Add support to compare platform variants (#29)

Add support to optionally compare image platform variants. Eg. linux/arm64 is equal to linux/arm64/v8 and both are heavily used on docker images.

Author: clowa

.github/workflows/test.yml

@@ -11,6 +11,9 @@ env:
   DEBUG: ${{ secrets.ACTIONS_STEP_DEBUG }}
 
 jobs:
+  #####################################
+  # Singe platform tests
+
   test1:
     name: Test Update Needed
     runs-on: ubuntu-22.04
@@ -52,6 +55,26 @@ jobs:
           fi
 
   test3:
+    name: Test single platform
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+      - name: Test Action
+        id: test
+        uses: ./
+        with:
+          base-image: alpine:3.17.1
+          image: lucacome/alpine-amd64
+      - name: Get Test Output
+        run: echo "Workflow Docker Image ${{ steps.test.outputs.needs-updating }}"
+      - name: Check value
+        run: |
+          if [[ "${{ steps.test.outputs.needs-updating }}" != "false" ]]; then
+            exit 1
+          fi
+
+  test4:
     name: Test Update Needed on ARM64
     runs-on: ubuntu-22.04
     steps:
@@ -72,7 +95,10 @@ jobs:
             exit 1
           fi
 
-  test4:
+  #####################################
+  # Test with multiple platforms
+
+  test5:
     name: Test Update Needed on multiple platforms
     runs-on: ubuntu-22.04
     steps:
@@ -93,7 +119,7 @@ jobs:
             exit 1
           fi
 
-  test5:
+  test6:
     name: Test Update Not Needed on multiple platforms
     runs-on: ubuntu-22.04
     steps:
@@ -113,9 +139,11 @@ jobs:
           if [[ "${{ steps.test.outputs.needs-updating }}" != "false" ]]; then
             exit 1
           fi
+  #####################################
+  # Test with platform variants
 
-  test6:
-    name: Test single platform
+  test7:
+    name: Test Update Needed on multiple platforms with variants
     runs-on: ubuntu-22.04
     steps:
       - name: Checkout Repository
@@ -124,8 +152,30 @@ jobs:
         id: test
         uses: ./
         with:
-          base-image: alpine:3.17.1
-          image: lucacome/alpine-amd64
+          base-image: alpine:latest
+          image: golang:1.14.15-alpine3.13
+          platforms: linux/arm64/v8,linux/arm/v7,linux/amd64
+      - name: Get Test Output
+        run: echo "Workflow Docker Image ${{ steps.test.outputs.needs-updating }}"
+      - name: Check value
+        run: |
+          if [[ "${{ steps.test.outputs.needs-updating }}" != "true" ]]; then
+            exit 1
+          fi
+
+  test8:
+    name: Test Update Not Needed on multiple platforms with variants
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+      - name: Test Action
+        id: test
+        uses: ./
+        with:
+          base-image: alpine:3.17.2
+          image: alpine:3.17.2
+          platforms: linux/arm64/v8,linux/arm/v7,linux/amd64
       - name: Get Test Output
         run: echo "Workflow Docker Image ${{ steps.test.outputs.needs-updating }}"
       - name: Check value

docker.sh

@@ -28,14 +28,16 @@ get_manifests() {
     fi
 
     headers=$(cat headers | awk -F ': ' '{sub(/\r/,"\n",$2); print $1","$2}' | grep 'docker-content-digest\|content-type' | jq -R 'split(",") | {(if .[0] == "content-type" then "type" else "digest" end): .[1]}' | jq -s 'reduce .[] as $item ({}; . * $item)')
-    manifest_v2=$(jq -r '. | select(.type == "application/vnd.docker.distribution.manifest.v2+json" or .type == "application/vnd.oci.image.manifest.v1+json") | [{digest: .digest, platform: "linux/amd64"}]' <<<"$headers")
+    manifest_v2=$(jq -r '. | select(.type == "application/vnd.docker.distribution.manifest.v2+json" or .type == "application/vnd.oci.image.manifest.v1+json") | [{digest: .digest, platforms: ["linux/amd64"]}]' <<<"$headers")
     if [ ! -z "$manifest_v2" ]; then
         echo "$manifest_v2"
         return
     fi
 
-    jq -r '[.manifests[] | select(.platform.architecture | contains ("unknown") | not) | {digest: .digest, platform: (.platform.os +"/"+ .platform.architecture)}]' <<<"$manifest_list"
-
+    manifests_with_variant=$(jq -r '[.manifests[] | select(.platform.architecture | contains ("unknown") | not) | select(.platform.variant != null) | {digest: .digest, platforms: [(.platform.os +"/"+ .platform.architecture +"/"+ .platform.variant), (.platform.os +"/"+ .platform.architecture)] }]' <<<"$manifest_list")
+    manifests_without_variant=$(jq -r '[.manifests[] | select(.platform.architecture | contains ("unknown") | not) | select(.platform.variant == null) | {digest: .digest, platforms: [(.platform.os +"/"+ .platform.architecture)]}]' <<<"$manifest_list")
+    # Concat both lists
+    echo "${manifests_with_variant}${manifests_without_variant}" | jq -s 'flatten(1)'
 }
 
 get_layers() {
@@ -111,15 +113,15 @@ diff=false
 # loop through plafforms split by comma
 for platform in $(echo $platforms | tr -s ',' ' '); do
     # get the digest for the platform
-    digest_base=$(jq -r ".[] | select(.platform == \"$platform\") | .digest" <<<"$manifests_base")
+    digest_base=$(jq -r ".[] | select(.platforms[] == \"$platform\") | .digest" <<<"$manifests_base")
 
     # if the digest is empty, then the platform is not present in the base image
     if [ -z "$digest_base" ]; then
         error "Platform $platform not found in the base image $base"
     fi
 
     # get the digest for the platform
-    digest_image=$(jq -r ".[] | select(.platform == \"$platform\") | .digest" <<<"$manifests_image")
+    digest_image=$(jq -r ".[] | select(.platforms[] == \"$platform\") | .digest" <<<"$manifests_image")
 
     # if the digest is empty, then the platform is not present in the image
     if [ -z "$digest_image" ]; then