CI: add support for getting ccache cache from S3

Add support for getting ccache cache from S3.
ccache is archieved in a tar and downloaded from S3 Cloud Storage.

For push events, ccache is then uplodaed back to S3 to refresh and have
a ccache cache always fresh.

An additional workflow is added to upload files to an S3 Cloud Storage
from artifacts uplodaed to github. The minio tool is used to upload
files to S3.

If the ccache can't be downloaded from s3, we fallback to github cache
system.

Also limit s3 upload to the openwrt repository since external fork won't
have (obviously) the required secrtes to upload data to the S3 Cloud
Storage.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

4 files changed, 124 insertions, 3 deletions

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 95d19f4c4e0..efaf7594033 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -60,6 +60,8 @@ on:
       ccache_type:
         type: string
         default: kernel
+      upload_ccache_cache:
+        type: boolean
 
 permissions:
   contents: read
@@ -232,6 +234,20 @@ jobs:
           echo "TOOLCHAIN_FILE=$TOOLCHAIN_FILE" >> "$GITHUB_ENV"
           echo "TOOLCHAIN_PATH=$TOOLCHAIN_PATH" >> "$GITHUB_ENV"
 
+      - name: Download and extract ccache cache from s3
+        id: restore-ccache-cache-s3
+        if: inputs.use_ccache_cache == true
+        working-directory: openwrt
+        run: |
+          ENDPOINT=https://storage.googleapis.com
+          BUCKET=openwrt-ci-cache
+          CCACHE_TAR=ccache-${{ inputs.ccache_type }}-${{ inputs.target }}-${{ inputs.subtarget }}.tar
+
+          if curl -o /dev/null -s --head --fail $ENDPOINT/$BUCKET/$CCACHE_TAR; then
+            wget -O - $ENDPOINT/$BUCKET/$CCACHE_TAR | tar -xf -
+            echo "cache-hit=true" >> $GITHUB_OUTPUT
+          fi
+
       - name: Fix permission
         run: |
           chown -R buildbot:buildbot openwrt
@@ -256,7 +272,7 @@ jobs:
 
       - name: Restore ccache cache
         id: restore-ccache-cache
-        if: inputs.use_ccache_cache == true
+        if: inputs.use_ccache_cache == true && steps.restore-ccache-cache-s3.outputs.cache-hit != 'true'
         uses: actions/cache/restore@v3
         with:
           path: openwrt/.ccache
@@ -498,7 +514,8 @@ jobs:
           path: "openwrt/logs"
 
       - name: Delete already present ccache cache
-        if: steps.restore-ccache-cache.outputs.cache-hit == 'true' && inputs.use_ccache_cache == true  && github.event_name == 'push'
+        if: steps.restore-ccache-cache.outputs.cache-hit == 'true' && inputs.use_ccache_cache == true  &&
+          github.event_name == 'push' && steps.restore-ccache-cache-s3.outputs.cache-hit != 'true'
         uses: octokit/request-action@v2.x
         with:
           route: DELETE /repos/{repository}/actions/caches?key={key}
@@ -508,12 +525,29 @@ jobs:
           INPUT_KEY: ${{ steps.restore-ccache-cache.outputs.cache-primary-key }}
 
       - name: Save ccache cache
-        if: inputs.use_ccache_cache == true && github.event_name == 'push'
+        if: inputs.use_ccache_cache == true && github.event_name == 'push' &&
+          steps.restore-ccache-cache-s3.outputs.cache-hit != 'true'
         uses: actions/cache/save@v3
         with:
           path: openwrt/.ccache
           key: ${{ steps.restore-ccache-cache.outputs.cache-primary-key }}
 
+      - name: Archive ccache
+        if: inputs.use_ccache_cache == true  && github.event_name == 'push' &&
+          inputs.upload_ccache_cache == true
+        shell: su buildbot -c "sh -e {0}"
+        working-directory: openwrt
+        run: tar -cf ccache-${{ inputs.ccache_type }}-${{ inputs.target }}-${{ inputs.subtarget }}.tar .ccache
+
+      - name: Upload ccache cache
+        if: inputs.use_ccache_cache == true && github.event_name == 'push' &&
+          inputs.upload_ccache_cache == true
+        uses: actions/upload-artifact@v3
+        with:
+          name: ${{ inputs.target }}-${{ inputs.subtarget }}-ccache-cache
+          path: openwrt/ccache-${{ inputs.ccache_type }}-${{ inputs.target }}-${{ inputs.subtarget }}.tar
+          retention-days: 1
+
       - name: Find external toolchain name
         id: get-toolchain-name
         if: inputs.upload_external_toolchain == true
diff --git a/.github/workflows/kernel.yml b/.github/workflows/kernel.yml
index d9ab8581c9b..5f18a39c553 100644
--- a/.github/workflows/kernel.yml
+++ b/.github/workflows/kernel.yml
@@ -117,6 +117,7 @@ jobs:
       subtarget: ${{ matrix.subtarget }}
       build_kernel: true
       build_all_kmods: true
+      upload_ccache_cache: ${{ github.repository_owner == 'openwrt' }}
 
