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

Signed-off-by: hainenber <dotronghai96@gmail.com>

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

@@ -24,6 +24,8 @@ import { LogFunc, waitForSignal } from '../../lib/run';
 import { createLogger } from '../../lib/utility';
 import { getMkdocsYml } from '@backstage/plugin-techdocs-node';
 import fs from 'fs-extra';
+import { promisify } from 'util';
+import { execFile } from 'child_process';
 
 function findPreviewBundlePath(): string {
   try {
@@ -73,6 +75,23 @@ export default async function serve(opts: OptionValues) {
     mkdocsConfigFileName,
   });
 
+  // Validate that Docker is up and running
+  if (opts.docker) {
+    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',
+      );
+    } catch {
+      logger.error(
+        'Docker is not running. Exiting. Please check status of Docker daemon with `docker info` before re-running',
+      );
+      return;
+    }
+  }
+
   let mkdocsServerHasStarted = false;
   const mkdocsLogFunc: LogFunc = data => {
     // Sometimes the lines contain an unnecessary extra new line