feat: locate devcontainer.json in multiple places

envbuilder.go

@@ -127,6 +127,11 @@ type Options struct {
 	// DevcontainerDir. This can be used in cases where one wants
 	// to substitute an edited devcontainer.json file for the one
 	// that exists in the repo.
+	// If neither `DevcontainerDir` nor `DevcontainerJSONPath` is provided,
+	// envbuilder will browse following directories to locate it:
+	// 1. `.devcontainer/devcontainer.json`
+	// 2. `.devcontainer.json`
+	// 3. `.devcontainer/<folder>/devcontainer.json`
 	DevcontainerJSONPath string `env:"DEVCONTAINER_JSON_PATH"`
 
 	// DockerfilePath is a relative path to the Dockerfile that
@@ -422,22 +427,11 @@ func Run(ctx context.Context, options Options) error {
 	if options.DockerfilePath == "" {
 		// Only look for a devcontainer if a Dockerfile wasn't specified.
 		// devcontainer is a standard, so it's reasonable to be the default.
-		devcontainerDir := options.DevcontainerDir
-		if devcontainerDir == "" {
-			devcontainerDir = ".devcontainer"
-		}
-		if !filepath.IsAbs(devcontainerDir) {
-			devcontainerDir = filepath.Join(options.WorkspaceFolder, devcontainerDir)
-		}
-		devcontainerPath := options.DevcontainerJSONPath
-		if devcontainerPath == "" {
-			devcontainerPath = "devcontainer.json"
-		}
-		if !filepath.IsAbs(devcontainerPath) {
-			devcontainerPath = filepath.Join(devcontainerDir, devcontainerPath)
-		}
-		_, err := options.Filesystem.Stat(devcontainerPath)
-		if err == nil {
+		devcontainerPath, devcontainerDir, err := findDevcontainerJSON(options)
+		if err != nil {
+			logf(codersdk.LogLevelError, "Failed to locate devcontainer.json: %s", err.Error())
+			logf(codersdk.LogLevelError, "Falling back to the default image...")
+		} else {
 			// We know a devcontainer exists.
 			// Let's parse it and use it!
 			file, err := options.Filesystem.Open(devcontainerPath)
@@ -1201,3 +1195,70 @@ type osfsWithChmod struct {
 func (fs *osfsWithChmod) Chmod(name string, mode os.FileMode) error {
 	return os.Chmod(name, mode)
 }
+
+func findDevcontainerJSON(options Options) (string, string, error) {
+	// 0. Check if custom devcontainer directory or path is provided.
+	if options.DevcontainerDir != "" || options.DevcontainerJSONPath != "" {
+		devcontainerDir := options.DevcontainerDir
+		if devcontainerDir == "" {
+			devcontainerDir = ".devcontainer"
+		}
+		// If `devcontainerDir` is not an absolute path, assume it is relative to the workspace folder.
+		if !filepath.IsAbs(devcontainerDir) {
+			devcontainerDir = filepath.Join(options.WorkspaceFolder, devcontainerDir)
+		}
+
+		// An absolute location always takes a precedence.
+		devcontainerPath := options.DevcontainerJSONPath
+		if filepath.IsAbs(devcontainerPath) {
+			return options.DevcontainerJSONPath, devcontainerDir, nil
+		}
+		// If an override is not provided, assume it is just `devcontainer.json`.
+		if devcontainerPath == "" {
+			devcontainerPath = "devcontainer.json"
+		}
+
+		if !filepath.IsAbs(devcontainerPath) {
+			devcontainerPath = filepath.Join(devcontainerDir, devcontainerPath)
+		}
+		return devcontainerPath, devcontainerDir, nil
+	}
+
+	// 1. Check `options.WorkspaceFolder`/.devcontainer/devcontainer.json.
+	location := filepath.Join(options.WorkspaceFolder, ".devcontainer", "devcontainer.json")
+	if _, err := options.Filesystem.Stat(location); err == nil {
+		return location, filepath.Dir(location), nil
+	}
+
+	// 2. Check `options.WorkspaceFolder`/devcontainer.json.
+	location = filepath.Join(options.WorkspaceFolder, "devcontainer.json")
+	if _, err := options.Filesystem.Stat(location); err == nil {
+		return location, filepath.Dir(location), nil
+	}
+
+	// 3. Check every folder: `options.WorkspaceFolder`/.devcontainer/<folder>/devcontainer.json.
+	devcontainerDir := filepath.Join(options.WorkspaceFolder, ".devcontainer")
+
+	fileInfos, err := options.Filesystem.ReadDir(devcontainerDir)
+	if err != nil {
+		return "", "", err
+	}
+
+	logf := options.Logger
+	for _, fileInfo := range fileInfos {
+		if !fileInfo.IsDir() {
+			logf(codersdk.LogLevelDebug, `%s is a file`, fileInfo.Name())
+			continue
+		}
+
+		location := filepath.Join(devcontainerDir, fileInfo.Name(), "devcontainer.json")
+		if _, err := options.Filesystem.Stat(location); err != nil {
+			logf(codersdk.LogLevelDebug, `stat %s failed: %s`, location, err.Error())
+			continue
+		}
+
+		return location, filepath.Dir(location), nil
+	}
+
+	return "", "", errors.New("can't find devcontainer.json, is it a correct spec?")
+}

integration/integration_test.go

@@ -273,6 +273,53 @@ func TestBuildFromDevcontainerInCustomPath(t *testing.T) {
 	require.Equal(t, "hello", strings.TrimSpace(output))
 }
 
+func TestBuildFromDevcontainerInSubfolder(t *testing.T) {
+	t.Parallel()
+
+	// Ensures that a Git repository with a devcontainer.json is cloned and built.
+	url := createGitServer(t, gitServerOptions{
+		files: map[string]string{
+			".devcontainer/subfolder/devcontainer.json": `{
+				"name": "Test",
+				"build": {
+					"dockerfile": "Dockerfile"
+				},
+			}`,
+			".devcontainer/subfolder/Dockerfile": "FROM ubuntu",
+		},
+	})
+	ctr, err := runEnvbuilder(t, options{env: []string{
+		"GIT_URL=" + url,
+	}})
+	require.NoError(t, err)
+
+	output := execContainer(t, ctr, "echo hello")
+	require.Equal(t, "hello", strings.TrimSpace(output))
+}
+func TestBuildFromDevcontainerInRoot(t *testing.T) {
+	t.Parallel()
+
+	// Ensures that a Git repository with a devcontainer.json is cloned and built.
+	url := createGitServer(t, gitServerOptions{
+		files: map[string]string{
+			"devcontainer.json": `{
+				"name": "Test",
+				"build": {
+					"dockerfile": "Dockerfile"
+				},
+			}`,
+			"Dockerfile": "FROM ubuntu",
+		},
+	})
+	ctr, err := runEnvbuilder(t, options{env: []string{
+		"GIT_URL=" + url,
+	}})
+	require.NoError(t, err)
+
+	output := execContainer(t, ctr, "echo hello")
+	require.Equal(t, "hello", strings.TrimSpace(output))
+}
+
 func TestBuildCustomCertificates(t *testing.T) {
 	srv := httptest.NewTLSServer(createGitHandler(t, gitServerOptions{
 		files: map[string]string{