}
+
 		imageMetadataConfig, err := metadata.GetImageMetadataFromContainer(containerDetails, substitutionContext, r.Log)
 		if err != nil {
 			return nil, err

pkg/docker/helper.go

@@ -19,6 +19,10 @@ import (
 
 type DockerHelper struct {
 	DockerCommand string
+	// for a running container, we cannot pass down the container ID to the driver without introducing
+	// changes in the driver interface (which we do not want to do). So, to get around this, we pass
+	// it down to the driver during docker helper initialization.
+	ContainerID string
 	// allow command to have a custom environment
 	Environment []string
 }

pkg/driver/docker/docker.go

@@ -45,6 +45,7 @@ func NewDockerDriver(workspaceInfo *provider2.AgentWorkspaceInfo, log log.Logger
 		Docker: &docker.DockerHelper{
 			DockerCommand: dockerCommand,
 			Environment:   makeEnvironment(workspaceInfo.Agent.Docker.Env, log),
+			ContainerID:   workspaceInfo.Workspace.Source.Container,
 		},
 		Log: log,
 	}
@@ -151,7 +152,13 @@ func (d *dockerDriver) ComposeHelper() (*compose.ComposeHelper, error) {
 }
 
 func (d *dockerDriver) FindDevContainer(ctx context.Context, workspaceId string) (*config.ContainerDetails, error) {
-	containerDetails, err := d.Docker.FindDevContainer(ctx, []string{config.DockerIDLabel + "=" + workspaceId})
+	var containerDetails *config.ContainerDetails
+	var err error
+	if d.Docker.ContainerID != "" {
+		containerDetails, err = d.Docker.FindContainerByID(ctx, []string{d.Docker.ContainerID})
+	} else {
+		containerDetails, err = d.Docker.FindDevContainer(ctx, []string{config.DockerIDLabel + "=" + workspaceId})
+	}
 	if err != nil {
 		return nil, err
 	} else if containerDetails == nil {

pkg/provider/workspace.go

@@ -10,9 +10,10 @@ import (
 )
 
 var (
-	WorkspaceSourceGit   = "git:"
-	WorkspaceSourceLocal = "local:"
-	WorkspaceSourceImage = "image:"
+	WorkspaceSourceGit       = "git:"
+	WorkspaceSourceLocal     = "local:"
+	WorkspaceSourceImage     = "image:"
+	WorkspaceSourceContainer = "container:"
 )
 
 type Workspace struct {
@@ -108,6 +109,9 @@ type WorkspaceSource struct {
 
 	// Image is the docker image to use
 	Image string `json:"image,omitempty"`
+
+	// Container is the container to use
+	Container string `json:"container,omitempty"`
 }
 
 type ContainerWorkspaceInfo struct {
@@ -203,6 +207,8 @@ func (w WorkspaceSource) String() string {
 		return WorkspaceSourceLocal + w.LocalFolder
 	} else if w.Image != "" {
 		return WorkspaceSourceImage + w.Image
+	} else if w.Container != "" {
+		return WorkspaceSourceContainer + w.Container
 	}
 
 	return ""
@@ -225,6 +231,10 @@ func ParseWorkspaceSource(source string) *WorkspaceSource {
 		return &WorkspaceSource{
 			Image: strings.TrimPrefix(source, WorkspaceSourceImage),
 		}
+	} else if strings.HasPrefix(source, WorkspaceSourceContainer) {
+		return &WorkspaceSource{
+			Container: strings.TrimPrefix(source, WorkspaceSourceContainer),
+		}
 	}
 
 	return nil

pkg/workspace/workspace.go

@@ -207,6 +207,14 @@ func ResolveWorkspace(
 		}
 	}
 
+	// configure dev container source
+	if workspace.Source.Container != "" {
+		err = provider2.SaveWorkspaceConfig(workspace)
+		if err != nil {
+			return nil, errors.Wrap(err, "save workspace")
+		}
+	}
+
 	// create workspace client
 	var workspaceClient client.BaseWorkspaceClient
 	if provider.IsProxyProvider() {