feat: optimize Go Mod cache (#15007)

* fix: go mod caching

* fix: only cache modules

.github/actions/setup-go/action.yml

@@ -13,6 +13,11 @@ inputs:
   go-module-file:
     description: Set where the go module file is located at
     default: "go.sum"
+  restore-module-cache-only:
+    description: |
+      Only restore the module cache, don't automatically update it.
+      Leave the updating to go-mod-cache.yml.
+    default: "true"
 
 runs:
   using: composite
@@ -40,14 +45,33 @@ runs:
       shell: bash
       run: echo "path=./${{ inputs.go-module-file }}" >> $GITHUB_OUTPUT
 
+    # By default, restore the cache only.
+    # If multiple jobs call actions/cache, then only one will get priority to create upon a cache miss.
+    # We will only restore the cache by default (by calling actions/cache/restore) and let the
+    # `go-mod-cache.yml` workflow handle the creation.
+    - uses: actions/cache/restore@v4.1.1
+      if: ${{ inputs.restore-module-cache-only == 'true' }}
+      name: Cache Go Modules
+      with:
+        path: |
+          ${{ steps.go-cache-dir.outputs.gomodcache }}
+        # The lifetime of go modules is much higher than the build outputs, so we increase cache efficiency
+        # here by not having the primary key contain the branch name
+        key: ${{ runner.os }}-gomod-${{ inputs.cache-version }}-${{ hashFiles(steps.go-module-path.outputs.path) }}
+        restore-keys: |
+          ${{ runner.os }}-gomod-${{ inputs.cache-version }}-
+
+    # If this is called, then it will create the cache entry upon a cache miss.
+    # The cache is created after a cache miss, and after job completes successfully.
     - uses: actions/cache@v4.1.1
+      if: ${{ inputs.restore-module-cache-only != 'true' }}
       name: Cache Go Modules
       with:
         path: |
           ${{ steps.go-cache-dir.outputs.gomodcache }}
         # The lifetime of go modules is much higher than the build outputs, so we increase cache efficiency
         # here by not having the primary key contain the branch name
-        key: ${{ runner.os }}-gomod-${{ inputs.cache-version }}-${{ hashFiles(steps.go-module-path.output.path) }}
+        key: ${{ runner.os }}-gomod-${{ inputs.cache-version }}-${{ hashFiles(steps.go-module-path.outputs.path) }}
         restore-keys: |
           ${{ runner.os }}-gomod-${{ inputs.cache-version }}-
 

.github/workflows/ci-scripts.yml

@@ -25,9 +25,6 @@ jobs:
           go-directory: core/scripts
           go-version-file: core/scripts/go.mod
           go-module-file: core/scripts/go.sum
-          gc-basic-auth: ${{ secrets.GRAFANA_INTERNAL_BASIC_AUTH }}
-          gc-host: ${{ secrets.GRAFANA_INTERNAL_HOST }}
-          gc-org-id: ${{ secrets.GRAFANA_INTERNAL_TENANT_ID }}
 
   test-scripts:
     runs-on: ubuntu-latest

.github/workflows/go-mod-cache.yml

@@ -0,0 +1,43 @@
+name: Go Module Cache
+
+# This workflow is responsible for updating the Go Module Cache.
+# It will maintain the cache: linux-gomod-1-<hash>
+# All other workflows should only restore this cache.
+
+# This workflow is useful because it will:
+# 1. Create the cache if it doesn't exist
+#   - This can be a problem when multiple jobs load the same cache.
+#     Only one will get priority to create the cache.
+# 2. Should not fail, therefore creating a cache
+#   - When a Job errors/fails it will not upload a new cache.
+#     So when test/build jobs are responsible for creating the new cache,
+#     they can fail causing cache misses on subsequent runs. Even though
+#     the dependencies haven't changed.
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+on:
+  push:
+    branches:
+      - develop
+  pull_request:
+
+jobs:
+  go-cache:
+    name: Go Cache
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout the repo
+        uses: actions/checkout@v4.2.1
+
+      - name: Setup Go
+        uses: ./.github/actions/setup-go
+        with:
+          only-modules: "true"
+          restore-module-cache-only: "false"
+
+      - name: Install Dependencies
+        shell: bash
+        run:  go mod download all