Merge pull request #403 from spotify/rugvip/build-cache

cli: add experimental build-cache command and make sure things are only built on change in CI

.github/workflows/frontend.yml

@@ -14,6 +14,8 @@ jobs:
 
     env:
       CI: true
+      BACKSTAGE_CACHE_DIR: <repoRoot>/.backstage-build-cache
+      BACKSTAGE_CACHE_MAX_ENTRIES: 2
 
     steps:
       - uses: actions/checkout@v2
@@ -34,6 +36,13 @@ jobs:
         with:
           path: node_modules
           key: ${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
+      - name: cache build cache
+        uses: actions/cache@v1
+        with:
+          path: .backstage-build-cache
+          key: build-cache-${{ github.sha }}
+          restore-keys: |
+            build-cache-
       - name: use node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v1
         with:
@@ -43,5 +52,7 @@ jobs:
       - run: yarn lint
       - run: yarn build
       - run: yarn test
+      - name: yarn bundle, if app was changed
+        run: git diff --quiet origin/master HEAD -- packages/app packages/core || yarn bundle
       - name: verify storybook
         run: yarn workspace storybook build-storybook

.github/workflows/master.yml

@@ -14,6 +14,8 @@ jobs:
 
     env:
       CI: true
+      BACKSTAGE_CACHE_DIR: <repoRoot>/.backstage-build-cache
+      BACKSTAGE_CACHE_MAX_ENTRIES: 2
 
     steps:
       - uses: actions/checkout@v2
@@ -32,6 +34,13 @@ jobs:
         with:
           path: node_modules
           key: ${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
+      - name: cache build cache
+        uses: actions/cache@v1
+        with:
+          path: .backstage-build-cache
+          key: build-cache-${{ github.sha }}
+          restore-keys: |
+            build-cache-
       - name: use node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v1
         with:

package.json

@@ -6,11 +6,12 @@
   },
   "scripts": {
     "start": "yarn build && yarn workspace example-app start",
+    "bundle": "yarn build && yarn workspace example-app bundle",
     "build": "lerna run build",
     "test": "cross-env CI=true lerna run test --since origin/master -- --coverage",
     "create-plugin": "backstage-cli create-plugin",
     "release": "if [ \"$(git symbolic-ref --short HEAD)\" = master ]; then echo \"don't try to release master\"; exit 1; else lerna version --no-push; fi",
-    "lint": "lerna run lint",
+    "lint": "cross-env CI=true lerna run lint --since origin/master --",
     "storybook": "yarn workspace storybook start"
   },
   "workspaces": {

packages/app/package.json

@@ -26,7 +26,7 @@
   },
   "scripts": {
     "start": "backstage-cli app:serve",
-    "build": "backstage-cli app:build",
+    "bundle": "backstage-cli app:build",
     "test": "backstage-cli test",
     "test:e2e": "start-server-and-test start http://localhost:3000 cy:dev",
     "test:e2e:ci": "start-server-and-test start http://localhost:3000 cy:run",

packages/cli/package.json

@@ -19,7 +19,7 @@
   "main": "dist",
   "scripts": {
     "exec": "npx ts-node ./src",
-    "build": "tsc --outDir dist --noEmit false --module CommonJS",
+    "build": "backstage-cli build-cache -- tsc --outDir dist --noEmit false --module CommonJS",
     "lint": "backstage-cli lint",
     "test": "backstage-cli test",
     "start": "nodemon ."
@@ -32,10 +32,12 @@
     "@types/ora": "^3.2.0",
     "@types/react-dev-utils": "^9.0.4",
     "@types/recursive-readdir": "^2.2.0",
+    "@types/tar": "^4.0.3",
     "@types/webpack": "^4.41.7",
     "@types/webpack-dev-server": "^3.10.0",
     "del": "^5.1.0",
     "nodemon": "^2.0.2",
+    "tar": "^6.0.1",
     "ts-node": "^8.6.2"
   },
   "bin": {

