backend-common: Add runDockerContainer shared by Scaffolder and TechDocs

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

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

@@ -14,12 +14,10 @@
  * limitations under the License.
  */
 import { getVoidLogger } from '@backstage/backend-common';
-import Docker from 'dockerode';
 import fs from 'fs-extra';
 import mockFs from 'mock-fs';
 import os from 'os';
 import path, { resolve as resolvePath } from 'path';
-import Stream, { PassThrough } from 'stream';
 import { ParsedLocationAnnotation } from '../../helpers';
 import { RemoteProtocol } from '../prepare/types';
 import {
@@ -28,9 +26,7 @@ import {
   getRepoUrlFromLocationAnnotation,
   isValidRepoUrlForMkdocs,
   patchMkdocsYmlPreBuild,
-  runDockerContainer,
   storeEtagMetadata,
-  UserOptions,
 } from './helpers';
 
 const mockEntity = {
@@ -41,8 +37,6 @@ const mockEntity = {
   },
 };
 
-const mockDocker = new Docker() as jest.Mocked<Docker>;
-
 const mkdocsYml = fs.readFileSync(
   resolvePath(__filename, '../__fixtures__/mkdocs.yml'),
 );
@@ -60,133 +54,6 @@ describe('helpers', () => {
     });
   });
 
-  describe('runDockerContainer', () => {
-    beforeEach(() => {
-      jest.spyOn(mockDocker, 'pull').mockImplementation((async (
-        _image: string,
-        _something: any,
-        handler: (err: Error | undefined, stream: PassThrough) => void,
-      ) => {
-        const mockStream = new PassThrough();
-        handler(undefined, mockStream);
-        mockStream.end();
-      }) as any);
-
-      jest
-        .spyOn(mockDocker, 'run')
-        .mockResolvedValue([{ Error: null, StatusCode: 0 }]);
-
-      jest
-        .spyOn(mockDocker, 'ping')
-        .mockResolvedValue(Buffer.from('OK', 'utf-8'));
-    });
-
-    const imageName = 'spotify/techdocs';
-    const args = ['build', '-d', '/result'];
-    const docsDir = os.tmpdir();
-    const outputDir = os.tmpdir();
-
-    it('should pull the techdocs docker container', async () => {
-      await runDockerContainer({
-        imageName,
-        args,
-        docsDir,
-        outputDir,
-        dockerClient: mockDocker,
-      });
-
-      expect(mockDocker.pull).toHaveBeenCalledWith(
-        imageName,
-        {},
-        expect.any(Function),
-      );
-    });
-
-    it('should run the techdocs docker container', async () => {
-      await runDockerContainer({
-        imageName,
-        args,
-        docsDir,
-        outputDir,
-        dockerClient: mockDocker,
-      });
-
-      expect(mockDocker.run).toHaveBeenCalledWith(
-        imageName,
-        args,
-        expect.any(Stream),
-        expect.objectContaining({
-          Volumes: {
-            '/content': {},
-            '/result': {},
-          },
-          WorkingDir: '/content',
-          HostConfig: {
-            Binds: [`${docsDir}:/content`, `${outputDir}:/result`],
-          },
-        }),
-      );
-    });
-
-    it('should ping docker to test availability', async () => {
-      await runDockerContainer({
-        imageName,
-        args,
-        docsDir,
-        outputDir,
-        dockerClient: mockDocker,
-      });
-
-      expect(mockDocker.ping).toHaveBeenCalled();
-    });
-
-    it('should pass through the user and group id from the host machine and set the home dir', async () => {
-      await runDockerContainer({
-        imageName,
-        args,
-        docsDir,
-        outputDir,
-        dockerClient: mockDocker,
-      });
-
-      const userOptions: UserOptions = {};
-      if (process.getuid && process.getgid) {
-        userOptions.User = `${process.getuid()}:${process.getgid()}`;
-      }
-
-      expect(mockDocker.run).toHaveBeenCalledWith(
-        imageName,
-        args,
-        expect.any(Stream),
-        expect.objectContaining({
-          ...userOptions,
-        }),
-      );
-    });
-
-    describe('where docker is unavailable', () => {
-      const dockerError = 'a docker error';
-
-      beforeEach(() => {
-        jest.spyOn(mockDocker, 'ping').mockImplementationOnce(() => {
-          throw new Error(dockerError);
-        });
-      });
-
-      it('should throw with a descriptive error message including the docker error message', async () => {
-        await expect(
-          runDockerContainer({
-            imageName,
-            args,
-            docsDir,
-            outputDir,
-            dockerClient: mockDocker,
-          }),
-        ).rejects.toThrow(new RegExp(`.+: ${dockerError}`));
-      });
-    });
-  });
-
   describe('isValidRepoUrlForMkdocs', () => {
     it('should return true for valid repo_url values for mkdocs', () => {
       const validRepoUrls = [

