Pass ldflags to the Dockerfile (#681)

<!-- Provide a brief summary of your changes -->

## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
The following fixes an issue where the ldflags were not passed to the
Dockerfile, so the binary cannot populate its version-related variables
accordingly

## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->

## Breaking Changes
<!-- Will users need to update their code or configurations? -->

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

Signed-off-by: Radoslav Dimitrov <radoslav@stacklok.com>

.github/workflows/deploy-staging.yml

@@ -34,6 +34,10 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Get build timestamp
+        id: build-time
+        run: echo "timestamp=$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> $GITHUB_OUTPUT
+
       - name: Extract metadata
         id: meta
         uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f
@@ -54,6 +58,10 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
+          build-args: |
+            VERSION=${{ steps.meta.outputs.version }}
+            GIT_COMMIT=${{ github.sha }}
+            BUILD_TIME=${{ steps.build-time.outputs.timestamp }}
 
   deploy-staging:
     name: Deploy to Staging

.github/workflows/release.yml

@@ -56,6 +56,10 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Get build timestamp
+        id: build-time
+        run: echo "timestamp=$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> $GITHUB_OUTPUT
+
       - name: Extract metadata
         id: meta
         uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f
@@ -75,4 +79,8 @@ jobs:
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
-          cache-to: type=gha,mode=max
+          cache-to: type=gha,mode=max
+          build-args: |
+            VERSION=${{ steps.meta.outputs.version }}
+            GIT_COMMIT=${{ github.sha }}
+            BUILD_TIME=${{ steps.build-time.outputs.timestamp }}

Dockerfile

@@ -10,7 +10,14 @@ RUN go mod download
 COPY . .
 
 ARG GO_BUILD_TAGS
-RUN go build ${GO_BUILD_TAGS:+-tags="$GO_BUILD_TAGS"} -o /build/registry ./cmd/registry
+ARG VERSION=dev
+ARG GIT_COMMIT=unknown
+ARG BUILD_TIME=unknown
+
+RUN go build \
+    ${GO_BUILD_TAGS:+-tags="$GO_BUILD_TAGS"} \
+    -ldflags="-X main.Version=${VERSION} -X main.GitCommit=${GIT_COMMIT} -X main.BuildTime=${BUILD_TIME}" \
+    -o /build/registry ./cmd/registry
 
 FROM alpine:latest
 WORKDIR /app