packages/cli/src/commands/build-cache/archive.ts

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 tar from 'tar';
+import { dirname } from 'path';
+
+// packages all files in inputDir into an archive at archivePath, deleting any existing archive
+export async function createArchive(
+  archivePath: string,
+  inputDir: string,
+): Promise<void> {
+  await fs.remove(archivePath);
+  await fs.ensureDir(dirname(archivePath));
+  await tar.create({ gzip: true, file: archivePath, cwd: inputDir }, ['.']);
+}
+
+// extracts archive at archive path into outputDir, deleting any existing files at outputDir
+export async function extractArchive(
+  archivePath: string,
+  outputDir: string,
+): Promise<void> {
+  await fs.remove(outputDir);
+  await fs.ensureDir(outputDir);
+  await tar.extract({ file: archivePath, cwd: outputDir });
+}

packages/cli/src/commands/build-cache/cache.ts

@@ -0,0 +1,195 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 { resolve as resolvePath, relative as relativePath } from 'path';
+import { runPlain, runCheck } from '../../helpers/run';
+import { Options } from './options';
+import { extractArchive, createArchive } from './archive';
+
+const INFO_FILE = '.backstage-build-cache';
+
+// Result from a cache query
+export type CacheQueryResult = {
+  // True if there was a cache hit
+  hit: boolean;
+  // If there is a cache hit and this method is defined, it needs to be called to restore the
+  // output contents before continuing.
+  copy?: (outputDir: string) => Promise<void>;
+  // Call after a successful build to archive the output content.
+  // The content will be archived using the same key as was used to query the cache.
+  archive: (outputDir: string, maxEntries: number) => Promise<void>;
+};
+
+// Key that determines whether cached output can be reused
+export type CacheKey = string[];
+
+type CacheEntry = {
+  // Key for the input of this cache entry
+  key: CacheKey;
+  // Path to the archive of this cache entry
+  path: string;
+};
+
+// Struct containing information about cache entries on the filesystem.
+// Stored inside the INFO_FILE as JSON.
+type CacheInfo = {
+  // Optional key entry for the contents of the current directory. Used to key the
+  // output present in the outputs folder, where the info file resides inside the output folder.
+  key?: CacheKey;
+  // Optional list of cache archives present in the same directory. Resides in the external
+  // cache location inside one info file for each package.
+  entries?: CacheEntry[];
+};
+
+export class Cache {
+  // Read the current cache state form the filesystem.
+  static async read(options: Options) {
+    const repoPath = relativePath(options.repoRoot, process.cwd());
+    const location = resolvePath(options.cacheDir, repoPath);
+
+    const outputInfo = await readCacheInfo(options.output);
+    const localKey = outputInfo?.key;
+
+    const { entries = [] } = (await readCacheInfo(location)) ?? {};
+    return new Cache(location, entries, localKey);
+  }
+
+  // Generates a key based on the contents of the input paths.
+  // Returns undefined if it's not possible to generate a stable key.
+  static async readInputKey(
+    inputPaths: string[],
+  ): Promise<CacheKey | undefined> {
+    const quotedInputPaths = inputPaths.map(input => `'${input}'`);
+
+    // Make sure we don't have any uncommitted changes to the input, in that case we skip caching.
+    const noChanges = await runCheck(
+      `git diff --quiet HEAD -- ${quotedInputPaths.join(' ')}`,
+    );
+    if (!noChanges) {
+      return undefined;
+    }
+
+    const trees = [];
+    for (const quotedInputPath of quotedInputPaths) {
+      const output = await runPlain(`git ls-tree HEAD ${quotedInputPath}`);
+      const [, , sha] = output.split(/\s+/, 3);
+      trees.push(sha);
+    }
+    return trees;
+  }
+
+  constructor(
+    private readonly location: string,
+    private readonly entries: CacheEntry[] = [],
+    private readonly localKey?: CacheKey,
+  ) {}
+
+  // Query for the presense of cached output for a given key
+  query(key: CacheKey): CacheQueryResult {
+    const { location } = this;
+
+    const archive = async (outputDir: string, maxEntries: number) => {
+      await writeCacheInfo(outputDir, { key });
