propagate BUILD_VERSION and BUILD_DATE to docker build/buildx (#105)

Author: dgrove-oss

Dockerfile

@@ -2,6 +2,8 @@
 FROM golang:1.21 AS builder
 ARG TARGETOS
 ARG TARGETARCH
+ARG BUILD_VERSION=Unknown
+ARG BUILD_DATE=Unknown
 
 WORKDIR /workspace
 # Copy the Go Modules manifests
@@ -22,7 +24,9 @@ COPY pkg/ pkg/
 # was called. For example, if we call make docker-build in a local env which has the Apple Silicon M1 SO
 # the docker BUILDPLATFORM arg will be linux/arm64 when for Apple x86 it will be linux/amd64. Therefore,
 # by leaving it empty we can ensure that the container and binary shipped on it will have the same platform.
-RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -a -o manager cmd/main.go
+RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -a \
+    -ldflags "-X 'main.BuildVersion=${BUILD_VERSION}' -X 'main.BuildDate=${BUILD_DATE}'" \
+    -o manager cmd/main.go
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details

Makefile

@@ -139,7 +139,7 @@ build: manifests generate fmt vet ## Build manager binary.
 # More info: https://docs.docker.com/develop/develop-images/build_enhancements/
 .PHONY: docker-build
 docker-build: ## Build docker image with the manager.
-	$(CONTAINER_TOOL) build -t ${IMG} .
+	$(CONTAINER_TOOL) build --build-arg='BUILD_VERSION=$(BUILD_VERSION)' --build-arg='BUILD_DATE=$(BUILD_DATE)' -t ${IMG} .
 
 .PHONY: docker-push
 docker-push: ## Push docker image with the manager.
@@ -162,7 +162,7 @@ docker-buildx: ## Build and push docker image for the manager for cross-platform
 	sed -e '1 s/\(^FROM\)/FROM --platform=\$$\{BUILDPLATFORM\}/; t' -e ' 1,// s//FROM --platform=\$$\{BUILDPLATFORM\}/' Dockerfile > Dockerfile.cross
 	- $(CONTAINER_TOOL) buildx create --name project-v3-builder
 	$(CONTAINER_TOOL) buildx use project-v3-builder
-	- $(CONTAINER_TOOL) buildx build --push --platform=$(PLATFORMS) --tag ${IMG} -f Dockerfile.cross .
+	- $(CONTAINER_TOOL) buildx build --build-arg='BUILD_VERSION=$(BUILD_VERSION)' --build-arg='BUILD_DATE=$(BUILD_DATE)' --push --platform=$(PLATFORMS) --tag ${IMG} -f Dockerfile.cross .
 	- $(CONTAINER_TOOL) buildx rm project-v3-builder
 	rm Dockerfile.cross