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

@@ -16,7 +16,6 @@
 
 import { Entity } from '@backstage/catalog-model';
 import { spawn } from 'child_process';
-import Docker from 'dockerode';
 import fs from 'fs-extra';
 import yaml from 'js-yaml';
 import { PassThrough, Writable } from 'stream';
@@ -34,16 +33,6 @@ export function getGeneratorKey(entity: Entity): SupportedGeneratorKey {
   return 'techdocs';
 }
 
-type RunDockerContainerOptions = {
-  imageName: string;
-  args: string[];
-  logStream?: Writable;
-  docsDir: string;
-  outputDir: string;
-  dockerClient: Docker;
-  createOptions?: Docker.ContainerCreateOptions;
-};
-
 export type RunCommandOptions = {
   command: string;
   args: string[];
@@ -51,83 +40,6 @@ export type RunCommandOptions = {
   logStream?: Writable;
 };
 
-export type UserOptions = {
-  User?: string;
-};
-
-// To be replaced by a runDockerContainer from backend-common
-// shared between Scaffolder and TechDocs and any other plugin.
-export async function runDockerContainer({
-  imageName,
-  args,
-  logStream = new PassThrough(),
-  docsDir,
-  outputDir,
-  dockerClient,
-  createOptions,
-}: RunDockerContainerOptions) {
-  try {
-    await dockerClient.ping();
-  } catch (e) {
-    throw new Error(
-      `This operation requires Docker. Docker does not appear to be available. Docker.ping() failed with: ${e.message}`,
-    );
-  }
-
-  await new Promise<void>((resolve, reject) => {
-    dockerClient.pull(imageName, {}, (err, stream) => {
-      if (err) return reject(err);
-      stream.pipe(logStream, { end: false });
-      stream.on('end', () => resolve());
-      stream.on('error', (error: Error) => reject(error));
-      return undefined;
-    });
-  });
-
-  const userOptions: UserOptions = {};
-  // @ts-ignore
-  if (process.getuid && process.getgid) {
-    // Files that are created inside the Docker container will be owned by
-    // root on the host system on non Mac systems, because of reasons. Mainly the fact that
-    // volume sharing is done using NFS on Mac and actual mounts in Linux world.
-    // So we set the user in the container as the same user and group id as the host.
-    // On Windows we don't have process.getuid nor process.getgid
-    userOptions.User = `${process.getuid()}:${process.getgid()}`;
-  }
-
-  const [{ Error: error, StatusCode: statusCode }] = await dockerClient.run(
-    imageName,
-    args,
-    logStream,
-    {
-      Volumes: {
-        '/content': {},
-        '/result': {},
-      },
-      WorkingDir: '/content',
-      HostConfig: {
-        Binds: [`${docsDir}:/content`, `${outputDir}:/result`],
-      },
-      ...userOptions,
-      ...createOptions,
-    },
-  );
-
-  if (error) {
-    throw new Error(
-      `Docker failed to run with the following error message: ${error}`,
-    );
-  }
-
-  if (statusCode !== 0) {
-    throw new Error(
-      `Docker container returned a non-zero exit code (${statusCode})`,
-    );
-  }
-
-  return { error, statusCode };
-}
-
 /**
  *
  * @param options the options object

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

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import { runDockerContainer } from '@backstage/backend-common';
 import { Config } from '@backstage/config';
 import path from 'path';
 import { PassThrough } from 'stream';
@@ -22,7 +23,6 @@ import {
   addBuildTimestampMetadata,
   patchMkdocsYmlPreBuild,
   runCommand,
-  runDockerContainer,
   storeEtagMetadata,
 } from './helpers';
 import { GeneratorBase, GeneratorRunOptions } from './types';
@@ -96,9 +96,9 @@ export class TechdocsGenerator implements GeneratorBase {
         case 'docker':
           await runDockerContainer({
             imageName: 'spotify/techdocs',
-            args: ['build', '-d', '/result'],
+            args: ['build', '-d', '/output'],
             logStream,
-            docsDir: inputDir,
+            inputDir,
             outputDir,
             dockerClient,
           });