1. Use plain Record instead of Map

2. Call fs.realpath inside the utility function

Signed-off-by: Himanshu Mishra <himanshu@orkohunter.net>

packages/backend-common/src/util/docker.test.ts

@@ -57,10 +57,10 @@ describe('runDockerContainer', () => {
 
   const imageName = 'dockerOrg/image';
   const args = ['bash', '-c', 'echo test'];
-  const mountDirs = new Map([
-    [path.join(rootDir, 'input'), '/input'],
-    [path.join(rootDir, 'output'), '/output'],
-  ]);
+  const mountDirs = {
+    [path.join(rootDir, 'input')]: '/input',
+    [path.join(rootDir, 'output')]: '/output',
+  };
   const workingDir = path.join(rootDir, 'input');
   const envVars = ['HOME=/tmp', 'LOG_LEVEL=debug'];
 

packages/backend-common/src/util/docker.ts

@@ -15,6 +15,7 @@
  */
 
 import Docker from 'dockerode';
+import fs from 'fs-extra';
 import { PassThrough, Writable } from 'stream';
 
 export type UserOptions = {
@@ -26,7 +27,7 @@ export type RunDockerContainerOptions = {
   args: string[];
   logStream?: Writable;
   dockerClient: Docker;
-  mountDirs?: Map<string, string>;
+  mountDirs?: Record<string, string>;
   workingDir?: string;
   envVars?: string[];
   createOptions?: Docker.ContainerCreateOptions;
@@ -40,7 +41,7 @@ export type RunDockerContainerOptions = {
  * @param options.logStream the log streamer to capture log messages
  * @param options.dockerClient the dockerClient to use
  * @param options.mountDirs A map of host directories to mount on the container.
- *        Map Key: Path on host machine, Value: Path on Docker container
+ *        Object Key: Path on host machine, Value: Path on Docker container
  * @param options.workingDir Working dir in the container
  * @param options.envVars Environment variables to set in the container. e.g. ['HOME=/tmp']
  */
@@ -49,7 +50,7 @@ export const runDockerContainer = async ({
   args,
   logStream = new PassThrough(),
   dockerClient,
-  mountDirs = new Map(),
+  mountDirs = {},
   workingDir,
   envVars = [],
   createOptions = {},
@@ -85,14 +86,17 @@ export const runDockerContainer = async ({
 
   // Initialize volumes to mount based on mountDirs map
   const Volumes: { [T: string]: object } = {};
-  for (const containerDir of mountDirs.values()) {
+  for (const containerDir of Object.values(mountDirs)) {
     Volumes[containerDir] = {};
   }
 
   // Create bind volumes
   const Binds: string[] = [];
-  for (const [hostDir, containerDir] of mountDirs.entries()) {
-    Binds.push(`${hostDir}:${containerDir}`);
+  for (const [hostDir, containerDir] of Object.entries(mountDirs)) {
+    // Need to use realpath here as Docker mounting does not like
+    // symlinks for binding volumes
+    const realHostDir = await fs.realpath(hostDir);
+    Binds.push(`${realHostDir}:${containerDir}`);
   }
 
   const [{ Error: error, StatusCode: statusCode }] = await dockerClient.run(

packages/techdocs-common/src/stages/generate/techdocs.ts

@@ -16,7 +16,6 @@
 
 import { runDockerContainer } from '@backstage/backend-common';
 import { Config } from '@backstage/config';
-import fs from 'fs-extra';
 import path from 'path';
 import { PassThrough } from 'stream';
 import { Logger } from 'winston';
@@ -80,12 +79,10 @@ export class TechdocsGenerator implements GeneratorBase {
     }
 
     // Directories to bind on container
-    const mountDirs = new Map([
-      // Need to use realpath here as Docker mounting does not like
-      // symlinks for binding volumes
-      [await fs.realpath(inputDir), '/input'],
-      [await fs.realpath(outputDir), '/output'],
-    ]);
+    const mountDirs = {
+      [inputDir]: '/input',
+      [outputDir]: '/output',
+    };
 
     try {
       switch (this.options.runGeneratorIn) {

plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.test.ts

@@ -160,10 +160,10 @@ describe('CookieCutter Templater', () => {
         '--verbose',
       ],
       envVars: ['HOME=/tmp'],
-      mountDirs: new Map([
-        [path.join('tempdir', 'template'), '/input'],
-        [path.join('tempdir', 'intermediate'), '/output'],
-      ]),
+      mountDirs: {
+        [path.join('tempdir', 'template')]: '/input',
+        [path.join('tempdir', 'intermediate')]: '/output',
+      },
       workingDir: '/input',
       logStream: undefined,
       dockerClient: mockDocker,
@@ -203,10 +203,10 @@ describe('CookieCutter Templater', () => {
         '--verbose',
       ],
       envVars: ['HOME=/tmp'],
-      mountDirs: new Map([
-        [path.join('tempdir', 'template'), '/input'],
-        [path.join('tempdir', 'intermediate'), '/output'],
-      ]),
+      mountDirs: {
+        [path.join('tempdir', 'template')]: '/input',
+        [path.join('tempdir', 'intermediate')]: '/output',
+      },
       workingDir: '/input',
       logStream: stream,
       dockerClient: mockDocker,

plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.ts

@@ -59,12 +59,10 @@ export class CookieCutter implements TemplaterBase {
     await fs.writeJSON(path.join(templateDir, 'cookiecutter.json'), cookieInfo);
 
     // Directories to bind on container
-    const mountDirs = new Map([
-      // Need to use realpath here as Docker mounting does not like
-      // symlinks for binding volumes
-      [await fs.realpath(templateDir), '/input'],
-      [await fs.realpath(intermediateDir), '/output'],
-    ]);
+    const mountDirs = {
+      [templateDir]: '/input',
+      [intermediateDir]: '/output',
+    };
 
     const cookieCutterInstalled = await commandExists('cookiecutter');
     if (cookieCutterInstalled) {

plugins/scaffolder-backend/src/scaffolder/stages/templater/cra/index.ts

@@ -40,10 +40,10 @@ export class CreateReactAppTemplater implements TemplaterBase {
     const intermediateDir = path.join(workspacePath, 'template');
     await fs.ensureDir(intermediateDir);
 
-    const mountDirs = new Map([
-      [await fs.realpath(intermediateDir), '/template'],
-      [await fs.realpath(intermediateDir), '/result'],
-    ]);
+    const mountDirs = {
+      [intermediateDir]: '/template',
+      [intermediateDir]: '/result',
+    };
 
     await runDockerContainer({
       imageName: 'node:lts-alpine',