Fallback when getent is not available

src/spec-common/commonUtils.ts

@@ -581,3 +581,14 @@ export async function getLocalUsername() {
 	}
 	return localUsername;
 }
+
+export function getEntPasswdShellCommand(userNameOrId: string) {
+	const escapedForShell = userNameOrId.replace(/['\\]/g, '\\$&');
+	const escapedForRexExp = escapeRegExpCharacters(userNameOrId)
+		.replaceAll('\'', '\\\'');
+	return `(command -v getent >/dev/null 2>&1 && getent passwd '${escapedForShell}' || grep -E '^${escapedForRexExp}|^[^:]*:[^:]*:${escapedForRexExp}:' /etc/passwd)`;
+}
+
+export function escapeRegExpCharacters(value: string): string {
+	return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}

src/spec-common/injectHeadless.ts

@@ -10,7 +10,7 @@ import * as crypto from 'crypto';
 
 import { ContainerError, toErrorText, toWarningText } from './errors';
 import { launch, ShellServer } from './shellServer';
-import { ExecFunction, CLIHost, PtyExecFunction, isFile, Exec, PtyExec } from './commonUtils';
+import { ExecFunction, CLIHost, PtyExecFunction, isFile, Exec, PtyExec, getEntPasswdShellCommand } from './commonUtils';
 import { Disposable, Event, NodeEventEmitter } from '../spec-utils/event';
 import { PackageConfiguration } from '../spec-utils/product';
 import { URI } from 'vscode-uri';
@@ -286,7 +286,7 @@ async function getUserShell(containerEnv: NodeJS.ProcessEnv, passwdUser: PasswdU
 }
 
 export async function getUserFromPasswdDB(shellServer: ShellServer, userNameOrId: string) {
-	const { stdout } = await shellServer.exec(`getent passwd ${userNameOrId}`, { logOutput: false });
+	const { stdout } = await shellServer.exec(getEntPasswdShellCommand(userNameOrId), { logOutput: false });
 	return parseUserInPasswdDB(stdout);
 }
 

src/spec-configuration/containerFeaturesConfiguration.ts

@@ -21,6 +21,7 @@ import { CommonParams, ManifestContainer, OCIManifest, OCIRef, getPublishedVersi
 import { Lockfile, readLockfile, writeLockfile } from './lockfile';
 import { computeDependsOnInstallationOrder } from './containerFeaturesOrder';
 import { logFeatureAdvisories } from './featureAdvisories';
+import { getEntPasswdShellCommand } from '../spec-common/commonUtils';
 
 // v1
 const V1_ASSET_NAME = 'devcontainer-features.tgz';
@@ -323,8 +324,8 @@ export function getFeatureLayers(featuresConfig: FeaturesConfig, containerUser:
 
 	const builtinsEnvFile = `${path.posix.join(FEATURES_CONTAINER_TEMP_DEST_FOLDER, 'devcontainer-features.builtin.env')}`;
 	let result = `RUN \\
-echo "_CONTAINER_USER_HOME=$(getent passwd ${containerUser} | cut -d: -f6)" >> ${builtinsEnvFile} && \\
-echo "_REMOTE_USER_HOME=$(getent passwd ${remoteUser} | cut -d: -f6)" >> ${builtinsEnvFile}
+echo "_CONTAINER_USER_HOME=$(${getEntPasswdShellCommand(containerUser)} | cut -d: -f6)" >> ${builtinsEnvFile} && \\
+echo "_REMOTE_USER_HOME=$(${getEntPasswdShellCommand(remoteUser)} | cut -d: -f6)" >> ${builtinsEnvFile}
 
 `;
 

src/spec-shutdown/dockerUtils.ts

@@ -3,7 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { CLIHost, runCommand, runCommandNoPty, ExecFunction, ExecParameters, Exec, PtyExecFunction, PtyExec, PtyExecParameters, plainExecAsPtyExec } from '../spec-common/commonUtils';
+import { CLIHost, runCommand, runCommandNoPty, ExecFunction, ExecParameters, Exec, PtyExecFunction, PtyExec, PtyExecParameters, plainExecAsPtyExec, escapeRegExpCharacters } from '../spec-common/commonUtils';
 import { toErrorText } from '../spec-common/errors';
 import * as ptyType from 'node-pty';
 import { Log, makeLog } from '../spec-utils/log';
@@ -351,7 +351,7 @@ function replacingDockerExecLog(original: Log, cmd: string, args: string[]) {
 }
 
 function replacingLog(original: Log, search: string, replace: string) {
-	const searchR = new RegExp(search.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'), 'g');
+	const searchR = new RegExp(escapeRegExpCharacters(search), 'g');
 	const wrapped = makeLog({
 		...original,
 		get dimensions() {

src/test/container-features/generateFeaturesConfig.test.ts

@@ -10,6 +10,7 @@ import { DevContainerConfig } from '../../spec-configuration/configuration';
 import { URI } from 'vscode-uri';
 import { getLocalCacheFolder } from '../../spec-node/utils';
 import { shellExec } from '../testUtils';
+import { getEntPasswdShellCommand } from '../../spec-common/commonUtils';
 
 export const output = makeLog(createPlainLog(text => process.stdout.write(text), () => LogLevel.Trace));
 
