Add last git commit hash to build flags

This ensures we have the git hash of the changes in our CI logs
so we can correlate the code changes being executed.

Makefile

@@ -235,7 +235,7 @@ kind-delete: ## Delete the kind cluster
 
 .PHONY: build
 build: generate fmt ## Build manager binary.
-	go build -o bin/manager main.go
+	go build -ldflags "-X main.gitCommit=$(git rev-parse HEAD)" -o bin/manager main.go
 
 .PHONY: run
 run: manifests generate fmt vet ## Run a controller from your host.
@@ -330,7 +330,7 @@ cluster-templates: $(KUSTOMIZE) ## Generate cluster templates for all flavors
 
 .PHONY: docker-build-e2e
 docker-build-e2e: $(KO) ## Build docker image with the manager with e2e tag.
-	KO_DOCKER_REPO=ko.local $(KO) build -B --platform=${PLATFORMS_E2E} -t e2e -L .
+	KO_DOCKER_REPO=ko.local $(KO) build -B --platform=${PLATFORMS_E2E} --build-arg GIT_COMMIT_HASH=$(git rev-parse HEAD) -t e2e -L .
 	docker tag ko.local/cluster-api-provider-nutanix:e2e ${IMG_REPO}:e2e
 
 .PHONY: prepare-local-clusterctl

hack/ensure-go.sh

@@ -31,7 +31,7 @@ EOF
   local go_version
   IFS=" " read -ra go_version <<< "$(go version)"
   local minimum_go_version
-  minimum_go_version=go1.18.3
+  minimum_go_version=go1.21.4
   if [[ "${minimum_go_version}" != $(echo -e "${minimum_go_version}\n${go_version[2]}" | sort -s -t. -k 1,1 -k 2,2n -k 3,3n | head -n1) && "${go_version[2]}" != "devel" ]]; then
     cat <<EOF
 Detected go version: ${go_version[*]}.

hack/install-go.sh

@@ -4,8 +4,8 @@ set -o errexit
 set -o nounset
 set -o pipefail
 
-wget https://go.dev/dl/go1.18.4.linux-amd64.tar.gz
-rm -rf /usr/local/go && tar -C /usr/local -xzf go1.18.4.linux-amd64.tar.gz
+wget https://go.dev/dl/go1.21.4.linux-amd64.tar.gz
+rm -rf /usr/local/go && tar -C /usr/local -xzf go1.21.4.linux-amd64.tar.gz
 export PATH=$PATH:/usr/local/go/bin
 go version
 

main.go

@@ -55,6 +55,9 @@ var (
 	setupLog = ctrl.Log.WithName("setup")
 )
 
+// gitCommit is the git commit hash of the code that is running.
+var gitCommit string
+
 func init() {
 	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
 
@@ -71,6 +74,9 @@ func init() {
 const (
 	// DefaultMaxConcurrentReconciles is the default maximum number of concurrent reconciles
 	defaultMaxConcurrentReconciles = 10
+
+	// GIT_COMMIT_HASH_ENVVAR overrides the git commit hash provided by build flags
+	GIT_COMMIT_HASH_ENVVAR = "GIT_COMMIT_HASH"
 )
 
 func main() {
@@ -80,6 +86,7 @@ func main() {
 		probeAddr               string
 		maxConcurrentReconciles int
 	)
+
 	flag.StringVar(&metricsAddr, "metrics-bind-address", ":8080", "The address the metric endpoint binds to.")
 	flag.StringVar(&probeAddr, "health-probe-bind-address", ":8081", "The address the probe endpoint binds to.")
 	flag.BoolVar(&enableLeaderElection, "leader-elect", false,
@@ -90,6 +97,7 @@ func main() {
 		"max-concurrent-reconciles",
 		defaultMaxConcurrentReconciles,
 		"The maximum number of allowed, concurrent reconciles.")
+
 	opts := zap.Options{
 		TimeEncoder: zapcore.RFC3339TimeEncoder,
 	}
@@ -98,6 +106,11 @@ func main() {
 
 	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
 
+	commitHash := gitCommit
+	if envCommitHash := os.Getenv(GIT_COMMIT_HASH_ENVVAR); envCommitHash != "" {
+		commitHash = envCommitHash
+	}
+
 	mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
 		Scheme:                 scheme,
 		MetricsBindAddress:     metricsAddr,
@@ -111,7 +124,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	// Setup the context that's going to be used in controllers and for the manager.
+	// Set up the context that's going to be used in controllers and for the manager.
 	ctx := ctrl.SetupSignalHandler()
 
 	// Create a secret informer for the Nutanix client
@@ -173,7 +186,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	setupLog.Info("starting manager")
+	setupLog.Info("starting CAPX Controller", "gitCommitHash", commitHash)
 	if err := mgr.Start(ctx); err != nil {
 		setupLog.Error(err, "problem running manager")
 		os.Exit(1)

package/docker/Dockerfile

@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM golang:1.16 as builder
+FROM golang:1.21 as builder
 
 WORKDIR /workspace
 # Copy the Go Modules manifests
@@ -15,8 +15,10 @@ COPY api/ api/
 COPY controllers/ controllers/
 COPY pkg/ pkg/
 
+ARG GIT_COMMIT_HASH
+ENV GIT_COMMIT_HASH=${GIT_COMMIT_HASH}
 # Build
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o manager main.go
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags "-X main.gitCommit=$(git rev-parse HEAD)" -a -o manager main.go
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details