+
+      const timestamp = new Date().toISOString().replace(/-|:|\..*/g, '');
+      const rand = Math.random()
+        .toString(36)
+        .slice(2, 6);
+      const archiveName = `cache-${timestamp}-${rand}.tgz`;
+      const archivePath = resolvePath(location, archiveName);
+
+      // Read existing entries and prepend the new one
+      const { entries = [] } = (await readCacheInfo(location)) ?? {};
+
+      // Check if there's already aan entry for this key, in that case we just wanna bump it
+      const entryIndex = entries.findIndex(e => compareKeys(e.key, key));
+      if (entryIndex !== -1) {
+        const [existingEntry] = entries.splice(entryIndex, 1);
+        entries.unshift(existingEntry);
+
+        await writeCacheInfo(location, { entries });
+        return;
+      }
+
+      // Create and add new archive to entries
+      await createArchive(archivePath, outputDir);
+      entries.unshift({ key, path: archiveName });
+
+      // Remove old cache entries
+      const removedEntries = entries.splice(maxEntries);
+      for (const entry of removedEntries) {
+        try {
+          await fs.remove(resolvePath(location, entry.path));
+        } catch (error) {
+          process.stderr.write(`failed to remove old cache entry, ${error}\n`);
+        }
+      }
+
+      await writeCacheInfo(location, { entries });
+    };
+
+    if (compareKeys(this.localKey, key)) {
+      return { hit: true, archive };
+    }
+
+    const matchingEntry = this.entries.find(e => compareKeys(e.key, key));
+    if (!matchingEntry) {
+      return { hit: false, archive };
+    }
+
+    return {
+      hit: true,
+      archive,
+      copy: async (outputDir: string) => {
+        const archivePath = resolvePath(location, matchingEntry.path);
+        await extractArchive(archivePath, outputDir);
+      },
+    };
+  }
+}
+
+// Compares to cache keys, returning true if they are both defined and equal
+function compareKeys(a?: CacheKey, b?: CacheKey): boolean {
+  if (!a || !b) {
+    return false;
+  }
+  return a.join(',') === b.join(',');
+}
+
+// Read and parse a cache info file in the given directory
+async function readCacheInfo(
+  parentDir: string,
+): Promise<CacheInfo | undefined> {
+  const infoFile = resolvePath(parentDir, INFO_FILE);
+  const exists = await fs.pathExists(infoFile);
+  if (!exists) {
+    return undefined;
+  }
+
+  const infoData = await fs.readFile(infoFile);
+  const cacheInfo = JSON.parse(infoData.toString('utf8')) as CacheInfo;
+  return cacheInfo;
+}
+
+// Write a cache info file to the given directory
+async function writeCacheInfo(
+  parentDir: string,
+  cacheInfo: CacheInfo,
+): Promise<void> {
+  const infoData = Buffer.from(JSON.stringify(cacheInfo, null, 2), 'utf8');
+  await fs.writeFile(resolvePath(parentDir, INFO_FILE), infoData);
+}

packages/cli/src/commands/build-cache/index.ts

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 { run } from '../../helpers/run';
+import { Cache } from './cache';
+import { parseOptions } from './options';
+
+function print(msg: string) {
+  process.stdout.write(`[build-cache] ${msg}\n`);
+}
+
+/*
+ * The build-cache command is used to make builds a no-op if there are no changes to the package.
+ * It supports both local development where the output directory remains intact, as well as CI
+ * where the output directory is stored in a separate cache dir.
+ */
+export default async (cmd: Command, args: string[]) => {
+  const options = await parseOptions(cmd);
+
+  const key = await Cache.readInputKey(options.inputs);
+  if (!key) {
+    print('input directory is dirty, skipping cache');
+    await run(args[0], args.slice(1));
+    return;
+  }
+
+  const cache = await Cache.read(options);
+
+  const cacheResult = cache.query(key);
+  if (cacheResult.hit) {
+    if (cacheResult.copy) {
+      print('external cache hit, copying archive to output folder');
+      await cacheResult.copy(options.output);
+    } else {
+      print('cache hit, nothing to be done');
+    }
+    return;
+  }
+
+  print('cache miss, need to build');
+
+  await run(args[0], args.slice(1));
+
+  print('caching build output');
+  await cacheResult.archive(options.output, options.maxCacheEntries);
+};

