Add build info metric (valkey-io#106)

Add a `valkey_operator_build_info` metric. This allows tracking of
rollouts via metrics. This uses the standard Prometheus version
collector helper package and injects the build context via Go build
ldflags.

Signed-off-by: SuperQ <superq@gmail.com>

Author: SuperQ

CONTRIBUTING.md

@@ -193,8 +193,8 @@ make install    # Install CRDs
 make run        # Run controller locally
 
 # 5. Build and test container
-make docker-build IMG=valkey-operator:dev
-make deploy IMG=valkey-operator:dev
+make docker-build IMG=valkey-operator VERSION=dev
+make deploy IMG=valkey-operator VERSION=dev
 ```
 
 ## Code Review Process

Dockerfile

@@ -2,6 +2,7 @@
 FROM golang:1.25 AS builder
 ARG TARGETOS
 ARG TARGETARCH
+ARG LDFLAGS
 
 WORKDIR /workspace
 # Copy the Go Modules manifests
@@ -19,7 +20,7 @@ COPY . .
 # 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 "${LDFLAGS}" -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

@@ -1,5 +1,7 @@
 # Image URL to use all building/pushing image targets
-IMG ?= controller:latest
+VERSION              ?= latest
+IMG                  ?= controller
+CONTAINER_IMAGE_NAME ?= $(IMG):$(VERSION)
 
 # Get the currently used golang install path (in GOPATH/bin, unless GOBIN is set)
 ifeq (,$(shell go env GOBIN))
@@ -19,6 +21,16 @@ CONTAINER_TOOL ?= docker
 SHELL = /usr/bin/env bash -o pipefail
 .SHELLFLAGS = -ec
 
+BRANCH    ?= $(shell git rev-parse --abbrev-ref HEAD)
+BUILDDATE ?= $(shell date -Iseconds)
+REVISION  ?= $(shell git rev-parse HEAD)
+
+VERSION_LDFLAGS := \
+  -X github.com/prometheus/common/version.Version=$(VERSION) \
+  -X github.com/prometheus/common/version.Revision=$(REVISION) \
+  -X github.com/prometheus/common/version.Branch=$(BRANCH) \
+  -X github.com/prometheus/common/version.BuildDate=$(BUILDDATE)
+
 .PHONY: all
 all: build
 
@@ -106,7 +118,7 @@ lint-config: golangci-lint ## Verify golangci-lint linter configuration
 
 .PHONY: build
 build: manifests generate fmt vet lint ## Build manager binary.
-	go build -o bin/manager cmd/main.go
+	go build -ldflags "$(VERSION_LDFLAGS)" -o bin/manager cmd/main.go
 
 .PHONY: run
 run: manifests generate fmt vet ## Run a controller from your host.
@@ -117,17 +129,17 @@ run: manifests generate fmt vet ## Run a controller from your host.
 # 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} .
+	$(CONTAINER_TOOL) build --build-arg "LDFLAGS=$(VERSION_LDFLAGS)" -t ${CONTAINER_IMAGE_NAME} .
 
 .PHONY: docker-push
 docker-push: ## Push docker image with the manager.
-	$(CONTAINER_TOOL) push ${IMG}
+	$(CONTAINER_TOOL) push ${CONTAINER_IMAGE_NAME}
 
 # PLATFORMS defines the target platforms for the manager image be built to provide support to multiple
-# architectures. (i.e. make docker-buildx IMG=myregistry/mypoperator:0.0.1). To use this option you need to:
+# architectures. (i.e. make docker-buildx IMG=myregistry/mypoperator VERSION=0.0.1). To use this option you need to:
 # - be able to use docker buildx. More info: https://docs.docker.com/build/buildx/
 # - have enabled BuildKit. More info: https://docs.docker.com/develop/develop-images/build_enhancements/
-# - be able to push the image to your registry (i.e. if you do not set a valid value via IMG=<myregistry/image:<tag>> then the export will fail)
+# - be able to push the image to your registry (i.e. if you do not set a valid value via IMG=<myregistry/image VERSION:<tag>> then the export will fail)
 # To adequately provide solutions that are compatible with multiple platforms, you should consider using this option.
 PLATFORMS ?= linux/arm64,linux/amd64,linux/s390x,linux/ppc64le
 .PHONY: docker-buildx
@@ -136,14 +148,14 @@ 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 valkey-operator-builder
 	$(CONTAINER_TOOL) buildx use valkey-operator-builder
-	- $(CONTAINER_TOOL) buildx build --push --platform=$(PLATFORMS) --tag ${IMG} -f Dockerfile.cross .
+	- $(CONTAINER_TOOL) buildx build --push --platform=$(PLATFORMS) --build-arg "LDFLAGS=$(VERSION_LDFLAGS)" --tag ${CONTAINER_IMAGE_NAME} -f Dockerfile.cross .
 	- $(CONTAINER_TOOL) buildx rm valkey-operator-builder
 	rm Dockerfile.cross
 
 .PHONY: build-installer
 build-installer: manifests generate kustomize ## Generate a consolidated YAML with CRDs and deployment.
 	mkdir -p dist
-	cd config/manager && "$(KUSTOMIZE)" edit set image controller=${IMG}
+	cd config/manager && "$(KUSTOMIZE)" edit set image controller=${CONTAINER_IMAGE_NAME}
 	"$(KUSTOMIZE)" build config/default > dist/install.yaml
 
 ##@ Deployment
@@ -164,7 +176,7 @@ uninstall: manifests kustomize ## Uninstall CRDs from the K8s cluster specified
 
 .PHONY: deploy
 deploy: manifests kustomize ## Deploy controller to the K8s cluster specified in ~/.kube/config.
-	cd config/manager && "$(KUSTOMIZE)" edit set image controller=${IMG}
+	cd config/manager && "$(KUSTOMIZE)" edit set image controller=${CONTAINER_IMAGE_NAME}
 	"$(KUSTOMIZE)" build config/default | "$(KUBECTL)" apply -f -
 
 .PHONY: undeploy

README.md

@@ -41,7 +41,7 @@ Valkey Operator is a Kubernetes operator that automates the deployment and manag
 **Build and push your image to the location specified by `IMG`:**
 
