feat: adding retention policy (ApeWorX#2247)

.github/workflows/build.yaml

@@ -39,7 +39,6 @@ jobs:
 
       - name: Show tags
         run: |
-          git tag
           echo ${{ steps.meta.outputs.tags }}
 
       - name: Extract version from tag
@@ -77,3 +76,51 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           build-args: |
             SLIM_IMAGE=${{ steps.meta.outputs.tags }}-slim
+
+      - name: Fetch all tags and store them
+        run: |
+          # List all tags
+          tags=$(git tag -l)
+          echo "All tags:"
+          echo "$tags"
+
+          # Save tags in an environment variable for later use
+          echo "ALL_TAGS=$(echo $tags | tr '\n' ' ')" >> $GITHUB_ENV
+
+      - name: Retain last two minor versions
+        run: |
+          # Fetch all tags in the format X.Y.Z
+          echo "Using stored tags..."
+          all_tags="${{ env.ALL_TAGS }}"
+          echo "All tags:"
+          echo "$all_tags"
+
+          # Extract the minor versions (X.Y) from tags in the format vX.X.X
+          latest_two_minors=$(echo "$all_tags" | tr ' ' '\n' | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+$' | sed -E 's/^v([0-9]+\.[0-9]+)\.[0-9]+$/\1/' | uniq | tail -n 2)
+          echo "Last two minor versions:"
+          echo "$latest_two_minors"
+
+          keep_tags=""
+          for minor in $latest_two_minors; do
+            echo "Processing minor version: $minor"
+            patches=$(echo "$all_tags" | tr ' ' '\n' | grep "^v$minor\.")
+            echo "Latest patch for $minor: $patches"
+            keep_tags="$keep_tags $patches"
+          done
+
+          # Store the tags in the environment variable
+          keep_tags=$(echo $keep_tags | tr ' ' '\n' | paste -sd ',' -)
+          echo "Tags to keep: $keep_tags"
+          echo "keep_tags=$keep_tags" >> $GITHUB_ENV
+          echo "keep_tags=$keep_tags"
+
+      - name: Run container retention policy
+        if: github.ref == 'refs/heads/main'
+        uses: snok/[email protected]
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          keep-tag-names: |
+            stable
+            latest
+            ${{ env.keep_tags }}
+