packages/cli/src/commands/build-cache/options.ts

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 { resolve as resolvePath } from 'path';
+import { Command } from 'commander';
+import { runPlain } from '../../helpers/run';
+
+const DEFAULT_MAX_ENTRIES = 10;
+
+export type Options = {
+  inputs: string[];
+  output: string;
+  cacheDir: string;
+  maxCacheEntries: number;
+  repoRoot: string;
+};
+
+export async function parseOptions(cmd: Command): Promise<Options> {
+  const repoRoot = await runPlain('git rev-parse --show-toplevel');
+  const argTransformer = (arg: string) =>
+    resolvePath(arg.replace(/<repoRoot>/g, repoRoot).replace(/'/g, ''));
+
+  const inputs = cmd.input.map(argTransformer) as string[];
+  if (inputs.length === 0) {
+    inputs.push(argTransformer('.'));
+  }
+  const output = argTransformer(cmd.output);
+  const cacheDir = argTransformer(
+    process.env.BACKSTAGE_CACHE_DIR || cmd.cacheDir,
+  );
+  const maxCacheEntries =
+    Number(process.env.BACKSTAGE_CACHE_MAX_ENTRIES) || DEFAULT_MAX_ENTRIES;
+  return { inputs, output, cacheDir, repoRoot, maxCacheEntries };
+}

packages/cli/src/helpers/run.ts

@@ -14,8 +14,15 @@
  * limitations under the License.
  */
 
-import { SpawnOptions, spawn, ChildProcess } from 'child_process';
+import {
+  SpawnOptions,
+  spawn,
+  ChildProcess,
+  exec as execCb,
+} from 'child_process';
 import { ExitCodeError } from './errors';
+import { promisify } from 'util';
+const exec = promisify(execCb);
 
 type SpawnOptionsPartialEnv = Omit<SpawnOptions, 'env'> & {
   env?: Partial<NodeJS.ProcessEnv>;
@@ -43,6 +50,27 @@ export async function run(
   await waitForExit(child, name);
 }
 
+export async function runPlain(cmd: string) {
+  try {
+    const { stdout } = await exec(cmd);
+    return stdout.trim();
+  } catch (error) {
+    if (error.stderr) {
+      process.stderr.write(error.stderr);
+    }
+    throw new ExitCodeError(error.code, cmd);
+  }
+}
+
+export async function runCheck(cmd: string): Promise<boolean> {
+  try {
+    await exec(cmd);
+    return true;
+  } catch (error) {
+    return false;
+  }
+}
+
 export async function waitForExit(
   child: ChildProcess & { exitCode?: number },
   name?: string,

packages/cli/src/index.ts

@@ -19,6 +19,7 @@ import chalk from 'chalk';
 import fs from 'fs';
 import createPluginCommand from './commands/create-plugin/createPlugin';
 import watch from './commands/watch-deps';
+import buildCache from './commands/build-cache';
 import lintCommand from './commands/lint';
 import testCommand from './commands/testCommand';
 import appBuild from './commands/app/build';
@@ -76,6 +77,23 @@ const main = (argv: string[]) => {
     .description('Watch all dependencies while running another command')
     .action(actionHandler(watch));
 