   check-kernel-patches:
     name: Check Kernel patches
@@ -133,3 +134,20 @@ jobs:
       target: ${{ matrix.target }}
       subtarget: ${{ matrix.subtarget }}
 
+  upload-ccache-cache-in-s3:
+    if: github.event_name == 'push' && github.repository_owner == 'openwrt'
+    name: Upload ccache cache to s3
+    needs: [determine_targets, build]
+    strategy:
+       fail-fast: False
+       matrix:
+         include: ${{fromJson(needs.determine_targets.outputs.targets_subtargets)}}
+    secrets:
+      s3_access_key: ${{ secrets.GCS_S3_ACCESS_KEY }}
+      s3_secret_key: ${{ secrets.GCS_S3_SECRET_KEY }}
+    uses: ./.github/workflows/upload-file-s3.yml
+    with:
+      endpoint: https://storage.googleapis.com
+      bucket: openwrt-ci-cache
+      download_id: ${{ matrix.target }}-${{ matrix.subtarget }}-ccache-cache
+      filename: ccache-kernel-${{ matrix.target }}-${{ matrix.subtarget }}.tar
diff --git a/.github/workflows/packages.yml b/.github/workflows/packages.yml
index 58bbcd01311..fe2898cacdb 100644
--- a/.github/workflows/packages.yml
+++ b/.github/workflows/packages.yml
@@ -54,4 +54,27 @@ jobs:
       build_all_modules: true
       build_full: true
       ccache_type: packages
+      upload_ccache_cache: ${{ github.repository_owner == 'openwrt' }}
+
+  upload-ccache-cache-in-s3:
+    if: github.event_name == 'push' && github.repository_owner == 'openwrt'
+    name: Upload ccache cache to s3
+    needs: build
+    strategy:
+       fail-fast: False
+       matrix:
+        include:
+          - target: malta
+            subtarget: be
+          - target: x86
+            subtarget: 64
+    secrets:
+      s3_access_key: ${{ secrets.GCS_S3_ACCESS_KEY }}
+      s3_secret_key: ${{ secrets.GCS_S3_SECRET_KEY }}
+    uses: ./.github/workflows/upload-file-s3.yml
+    with:
+      endpoint: https://storage.googleapis.com
+      bucket: openwrt-ci-cache
+      download_id: ${{ matrix.target }}-${{ matrix.subtarget }}-ccache-cache
+      filename: ccache-packages-${{ matrix.target }}-${{ matrix.subtarget }}.tar
 
diff --git a/.github/workflows/upload-file-s3.yml b/.github/workflows/upload-file-s3.yml
new file mode 100644
index 00000000000..6bcb172468d
--- /dev/null
+++ b/.github/workflows/upload-file-s3.yml
@@ -0,0 +1,46 @@
+name: Upload File to S3
+
+on:
+  workflow_call:
+    secrets:
+      s3_access_key:
+      s3_secret_key:
+    inputs:
+      endpoint:
+        required: true
+        type: string
+      bucket:
+        required: true
+        type: string
+      download_id:
+        required: true
+        type: string
+      filename:
+        required: true
+        type: string
+
+jobs:
+  upload-file-in-s3:
+    name: Upload file in S3
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Install minio
+        run: |
+          curl https://dl.min.io/client/mc/release/linux-amd64/mc \
+            --create-dirs \
+            -o $GITHUB_WORKSPACE/minio-binaries/mc
+
+          chmod +x $GITHUB_WORKSPACE/minio-binaries/mc
+          echo $GITHUB_WORKSPACE/minio-binaries/ >> $GITHUB_PATH
+
+      - name: Setup minio
+        run: mc alias set s3 ${{ inputs.endpoint }} ${{ secrets.s3_access_key }} ${{ secrets.s3_secret_key }}
+
+      - name: Download file
+        uses: actions/download-artifact@v3
+        with:
+          name: ${{ inputs.download_id }}
+
+      - name: Upload file to s3
+        run: mc cp ${{ inputs.filename }} s3/${{ inputs.bucket }}/