Cache

See the actions/cache page in the Actions marketplace.

Note that it is recommended to have a lock file for this flow, though you don’t have to such as a the Python case.

General usage

• main.yml

    steps:
      - name: Cache
        uses: actions/cache@v2.0.0
        with:
  
        # A list of files, directories, and wildcard patterns to cache and restore
        path:
  
        # An explicit key for restoring and saving the cache
        key:
  
        # An ordered list of keys to use for restoring the cache if no cache hit occurred for key
        restore-keys: # optional
  

Note restore-keys is usually set as a multi-line YAML string - of one or two lines. Not an array.

Samples

Based on the Examples in the action’s docs.

NPM

From the Node - NPM examples.

See NPM workflow recipes.

Built-in

Use the cache option on setup-node action:

• main.yml

    steps:
      - name: Set up Node.js
        uses: actions/setup-node@v2
        with:
          node-version: '14.x'
          cache: 'npm'
  
      - name: Install dependencies
        run: npm install
  

Use cache action

The cache location will be ~/.npm on Unix/Posix. See NPM cache in the docs NPM docs.

• main.yml

    steps:
      - name: Get cached dependencies
        uses: actions/cache@v2
        with:
          path: ~/.npm
          key: ${{ runner.os }}-node-${{ hashFiles('**/package-lock.json') }}
          restore-keys: |
            ${{ runner.os }}-node-
  
      - name: Install dependencies
        run: npm install
  

Make sure to use npm install and not npm ci - the latter will delete any node_modules directory that was retrieved from the cache and so will delete the point of using this Cache Action.

Use NPM config

If using npm config to retrieve the cache directory, ensure you run actions/setup-node first to ensure your npm version is correct.

For a code sample, see example.

Yarn

From the Node - Yarn example.

This has an extra step compared with the NPM flow - it uses the yarn cache dir command to dynamically lookup a value like ~/.cache/yarn/v6.

• main.yml

    steps:
      - name: Get Yarn cache directory
        id: yarn-cache-dir
        run: echo "::set-output name=dir::$(yarn cache dir)"
  
      - uses: actions/cache@v2
        id: yarn-cache
        with:
          path: ${{ steps.yarn-cache-dir.outputs.dir }}
          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
          restore-keys: |
            ${{ runner.os }}-yarn-
  
      - name: Install dependencies
        run: yarn install --frozen-lockfile
  

Yarn help on the use of the flag:

• --frozen-lockfile - don’t generate a lockfile and fail if an update is needed

Python

From Python - Pip example.

A simple example.

• main.yml

    steps:
      - uses: actions/cache@v2
        with:
          path: ~/.cache/pip
          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
          restore-keys: |
            ${{ runner.os }}-pip-
  

Ruby

• You get cache already when using setup-ruby action.
• Or you can use cache for more control.

See Ruby workflow recipes.