@@ -78,8 +79,8 @@ ENV MYKEYTWO="MY RESULT TWO"`;
         // getFeatureLayers
         const actualLayers = getFeatureLayers(featuresConfig, 'testContainerUser', 'testRemoteUser');
         const expectedLayers = `RUN \\
-echo "_CONTAINER_USER_HOME=$(getent passwd testContainerUser | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env && \\
-echo "_REMOTE_USER_HOME=$(getent passwd testRemoteUser | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env
+echo "_CONTAINER_USER_HOME=$(${getEntPasswdShellCommand('testContainerUser')} | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env && \\
+echo "_REMOTE_USER_HOME=$(${getEntPasswdShellCommand('testRemoteUser')} | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env
 
 COPY --chown=root:root --from=dev_containers_feature_content_source /tmp/build-features/first_0 /tmp/dev-container-features/first_0
 RUN chmod -R 0755 /tmp/dev-container-features/first_0 \\
@@ -140,8 +141,8 @@ RUN chmod -R 0755 /tmp/dev-container-features/second_1 \\
         // getFeatureLayers
         const actualLayers = getFeatureLayers(featuresConfig, 'testContainerUser', 'testRemoteUser');
         const expectedLayers = `RUN \\
-echo "_CONTAINER_USER_HOME=$(getent passwd testContainerUser | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env && \\
-echo "_REMOTE_USER_HOME=$(getent passwd testRemoteUser | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env
+echo "_CONTAINER_USER_HOME=$(${getEntPasswdShellCommand('testContainerUser')} | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env && \\
+echo "_REMOTE_USER_HOME=$(${getEntPasswdShellCommand('testRemoteUser')} | cut -d: -f6)" >> /tmp/dev-container-features/devcontainer-features.builtin.env
 
 
 COPY --chown=root:root --from=dev_containers_feature_content_source /tmp/build-features/color_0 /tmp/dev-container-features/color_0

src/test/getEntPasswd.test.ts

@@ -0,0 +1,66 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import { shellExec, output } from './testUtils';
+import { dockerExecFunction } from '../spec-shutdown/dockerUtils';
+import { plainExec } from '../spec-common/commonUtils';
+import { launch } from '../spec-common/shellServer';
+import { getUserFromPasswdDB } from '../spec-common/injectHeadless';
+
+describe('getEntPasswdShellCommand', function () {
+	this.timeout('20s');
+
+	[
+		{
+			image: 'busybox',
+			getentPath: undefined,
+			addUserOptions: '-D -h',
+			userName: 'foo\\bar',
+		},
+		{
+			image: 'debian',
+			getentPath: '/usr/bin/getent',
+			addUserOptions: '--disabled-password --allow-all-names --gecos "" --home',
+			userName: 'foo\\bar',
+		},
+		{
+			image: 'alpine',
+			getentPath: '/usr/bin/getent',
+			addUserOptions: '-D -h',
+			userName: 'foo_bar', // Note: Alpine doesn't support backslash in user names.
+		},
+	].forEach(({ image, getentPath, addUserOptions, userName }) => {
+		it(`should work with ${image} ${getentPath ? 'with' : 'without'} getent command`, async () => {
+			const res = await shellExec(`docker run -d ${image} sleep inf`);
+			const containerId = res.stdout.trim();
+			const exec = dockerExecFunction({
+				exec: plainExec(undefined),
+				cmd: 'docker',
+				env: {},
+				output,
+			}, containerId, 'root');
+			const shellServer = await launch(exec, output);
+
+			const which = await shellServer.exec('command -v getent')
+				.catch(() => undefined);
+			assert.strictEqual(which?.stdout.trim(), getentPath);
+
+			await shellServer.exec(`adduser ${addUserOptions} /home/foo ${userName.replaceAll('\\', '\\\\')}`);
+
+			const userByName = await getUserFromPasswdDB(shellServer, userName);
+			assert.ok(userByName);
+			assert.strictEqual(userByName.name, userName);
+			assert.strictEqual(userByName.home, '/home/foo');
+
+			const userById = await getUserFromPasswdDB(shellServer, userByName.uid);
+			assert.ok(userById);
+			assert.strictEqual(userById.name, userName);
+			assert.strictEqual(userById.home, '/home/foo');
+
+			await shellExec(`docker rm -f ${containerId}`);
+		});
+	});
+});