Mount a worktree's common folder for Git operations

Author: chrmarti

src/spec-node/singleContainer.ts

@@ -51,7 +51,7 @@ export async function openDockerfileDevContainer(params: DockerResolverParameter
 			// collapsedFeaturesConfig = async () => res.collapsedFeaturesConfig;
 
 			try {
-				await spawnDevContainer(params, config, mergedConfig, updatedImageName, idLabels, workspaceConfig.workspaceMount, res.imageDetails, containerUser, res.labels || {});
+				await spawnDevContainer(params, config, mergedConfig, updatedImageName, idLabels, workspaceConfig.workspaceMount, workspaceConfig.additionalMountString, res.imageDetails, containerUser, res.labels || {});
 			} finally {
 				// In 'finally' because 'docker run' can fail after creating the container.
 				// Trying to get it here, so we can offer 'Rebuild Container' as an action later.
@@ -348,7 +348,7 @@ export async function extraRunArgs(common: ResolverParameters, params: DockerRes
 	return extraArguments;
 }
 
-export async function spawnDevContainer(params: DockerResolverParameters, config: DevContainerFromDockerfileConfig | DevContainerFromImageConfig, mergedConfig: MergedDevContainerConfig, imageName: string, labels: string[], workspaceMount: string | undefined, imageDetails: () => Promise<ImageDetails>, containerUser: string | undefined, extraLabels: Record<string, string>) {
+export async function spawnDevContainer(params: DockerResolverParameters, config: DevContainerFromDockerfileConfig | DevContainerFromImageConfig, mergedConfig: MergedDevContainerConfig, imageName: string, labels: string[], workspaceMount: string | undefined, additionalMountString: string | undefined, imageDetails: () => Promise<ImageDetails>, containerUser: string | undefined, extraLabels: Record<string, string>) {
 	const { common } = params;
 	common.progress(ResolverProgress.StartingContainer);
 
@@ -357,6 +357,7 @@ export async function spawnDevContainer(params: DockerResolverParameters, config
 	const exposed = (<string[]>[]).concat(...exposedPorts.map(port => ['-p', typeof port === 'number' ? `127.0.0.1:${port}:${port}` : port]));
 
 	const cwdMount = workspaceMount ? ['--mount', workspaceMount] : [];
+	const additionalMount = additionalMountString ? ['--mount', additionalMountString] : [];
 
 	const envObj = mergedConfig.containerEnv || {};
 	const containerEnv = Object.keys(envObj)
@@ -409,6 +410,7 @@ while sleep 1 & wait $!; do :; done`, '-']; // `wait $!` allows for the `trap` t
 		'-a', 'STDERR',
 		...exposed,
 		...cwdMount,
+		...additionalMount,
 		...featureMounts,
 		...getLabels(labels),
 		...containerEnv,

src/spec-node/utils.ts

@@ -347,24 +347,58 @@ export async function getHostMountFolder(cliHost: CLIHost, folderPath: string, m
 export interface WorkspaceConfiguration {
 	workspaceMount: string | undefined;
 	workspaceFolder: string | undefined;
+	additionalMountString: string | undefined;
 }
 
 export async function getWorkspaceConfiguration(cliHost: CLIHost, workspace: Workspace | undefined, config: DevContainerConfig, mountWorkspaceGitRoot: boolean, output: Log, consistency?: BindMountConsistency): Promise<WorkspaceConfiguration> {
 	if ('dockerComposeFile' in config) {
 		return {
 			workspaceFolder: getRemoteWorkspaceFolder(config),
 			workspaceMount: undefined,
+			additionalMountString: undefined,
 		};
 	}
 	let { workspaceFolder, workspaceMount } = config;
+	let additionalMountString: string | undefined;
 	if (workspace && (!workspaceFolder || !('workspaceMount' in config))) {
 		const hostMountFolder = await getHostMountFolder(cliHost, workspace.rootFolderPath, mountWorkspaceGitRoot, output);
+
+		// Check if .git is a file (worktree) with a relative gitdir path
+		let containerMountFolder = path.posix.join('/workspaces', cliHost.path.basename(hostMountFolder));
+		if (mountWorkspaceGitRoot) {
+			const dotGitPath = cliHost.path.join(hostMountFolder, '.git');
+			if (await cliHost.isFile(dotGitPath)) {
+				const dotGitContent = (await cliHost.readFile(dotGitPath)).toString();
+				const match = /^gitdir:\s*(.+)$/m.exec(dotGitContent);
+				if (match) {
+					const gitdir = match[1];
+					// Only handle if gitdir is a relative path
+					if (!cliHost.path.isAbsolute(gitdir)) {
+						// gitdir points to .git/worktrees/<name>/, common dir is .git/ (two levels up)
+						const gitCommonDir = cliHost.path.resolve(hostMountFolder, gitdir, '..', '..');
+						// Collect path segments from hostMountFolder up to the parent of gitCommonDir
+						const segments: string[] = [];
+						for (let current = hostMountFolder; !gitCommonDir.startsWith(current + cliHost.path.sep) && current !== cliHost.path.dirname(current); current = cliHost.path.dirname(current)) {
+							segments.unshift(cliHost.path.basename(current));
+						}
+						containerMountFolder = path.posix.join('/workspaces', ...segments);
+						// Calculate where the common dir should be mounted in the container
+						const containerGitdir = cliHost.platform === 'win32' ? gitdir.replace(/\\/g, '/') : gitdir;
+						const containerGitCommonDir = path.posix.resolve(containerMountFolder, containerGitdir, '..', '..');
+						const cons = cliHost.platform !== 'linux' ? `,consistency=${consistency || 'consistent'}` : '';
+						const srcQuote = gitCommonDir.indexOf(',') !== -1 ? '"' : '';
+						const tgtQuote = containerGitCommonDir.indexOf(',') !== -1 ? '"' : '';
+						additionalMountString = `type=bind,${srcQuote}source=${gitCommonDir}${srcQuote},${tgtQuote}target=${containerGitCommonDir}${tgtQuote}${cons}`;
+					}
+				}
+			}
+		}
+
 		if (!workspaceFolder) {
-			const rel = cliHost.path.relative(cliHost.path.dirname(hostMountFolder), workspace.rootFolderPath);
-			workspaceFolder = `/workspaces/${cliHost.platform === 'win32' ? rel.replace(/\\/g, '/') : rel}`;
+			const rel = cliHost.path.relative(hostMountFolder, workspace.rootFolderPath);
+			workspaceFolder = path.posix.join(containerMountFolder, cliHost.platform === 'win32' ? rel.replace(/\\/g, '/') : rel);
 		}
 		if (!('workspaceMount' in config)) {
-			const containerMountFolder = `/workspaces/${cliHost.path.basename(hostMountFolder)}`;
 			const cons = cliHost.platform !== 'linux' ? `,consistency=${consistency || 'consistent'}` : ''; // Podman does not tolerate consistency=
 			const srcQuote = hostMountFolder.indexOf(',') !== -1 ? '"' : '';
 			const tgtQuote = containerMountFolder.indexOf(',') !== -1 ? '"' : '';
@@ -374,6 +408,7 @@ export async function getWorkspaceConfiguration(cliHost: CLIHost, workspace: Wor
 	return {
 		workspaceFolder,
 		workspaceMount,
+		additionalMountString,
 	};
 }