add 'templates metadata' subcommand

src/spec-node/devContainersSpecCLI.ts

@@ -44,6 +44,7 @@ import { readFeaturesConfig } from './featureUtils';
 import { featuresGenerateDocsHandler, featuresGenerateDocsOptions } from './featuresCLI/generateDocs';
 import { templatesGenerateDocsHandler, templatesGenerateDocsOptions } from './templatesCLI/generateDocs';
 import { mapNodeOSToGOOS, mapNodeArchitectureToGOARCH } from '../spec-configuration/containerCollectionsOCI';
+import { templateMetadataHandler, templateMetadataOptions } from './templatesCLI/metadata';
 
 const defaultDefaultUserEnvProbe: UserEnvProbe = 'loginInteractiveShell';
 
@@ -85,6 +86,7 @@ const mountRegex = /^type=(bind|volume),source=([^,]+),target=([^,]+)(?:,externa
 	y.command('templates', 'Templates commands', (y: Argv) => {
 		y.command('apply', 'Apply a template to the project', templateApplyOptions, templateApplyHandler);
 		y.command('publish <target>', 'Package and publish templates', templatesPublishOptions, templatesPublishHandler);
+		y.command('metadata <templateId>', 'Fetch a published Template\'s metadata', templateMetadataOptions, templateMetadataHandler);
 		y.command('generate-docs', 'Generate documentation', templatesGenerateDocsOptions, templatesGenerateDocsHandler);
 	});
 	y.command(restArgs ? ['exec', '*'] : ['exec <cmd> [args..]'], 'Execute a command on a running dev container', execOptions, execHandler);

src/spec-node/templatesCLI/metadata.ts

@@ -0,0 +1,74 @@
+import { Argv } from 'yargs';
+import { LogLevel, mapLogLevel } from '../../spec-utils/log';
+import { getPackageConfig } from '../../spec-utils/product';
+import { createLog } from '../devContainers';
+import { fetchOCIManifestIfExists, getRef } from '../../spec-configuration/containerCollectionsOCI';
+
+import { UnpackArgv } from '../devContainersSpecCLI';
+
+export function templateMetadataOptions(y: Argv) {
+	return y
+		.options({
+			'log-level': { choices: ['info' as 'info', 'debug' as 'debug', 'trace' as 'trace'], default: 'info' as 'info', description: 'Log level.' },
+		})
+		.positional('templateId', { type: 'string', demandOption: true, description: 'Template Identifier' });
+}
+
+export type TemplateMetadataArgs = UnpackArgv<ReturnType<typeof templateMetadataOptions>>;
+
+export function templateMetadataHandler(args: TemplateMetadataArgs) {
+	(async () => await templateMetadata(args))().catch(console.error);
+}
+
+async function templateMetadata({
+	'log-level': inputLogLevel,
+	'templateId': templateId,
+}: TemplateMetadataArgs) {
+	const disposables: (() => Promise<unknown> | undefined)[] = [];
+	const dispose = async () => {
+		await Promise.all(disposables.map(d => d()));
+	};
+
+	const pkg = getPackageConfig();
+
+	const output = createLog({
+		logLevel: mapLogLevel(inputLogLevel),
+		logFormat: 'text',
+		log: (str) => process.stderr.write(str),
+		terminalDimensions: undefined,
+	}, pkg, new Date(), disposables);
+
+	const params = { output, env: process.env };
+	output.write(`Fetching metadata for ${templateId}`, LogLevel.Trace);
+
+	const templateRef = getRef(output, templateId);
+	if (!templateRef) {
+		console.log(JSON.stringify({}));
+		process.exit(1);
+	}
+
+	const manifestContainer = await fetchOCIManifestIfExists(params, templateRef, undefined);
+	if (!manifestContainer) {
+		console.log(JSON.stringify({}));
+		process.exit(1);
+	}
+
+	const { manifestObj, canonicalId } = manifestContainer;
+	output.write(`Template '${templateId}' resolved to '${canonicalId}'`, LogLevel.Trace);
+
+	// Templates must have been published with a CLI post commit
+	// https://github.com/devcontainers/cli/commit/6c6aebfa7b74aea9d67760fd1e74b09573d31536
+	// in order to contain attached metadata.
+	const metadata = manifestObj.annotations?.['dev.containers.metadata'];
+	if (!metadata) {
+		output.write(`Template resolved to '${canonicalId}' but does not contain metadata on its manifest.`, LogLevel.Warning);
+		output.write(`Ask the Template owner to republish this Template to populate the manifest.`, LogLevel.Warning);
+		console.log(JSON.stringify({}));
+		process.exit(1);
+	}
+
+	const unescaped = JSON.parse(metadata);
+	console.log(JSON.stringify(unescaped));
+	await dispose();
+	process.exit();
+}

src/test/container-templates/templatesCLICommands.test.ts

@@ -17,7 +17,7 @@ const pkg = require('../../../package.json');
 describe('tests apply command', async function () {
 	this.timeout('120s');
 
-	const tmp = path.relative(process.cwd(), path.join(__dirname, 'tmp4'));
+	const tmp = path.relative(process.cwd(), path.join(__dirname, 'tmp6'));
 	const cli = `npx --prefix ${tmp} devcontainer`;
 
 	before('Install', async () => {
@@ -197,3 +197,39 @@ describe('tests generateTemplateDocumentation()', async function () {
 		assert.isFalse(invalidDocsExists);
 	});
 });
+
+describe('template metadata', async function () {
+	this.timeout('120s');
+
+	const tmp = path.relative(process.cwd(), path.join(__dirname, 'tmp7'));
+	const cli = `npx --prefix ${tmp} devcontainer`;
+
+	// https://github.com/codspace/templates/pkgs/container/templates%2Fmytemplate/255979159?tag=1.0.4
+	const templateId = 'ghcr.io/codspace/templates/mytemplate@sha256:57cbf968907c74c106b7b2446063d114743ab3f63345f7c108c577915c535185';
+
+	before('Install', async () => {
+		await shellExec(`rm -rf ${tmp}/node_modules`);
+		await shellExec(`rm -rf ${tmp}/output`);
+		await shellExec(`mkdir -p ${tmp}`);
+		await shellExec(`npm --prefix ${tmp} install devcontainers-cli-${pkg.version}.tgz`);
+	});
+
+	it('successfully fetches metdata off a published Template', async function () {
+		let success = false;
+		let result: ExecResult | undefined = undefined;
+		try {
+			result = await shellExec(`${cli} templates metadata ${templateId} --log-level trace`);
+			success = true;
+
+		} catch (error) {
+			assert.fail('features test sub-command should not throw');
+		}
+
+		assert.isTrue(success);
+		assert.isDefined(result);
+		const json = JSON.parse(result.stdout);
+		assert.strictEqual('mytemplate', json.id);
+		assert.strictEqual('Simple test', json.description);
+
+	});
+});