Note_Tech

All technological notes.

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GitHub Actions: Caching

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• GitHub Actions: Caching
  • Caching
    • Lab: Caching
    • Lab: Caching across Jobs

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Caching

• Caching
  • ref: https://docs.github.com/en/actions/reference/workflows-and-actions/dependency-caching
  • Speed up workflow runs by caching stable files
  • store files and later retrieve them based on a key.
• Workflows can access the cache from their branch or from the default branch.
• Use case:
  • Cache dependencies to speed up execution by avoiding always downloading and installing them.
• Workflow run starts -> Execute cache step -> Cache matching key?
  • yes: Restore cache
  • No: Install dependencies
  • -> Execute lint & testing
• retained for a maximum of 7 days since they were last accessed.

---

• example:

steps:
  - uses: actions/cache@v3
    id: cache
    with:
      path: node_modules
      key: $

   - name: Install dependencies
     if: steps.cache.outputs.cache-hit != 'true'
     run: npm ci

   - name: Lint & test
     run: |
      npm run lint
      npm run test

---

Lab: Caching

name: 13 - caching

on:
  workflow_dispatch:
    inputs:
      use-cache:
        type: boolean
        default: true
        description: Whether to use cache

jobs:
  build:
    runs-on: ubuntu-latest
    defaults:
      run:
        working-directory: react-app
    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: setup node
        uses: actions/setup-node@v6
        with:
          node-version: "24.x"

      - name: Download dependencies
        id: cache-deps
        if: $
        uses: actions/cache@v5
        with:
          path: react-app/node_modules
          key: deps-node-modules-$

      - name: Install dependencies
        if: steps.cache-deps.outputs.cache-hit != 'true'
        run: npm ci

      - name: Testing
        run: npm run test

      - name: Building
        run: npm run build

      - name: Deploying
        run: echo "Deploying to nonprod"

from 43s -> 26s key log: no Caching

• Post Download dependencies Sent 44832387 of 44832387 (100.0%), 46.8 MBs/sec Cache saved with key: deps-node-modules-4e51da629d104b02c6198499472f35027b1d0783d5450e91e6cc8e30af96d8c2

Caching

• Download dependencies Cache hit for: deps-node-modules-4e51da629d104b02c6198499472f35027b1d0783d5450e91e6cc8e30af96d8c2 Received 44832387 of 44832387 (100.0%), 125.0 MBs/sec Cache Size: ~43 MB (44832387 B) Cache restored successfully Cache restored from key: deps-node-modules-4e51da629d104b02c6198499472f35027b1d0783d5450e91e6cc8e30af96d8c2
• Install dependencies: skiped

---

Lab: Caching across Jobs

• pre-install job:
  • build and cache
  • Generate the cache key and output
• build job:
  • hit cache key and download

name: 13 - caching across jobs

on:
  workflow_dispatch:
    inputs:
      use-cache:
        type: boolean
        default: true
        description: Whether to use cache

jobs:
  pre-install:
    runs-on: ubuntu-latest
    defaults:
      run:
        working-directory: react-app
    outputs:
      deps-cache-key: $
    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: setup node
        uses: actions/setup-node@v6
        with:
          node-version: "24.x"

      - name: Generate cache key
        id: cache-key
        run: |
          echo "CACHE_KEY=deps-node-modules-$" >> "$GITHUB_OUTPUT"

      - name: Download dependencies
        id: cache-deps
        if: $
        uses: actions/cache@v5
        with:
          path: react-app/node_modules
          key: $

      - name: Install dependencies
        if: steps.cache-deps.outputs.cache-hit != 'true'
        run: npm ci

  build:
    runs-on: ubuntu-latest
    needs: pre-install
    defaults:
      run:
        working-directory: react-app
    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: setup node
        uses: actions/setup-node@v6
        with:
          node-version: "24.x"

      - name: Download dependencies
        id: cache-deps
        if: $
        uses: actions/cache@v5
        with:
          path: react-app/node_modules
          key: $

      - name: Install dependencies
        if: steps.cache-deps.outputs.cache-hit != 'true'
        run: npm ci

      - name: Testing
        run: npm run test

      - name: Building
        run: npm run build

      - name: Deploying
        run: echo "Deploying to nonprod"

• Extensions
  • one caching can be shared with multiple jobs