Merge pull request #20978 from hainenber/docker-status-check-for-mkdocs-server

feat(techdocs-cli): check Docker status before running mkdocs server

.changeset/selfish-games-deny.md

@@ -0,0 +1,5 @@
+---
+'@techdocs/cli': minor
+---
+
+validate Docker status before running mkdocs server

packages/techdocs-cli/src/commands/serve/mkdocs.ts

@@ -21,6 +21,7 @@ import { runMkdocsServer } from '../../lib/mkdocsServer';
 import { LogFunc, waitForSignal } from '../../lib/run';
 import { getMkdocsYml } from '@backstage/plugin-techdocs-node';
 import fs from 'fs-extra';
+import { checkIfDockerIsOperational } from './utils';
 
 export default async function serveMkdocs(opts: OptionValues) {
   const logger = createLogger({ verbose: opts.verbose });
@@ -29,6 +30,13 @@ export default async function serveMkdocs(opts: OptionValues) {
   const localAddr = `http://127.0.0.1:${opts.port}`;
   const expectedDevAddr = opts.docker ? dockerAddr : localAddr;
 
+  if (opts.docker) {
+    const isDockerOperational = await checkIfDockerIsOperational(logger);
+    if (!isDockerOperational) {
+      return;
+    }
+  }
+
   const { path: mkdocsYmlPath, configIsTemporary } = await getMkdocsYml(
     './',
     opts.siteName,

packages/techdocs-cli/src/commands/serve/serve.ts

@@ -24,6 +24,7 @@ import { LogFunc, waitForSignal } from '../../lib/run';
 import { createLogger } from '../../lib/utility';
 import { getMkdocsYml } from '@backstage/plugin-techdocs-node';
 import fs from 'fs-extra';
+import { checkIfDockerIsOperational } from './utils';
 
 function findPreviewBundlePath(): string {
   try {
@@ -73,6 +74,14 @@ export default async function serve(opts: OptionValues) {
     mkdocsConfigFileName,
   });
 
+  // Validate that Docker is up and running
+  if (opts.docker) {
+    const isDockerOperational = await checkIfDockerIsOperational(logger);
+    if (!isDockerOperational) {
+      return;
+    }
+  }
+
   let mkdocsServerHasStarted = false;
   const mkdocsLogFunc: LogFunc = data => {
     // Sometimes the lines contain an unnecessary extra new line

packages/techdocs-cli/src/commands/serve/utils.ts

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2023 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 { promisify } from 'util';
+import * as winston from 'winston';
+import { execFile } from 'child_process';
+
+export async function checkIfDockerIsOperational(
+  logger: winston.Logger,
+): Promise<boolean> {
+  logger.info('Checking Docker status...');
+  try {
+    const runCheck = promisify(execFile);
+    await runCheck('docker', ['info'], { shell: true });
+    logger.info(
+      'Docker is up and running. Proceed to starting up mkdocs server',
+    );
+    return true;
+  } catch {
+    logger.error(
+      'Docker is not running. Exiting. Please check status of Docker daemon with `docker info` before re-running',
+    );
+    return false;
+  }
+}