+  program
+    .command('build-cache')
+    .description('Wrap build command with a cache')
+    .option(
+      '--input <dirs>',
+      'List of input directories that invalidate the cache [.]',
+      (value, acc) => acc.concat(value),
+      [],
+    )
+    .option('--output <dir>', 'Output directory to cache', 'dist')
+    .option(
+      '--cache-dir <dir>',
+      'Cache dir',
+      '<repoRoot>/node_modules/.cache/backstage-builds',
+    )
+    .action(actionHandler(buildCache));
+
   program.on('command:*', () => {
     console.log();
     console.log(

packages/cli/templates/default-plugin/package.json.hbs

@@ -6,7 +6,7 @@
   "license": "Apache-2.0",
   "private": true,
   "scripts": {
-    "build": "backstage-cli plugin:build",
+    "build": "backstage-cli build-cache -- backstage-cli plugin:build",
     "lint": "backstage-cli lint",
     "test": "backstage-cli test"
   },

packages/core/package.json

@@ -19,7 +19,7 @@
   "main": "dist/cjs/index.js",
   "types": "dist/cjs/index.d.ts",
   "scripts": {
-    "build": "tsc --outDir dist/cjs --noEmit false --module CommonJS",
+    "build": "backstage-cli build-cache -- tsc --outDir dist/cjs --noEmit false --module CommonJS",
     "lint": "backstage-cli lint",
     "test": "backstage-cli test"
   },

plugins/home-page/package.json

@@ -19,7 +19,7 @@
     "react-dom": "^16.12.0"
   },
   "scripts": {
-    "build": "backstage-cli plugin:build",
+    "build": "backstage-cli build-cache -- backstage-cli plugin:build",
     "lint": "backstage-cli lint",
     "test": "backstage-cli test"
   },

plugins/welcome/package.json

@@ -6,7 +6,7 @@
   "license": "Apache-2.0",
   "private": true,
   "scripts": {
-    "build": "backstage-cli plugin:build",
+    "build": "backstage-cli build-cache -- backstage-cli plugin:build",
     "lint": "backstage-cli lint",
     "test": "backstage-cli test"
   },

yarn.lock

@@ -3612,6 +3612,13 @@
   resolved "https://registry.npmjs.org/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"
   integrity sha512-tHq6qdbT9U1IRSGf14CL0pUlULksvY9OZ+5eEgl1N7t+OA3tGvNpxJCzuKQlsNgCVwbAs670L1vcVQi8j9HjnA==
 
+"@types/minipass@*":
+  version "2.2.0"
+  resolved "https://registry.npmjs.org/@types/minipass/-/minipass-2.2.0.tgz#51ad404e8eb1fa961f75ec61205796807b6f9651"
+  integrity sha512-wuzZksN4w4kyfoOv/dlpov4NOunwutLA/q7uc00xU02ZyUY+aoM5PWIXEKBMnm0NHd4a+N71BMjq+x7+2Af1fg==
+  dependencies:
+    "@types/node" "*"
+
 "@types/node@*", "@types/node@>= 8", "@types/node@^13.7.2":
   version "13.9.2"
   resolved "https://registry.npmjs.org/@types/node/-/node-13.9.2.tgz#ace1880c03594cc3e80206d96847157d8e7fa349"
@@ -3776,6 +3783,14 @@
   resolved "https://registry.npmjs.org/@types/tapable/-/tapable-1.0.5.tgz#9adbc12950582aa65ead76bffdf39fe0c27a3c02"
   integrity sha512-/gG2M/Imw7cQFp8PGvz/SwocNrmKFjFsm5Pb8HdbHkZ1K8pmuPzOX4VeVoiEecFCVf4CsN1r3/BRvx+6sNqwtQ==
 
