feat(cli): add --fallback-image flag which forces an image instead of…

… trying to detect the language

cmd/up.go

@@ -147,14 +147,15 @@ func NewUpCmd(flags *flags.GlobalFlags) *cobra.Command {
 	upCmd.Flags().StringVar(&cmd.Machine, "machine", "", "The machine to use for this workspace. The machine needs to exist beforehand or the command will fail. If the workspace already exists, this option has no effect")
 	upCmd.Flags().StringVar(&cmd.IDE, "ide", "", "The IDE to open the workspace in. If empty will use vscode locally or in browser")
 	upCmd.Flags().BoolVar(&cmd.OpenIDE, "open-ide", true, "If this is false and an IDE is configured, DevPod will only install the IDE server backend, but not open it")
-	upCmd.Flags().BoolVar(&cmd.ForceCredentials, "force-credentials", false, "If true will always use local credentials")
-	_ = upCmd.Flags().MarkHidden("force-credentials")
 	upCmd.Flags().StringVar(&cmd.GitBranch, "git-branch", "", "The git branch to use")
 	upCmd.Flags().StringVar(&cmd.GitCommit, "git-commit", "", "The git commit SHA to use")
+	upCmd.Flags().StringVar(&cmd.FallbackImage, "fallback-image", "", "The fallback image to use if no devcontainer configuration has been detected")
 
 	upCmd.Flags().BoolVar(&cmd.DisableDaemon, "disable-daemon", false, "If enabled, will not install a daemon into the target machine to track activity")
 	upCmd.Flags().StringVar(&cmd.Source, "source", "", "Optional source for the workspace. E.g. git:https://github.com/my-org/my-repo")
 	upCmd.Flags().BoolVar(&cmd.Proxy, "proxy", false, "If true will forward agent requests to stdio")
+	upCmd.Flags().BoolVar(&cmd.ForceCredentials, "force-credentials", false, "If true will always use local credentials")
+	_ = upCmd.Flags().MarkHidden("force-credentials")
 
 	// testing
 	upCmd.Flags().StringVar(&cmd.DaemonInterval, "daemon-interval", "", "TESTING ONLY")

pkg/devcontainer/run.go

@@ -133,18 +133,26 @@ func (r *runner) Up(ctx context.Context, options UpOptions) (*config.Result, err
 			return nil, err
 		}
 	} else {
-		r.Log.Warn("dev container config is missing one of \"image\", \"dockerFile\" or \"dockerComposeFile\" properties, defaulting to auto-detection")
+		if options.FallbackImage != "" {
+			r.Log.Warn("dev container config is missing one of \"image\", \"dockerFile\" or \"dockerComposeFile\" properties, using fallback image " + options.FallbackImage)
 
-		lang, err := language.DetectLanguage(r.LocalWorkspaceFolder)
-		if err != nil {
-			return nil, fmt.Errorf("could not detect project language and dev container config is missing one of \"image\", \"dockerFile\" or \"dockerComposeFile\" properties")
-		}
+			substitutedConfig.Config.ImageContainer = config.ImageContainer{
+				Image: options.FallbackImage,
+			}
+		} else {
+			r.Log.Warn("dev container config is missing one of \"image\", \"dockerFile\" or \"dockerComposeFile\" properties, defaulting to auto-detection")
+
+			lang, err := language.DetectLanguage(r.LocalWorkspaceFolder)
+			if err != nil {
+				return nil, fmt.Errorf("could not detect project language and dev container config is missing one of \"image\", \"dockerFile\" or \"dockerComposeFile\" properties")
+			}
 
-		if language.MapConfig[lang] == nil {
-			return nil, fmt.Errorf("could not detect project language and dev container config is missing one of \"image\", \"dockerFile\" or \"dockerComposeFile\" properties")
+			if language.MapConfig[lang] == nil {
+				return nil, fmt.Errorf("could not detect project language and dev container config is missing one of \"image\", \"dockerFile\" or \"dockerComposeFile\" properties")
+			}
+			substitutedConfig.Config.ImageContainer = language.MapConfig[lang].ImageContainer
 		}
 
-		substitutedConfig.Config.ImageContainer = language.MapConfig[lang].ImageContainer
 		result, err = r.runSingleContainer(ctx, substitutedConfig, substitutionContext, options)
 		if err != nil {
 			return nil, err
@@ -200,8 +208,17 @@ func (r *runner) prepare(
 			return nil, nil, errors.Wrap(err, "parsing devcontainer.json")
 		} else if rawParsedConfig == nil {
 			r.Log.Infof("Couldn't find a devcontainer.json")
-			r.Log.Infof("Try detecting project programming language...")
-			defaultConfig := language.DefaultConfig(r.LocalWorkspaceFolder, r.Log)
+			defaultConfig := &config.DevContainerConfig{}
+			if options.FallbackImage != "" {
+				r.Log.Infof("Using fallback image %s", options.FallbackImage)
+				defaultConfig.ImageContainer = config.ImageContainer{
+					Image: options.FallbackImage,
+				}
+			} else {
+				r.Log.Infof("Try detecting project programming language...")
+				defaultConfig = language.DefaultConfig(r.LocalWorkspaceFolder, r.Log)
+			}
+
 			defaultConfig.Origin = path.Join(filepath.ToSlash(r.LocalWorkspaceFolder), ".devcontainer.json")
 			err = config.SaveDevContainerJSON(defaultConfig)
 			if err != nil {

pkg/provider/workspace.go

@@ -181,6 +181,7 @@ type CLIOptions struct {
 	ForceCredentials     bool     `json:"forceCredentials,omitempty"`
 	GitBranch            string   `json:"gitBranch,omitempty"`
 	GitCommit            string   `json:"gitCommit,omitempty"`
+	FallbackImage        string   `json:"fallbackImage,omitempty"`
 
 	// build options
 	Repository string   `json:"repository,omitempty"`