cli: added role-based start command

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/cli/src/commands/index.ts

@@ -148,6 +148,19 @@ export function registerCommands(program: CommanderStatic) {
     )
     .action(lazy(() => import('./bundle').then(m => m.command)));
 
+  program
+    .command('start')
+    .description('Start a package for local development')
+    .option(...configOption)
+    .option('--role <name>', 'Run the command with an explicit package role')
+    .option('--check', 'Enable type checking and linting if available')
+    .option('--inspect', 'Enable debugger in Node.js environments')
+    .option(
+      '--inspect-brk',
+      'Enable debugger in Node.js environments, breaking before code starts',
+    )
+    .action(lazy(() => import('./start').then(m => m.command)));
+
   program
     .command('lint')
     .option(

packages/cli/src/commands/start/command.ts

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2020 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { Command } from 'commander';
+import { startBackend } from './startBackend';
+import { startFrontend } from './startFrontend';
+import { readRoleForCommand } from '../../lib/role';
+
+export async function command(cmd: Command): Promise<void> {
+  const roleInfo = await readRoleForCommand(cmd);
+
+  const options = {
+    configPaths: cmd.config as string[],
+    checksEnabled: Boolean(cmd.check),
+    inspectEnabled: Boolean(cmd.inspect),
+    inspectBrkEnabled: Boolean(cmd.inspectBrk),
+  };
+
+  switch (roleInfo.role) {
+    case 'backend':
+    case 'plugin-backend':
+    case 'plugin-backend-module':
+    case 'node-library':
+      return startBackend(options);
+    case 'app':
+      return startFrontend({
+        ...options,
+        entry: 'src/index',
+        verifyVersions: true,
+      });
+    case 'web-library':
+    case 'plugin-frontend':
+    case 'plugin-frontend-module':
+      return startFrontend({ entry: 'dev/index', ...options });
+    default:
+      throw new Error(
+        `Start command is not supported for package role '${roleInfo.role}'`,
+      );
+  }
+}

packages/cli/src/commands/start/index.ts

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2022 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export { command } from './command';

packages/cli/src/commands/start/startBackend.ts

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2020 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import fs from 'fs-extra';
+import { paths } from '../../lib/paths';
+import { serveBackend } from '../../lib/bundler';
+
+interface StartBackendOptions {
+  checksEnabled: boolean;
+  inspectEnabled: boolean;
+  inspectBrkEnabled: boolean;
+}
+
+export async function startBackend(options: StartBackendOptions) {
+  // Cleaning dist/ before we start the dev process helps work around an issue
+  // where we end up with the entrypoint executing multiple times, causing
+  // a port bind conflict among other things.
+  await fs.remove(paths.resolveTarget('dist'));
+
+  const waitForExit = await serveBackend({
+    entry: 'src/index',
+    checksEnabled: options.checksEnabled,
+    inspectEnabled: options.inspectEnabled,
+    inspectBrkEnabled: options.inspectBrkEnabled,
+  });
+
+  await waitForExit();
+}

packages/cli/src/commands/start/startFrontend.ts

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2020 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import fs from 'fs-extra';
+import chalk from 'chalk';
+import uniq from 'lodash/uniq';
+import { serveBundle } from '../../lib/bundler';
+import { loadCliConfig } from '../../lib/config';
+import { paths } from '../../lib/paths';
+import { Lockfile } from '../../lib/versioning';
+import { includedFilter } from '../versions/lint';
+
+interface StartAppOptions {
+  verifyVersions?: boolean;
+  entry: string;
+
+  checksEnabled: boolean;
+  configPaths: string[];
+}
+
+export async function startFrontend(options: StartAppOptions) {
+  if (options.verifyVersions) {
+    const lockfile = await Lockfile.load(paths.resolveTargetRoot('yarn.lock'));
+    const result = lockfile.analyze({
+      filter: includedFilter,
+    });
+    const problemPackages = [...result.newVersions, ...result.newRanges].map(
+      ({ name }) => name,
+    );
+
+    if (problemPackages.length > 1) {
+      console.log(
+        chalk.yellow(
+          `⚠️ Some of the following packages may be outdated or have duplicate installations:
+
+          ${uniq(problemPackages).join(', ')}
+        `,
+        ),
+      );
+      console.log(
+        chalk.yellow(
+          `⚠️ This can be resolved using the following command:
+
+          yarn backstage-cli versions:check --fix
+      `,
+        ),
+      );
+    }
+  }
+
+  const { name } = await fs.readJson(paths.resolveTarget('package.json'));
+  const waitForExit = await serveBundle({
+    entry: options.entry,
+    checksEnabled: options.checksEnabled,
+    ...(await loadCliConfig({
+      args: options.configPaths,
+      fromPackage: name,
+      withFilteredKeys: true,
+    })),
+  });
+
+  await waitForExit();
+}