Add BUILDTIME build argument to Dockerfile and update build workflow to include metadata-based build arguments

Author: wirwolf

.github/workflows/build.yml

@@ -63,7 +63,10 @@ jobs:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           build-args: |
-            COMMIT_HASH=${{ github.sha }}
+            BUILDTIME=${{ fromJSON(steps.meta.outputs.json).labels['org.opencontainers.image.created'] }}
+            VERSION=${{ fromJSON(steps.meta.outputs.json).labels['org.opencontainers.image.version'] }}
+            REVISION=${{ fromJSON(steps.meta.outputs.json).labels['org.opencontainers.image.revision'] }}
+
 
       - name: Extract file from pushed image
         if: github.ref_type == 'tag'

Dockerfile

@@ -25,7 +25,8 @@ COPY . .
 
 # target parameters for cross-compilation
 ARG TARGETOS
-ARG TARGETARCH
+
+ARG BUILDTIME=""
 ARG VERSION="dev"
 ARG REVISION="000000000000000000000000000000"