+"@types/tar@^4.0.3":
+  version "4.0.3"
+  resolved "https://registry.npmjs.org/@types/tar/-/tar-4.0.3.tgz#e2cce0b8ff4f285293243f5971bd7199176ac489"
+  integrity sha512-Z7AVMMlkI8NTWF0qGhC4QIX0zkV/+y0J8x7b/RsHrN0310+YNjoJd8UrApCiGBCWtKjxS9QhNqLi2UJNToh5hA==
+  dependencies:
+    "@types/minipass" "*"
+    "@types/node" "*"
+
 "@types/testing-library__cypress@^5.0.3":
   version "5.0.3"
   resolved "https://registry.npmjs.org/@types/testing-library__cypress/-/testing-library__cypress-5.0.3.tgz#94969b7c1eea96e09d8e023a1d225590fa75a1fe"
@@ -5795,7 +5810,7 @@ chokidar@^3.2.2, chokidar@^3.3.0, chokidar@^3.3.1:
   optionalDependencies:
     fsevents "~2.1.2"
 
-chownr@^1.1.1, chownr@^1.1.2, chownr@^1.1.4:
+chownr@^1.1.1, chownr@^1.1.2, chownr@^1.1.3, chownr@^1.1.4:
   version "1.1.4"
   resolved "https://registry.npmjs.org/chownr/-/chownr-1.1.4.tgz#6fc9d7b42d32a583596337666e7d08084da2cc6b"
   integrity sha512-jJ0bqzaylmJtVnNgzTeSOs8DPavpbYgEr/b0YL8/2GO3xJEhInFmhKMUnEJQjZumK7KXGFhUy89PrsJWlakBVg==
@@ -13039,6 +13054,14 @@ minizlib@^1.2.1:
   dependencies:
     minipass "^2.9.0"
 
+minizlib@^2.1.0:
+  version "2.1.0"
+  resolved "https://registry.npmjs.org/minizlib/-/minizlib-2.1.0.tgz#fd52c645301ef09a63a2c209697c294c6ce02cf3"
+  integrity sha512-EzTZN/fjSvifSX0SlqUERCN39o6T40AMarPbv0MrarSFtIITCBh7bi+dU8nxGFHuqs9jdIAeoYoKuQAAASsPPA==
+  dependencies:
+    minipass "^3.0.0"
+    yallist "^4.0.0"
+
 mississippi@^3.0.0:
   version "3.0.0"
   resolved "https://registry.npmjs.org/mississippi/-/mississippi-3.0.0.tgz#ea0a3291f97e0b5e8776b363d5f0a12d94c67022"
@@ -13078,7 +13101,7 @@ mkdirp-promise@^5.0.1:
   dependencies:
     mkdirp "*"
 
-mkdirp@*:
+mkdirp@*, mkdirp@^1.0.3:
   version "1.0.3"
   resolved "https://registry.npmjs.org/mkdirp/-/mkdirp-1.0.3.tgz#4cf2e30ad45959dddea53ad97d518b6c8205e1ea"
   integrity sha512-6uCP4Qc0sWsgMLy1EOqqS/3rjDHOEnsStVr/4vtAIK2Y5i2kA7lFFejYrpIyiN9w0pYf4ckeCYT9f1r1P9KX5g==
@@ -18083,6 +18106,18 @@ tar@^4.4.10, tar@^4.4.12, tar@^4.4.13, tar@^4.4.8:
     safe-buffer "^5.1.2"
     yallist "^3.0.3"
 
+tar@^6.0.1:
+  version "6.0.1"
+  resolved "https://registry.npmjs.org/tar/-/tar-6.0.1.tgz#7b3bd6c313cb6e0153770108f8d70ac298607efa"
+  integrity sha512-bKhKrrz2FJJj5s7wynxy/fyxpE0CmCjmOQ1KV4KkgXFWOgoIT/NbTMnB1n+LFNrNk0SSBVGGxcK5AGsyC+pW5Q==
+  dependencies:
+    chownr "^1.1.3"
+    fs-minipass "^2.0.0"
+    minipass "^3.0.0"
+    minizlib "^2.1.0"
+    mkdirp "^1.0.3"
+    yallist "^4.0.0"
+
 telejson@^3.2.0:
   version "3.3.0"
   resolved "https://registry.npmjs.org/telejson/-/telejson-3.3.0.tgz#6d814f3c0d254d5c4770085aad063e266b56ad03"