Manually prune old entries from Go cache

The Go cache has fixed trim settings. It updates mtimes hourly and trims
daily, deleting anything older than five days. This is too conservative
for CI caches. We only want to retain caches used in the current run.

We can achieve this by setting the mtime of all cache files to a time
between one hour and five days ago. After the build, all used cache
entries will have a newer mtime. Everything else can be trimmed.

Signed-off-by: Tom Wieczorek <[email protected]>
(cherry picked from commit 5d8587e)

Author: twz123

.github/workflows/build-k0s.yml

@@ -69,6 +69,7 @@ jobs:
             pkg/assets/zz_generated_offsets_${{ inputs.target-os }}.go
 
       - name: "Cache :: GOCACHE"
+        id: cache-gocache
         uses: actions/cache@v4
         with:
           key: build-k0s-${{ inputs.target-os }}-${{ inputs.target-arch }}-gocache-${{ github.ref_name }}-${{ github.sha }}
@@ -77,6 +78,12 @@ jobs:
           path: |
             build/cache/go/build
 
+      - name: "Cache :: GOCACHE :: Prepare"
+        if: steps.cache-gocache.outputs.cache-hit
+        run: |
+          touch -t "$(TZ=UTC+24 date +%Y%m%d%H%M.%S)" build/cache/_cache_sentinel
+          find build/cache/go/build -type f \( -name '*-a' -o -name '*-d' \) -exec touch -r build/cache/_cache_sentinel {} +
+
       - name: "Cache :: GOMODCACHE"
         uses: actions/cache@v4
         with:
@@ -119,3 +126,8 @@ jobs:
         with:
           name: ipv6-test-image-list-${{ inputs.target-os }}-${{ inputs.target-arch }}
           path: ipv6-test-images.txt
+
+      - name: "Cache :: GOCACHE :: Trim"
+        if: steps.cache-gocache.outputs.cache-hit
+        run: |
+          find build/cache/go/build -type f \( -name '*-a' -o -name '*-d' \) -not -newer build/cache/_cache_sentinel -delete

.github/workflows/go.yml

@@ -209,6 +209,7 @@ jobs:
           cache: false
 
       - name: Cache GOCACHE
+        id: cache-gocache
         uses: actions/cache@v4
         with:
           key: unittests-k0s-${{ matrix.name }}-gocache-${{ github.ref_name }}-${{ github.sha }}
@@ -225,7 +226,21 @@ jobs:
           enableCrossOsArchive: true
 
       - name: Run unit tests
-        run: make check-unit $UNITTEST_EXTRA_ARGS
+        env:
+          CACHE_HIT_GOCACHE: "${{ steps.cache-gocache.outputs.cache-hit }}"
+        run: |
+          if [ -n "$CACHE_HIT_GOCACHE" ]; then
+            echo Preparing Go cache
+            touch -t "$(TZ=UTC+24 date +%Y%m%d%H%M.%S)" build/cache/_cache_sentinel
+            find build/cache/go/build -type f \( -name '*-a' -o -name '*-d' \) -exec touch -r build/cache/_cache_sentinel {} +
+          fi
+
+          make check-unit $UNITTEST_EXTRA_ARGS
+
+          if [ -n "$CACHE_HIT_GOCACHE" ]; then
+            echo Trimming Go cache
+            find build/cache/go/build -type f \( -name '*-a' -o -name '*-d' \) -not -newer build/cache/_cache_sentinel -delete
+          fi
 
   smoketests:
     strategy:
@@ -317,6 +332,7 @@ jobs:
             embedded-bins/Makefile.variables
 
       - name: Cache GOCACHE
+        id: cache-gocache
         uses: actions/cache@v4
         with:
           key: ${{ runner.os }}-smoketest-arm-gocache-arm-${{ github.ref_name }}-${{ github.sha }}
@@ -325,6 +341,12 @@ jobs:
           path: |
             build/cache/go/build
 
+      - name: Cache GOCACHE - Prepare
+        if: steps.cache-gocache.outputs.cache-hit
+        run: |
+          touch -t "$(TZ=UTC+24 date +%Y%m%d%H%M.%S)" build/cache/_cache_sentinel
+          find build/cache/go/build -type f \( -name '*-a' -o -name '*-d' \) -exec touch -r build/cache/_cache_sentinel {} +
+
       - name: Cache GOMODCACHE
         uses: actions/cache@v4
         with:
@@ -369,6 +391,11 @@ jobs:
           name: airgap-image-bundle-linux-arm.tar
           path: airgap-image-bundle-linux-arm.tar
 
+      - name: Cache GOCACHE - Trim
+        if: steps.cache-gocache.outputs.cache-hit
+        run: |
+          find build/cache/go/build -type f \( -name '*-a' -o -name '*-d' \) -not -newer build/cache/_cache_sentinel -delete
+
   # TODO We probably want to separate the smoketest into a separate callable workflow which we can call from the build step
   # This way we could actually fully parallelize the build and smoketest steps. Currently we are limited by the fact that
   # smoke-test step only start after both arm and armv7 builds have finished.

.github/workflows/lint.yaml

@@ -68,6 +68,7 @@ jobs:
           cache: false
 
       - name: "Cache :: golangci-lint"
+        id: cache-golangci
         uses: actions/cache@v4
         with:
           key: lint-${{ matrix.target-os }}-amd64-golangci-${{ github.ref_name }}-${{ github.sha }}
@@ -86,7 +87,21 @@ jobs:
           enableCrossOsArchive: true
 
       - name: Run linter
-        run: make lint-go $MAKE_EXTRA_ARGS
+        env:
+          CACHE_HIT_GOLANGCI: "${{ steps.cache-golangci.outputs.cache-hit }}"
+        run: |
+          if [ -n "$CACHE_HIT_GOLANGCI" ]; then
+            echo Preparing golangci-lint cache
+            touch -t "$(TZ=UTC+24 date +%Y%m%d%H%M.%S)" build/cache/_cache_sentinel
+            find build/cache/go/build build/cache/golangci-lint -type f \( -name '*-a' -o -name '*-d' \) -exec touch -r build/cache/_cache_sentinel {} +
+          fi
+
+          make lint-go $MAKE_EXTRA_ARGS
+
+          if [ -n "$CACHE_HIT_GOLANGCI" ]; then
+            echo Trimming golangci-lint cache
+            find build/cache/go/build build/cache/golangci-lint -type f \( -name '*-a' -o -name '*-d' \) -not -newer build/cache/_cache_sentinel -delete
+          fi
 
   lint-codegen:
     name: Lint generated code