 ```sh
-make docker-build docker-push IMG=<some-registry>/valkey-operator:tag
+make docker-build docker-push IMG=<some-registry>/valkey-operator VERSION=tag
 ```
 
 **NOTE:** This image ought to be published in the personal registry you specified.
@@ -57,7 +57,7 @@ make install
 **Deploy the Manager to the cluster with the image specified by `IMG`:**
 
 ```sh
-make deploy IMG=<some-registry>/valkey-operator:tag
+make deploy IMG=<some-registry>/valkey-operator VERSION=tag
 ```
 
 > **NOTE**: If you encounter RBAC errors, you may need to grant yourself cluster-admin privileges or be logged in as admin.
@@ -100,7 +100,7 @@ Following the options to release and provide this solution to the users.
 1. Build the installer for the image built and published in the registry:
 
 ```sh
-make build-installer IMG=<some-registry>/valkey-operator:tag
+make build-installer IMG=<some-registry>/valkey-operator VERSION=tag
 ```
 
 **NOTE:** The makefile target mentioned above generates an 'install.yaml'

cmd/main.go

@@ -26,12 +26,14 @@ import (
 	"go.uber.org/zap/zapcore"
 	_ "k8s.io/client-go/plugin/pkg/client/auth"
 
+	versioncollector "github.com/prometheus/client_golang/prometheus/collectors/version"
 	"k8s.io/apimachinery/pkg/runtime"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
 	"sigs.k8s.io/controller-runtime/pkg/metrics/filters"
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
@@ -89,6 +91,8 @@ func main() {
 
 	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
 
+	metrics.Registry.MustRegister(versioncollector.NewCollector("valkey_operator"))
+
 	// if the enable-http2 flag is false (the default), http/2 should be disabled
 	// due to its vulnerabilities. More specifically, disabling http/2 will
 	// prevent from being vulnerable to the HTTP/2 Stream Cancellation and

go.mod

@@ -5,6 +5,7 @@ go 1.25.3
 require (
 	github.com/onsi/ginkgo/v2 v2.27.2
 	github.com/onsi/gomega v1.38.2
+	github.com/prometheus/client_golang v1.23.2
 	github.com/stretchr/testify v1.11.1
 	github.com/valkey-io/valkey-go v1.0.68
 	go.uber.org/zap v1.27.0
@@ -50,7 +51,6 @@ require (
 	github.com/modern-go/reflect2 v1.0.3-0.20250322232337-35a7c28c31ee // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/prometheus/client_golang v1.23.2 // indirect
 	github.com/prometheus/client_model v0.6.2 // indirect
 	github.com/prometheus/common v0.66.1 // indirect
 	github.com/prometheus/procfs v0.16.1 // indirect

test/e2e/e2e_suite_test.go

@@ -49,7 +49,8 @@ const valkeyClientImage = "valkey/valkey:9.0.0"
 
 var (
 	// managerImage is the manager image to be built and loaded for testing.
-	managerImage = "valkey/valkey-operator:v0.0.1"
+	managerImage   = "valkey/valkey-operator"
+	managerVersion = "v0.0.1"
 	// shouldCleanupCertManager tracks whether CertManager was installed by this suite.
 	shouldCleanupCertManager = false
 )
@@ -71,12 +72,12 @@ var _ = BeforeSuite(func() {
 	ExpectWithOffset(1, err).NotTo(HaveOccurred(), "Failed to purge old events")
 
 	By("building the manager image")
-	cmd = exec.Command("make", "docker-build", fmt.Sprintf("IMG=%s", managerImage))
+	cmd = exec.Command("make", "docker-build", "IMG="+managerImage, "VERSION="+managerVersion)
 	_, err = utils.Run(cmd)
 	ExpectWithOffset(1, err).NotTo(HaveOccurred(), "Failed to build the manager image")
 
 	By("loading the manager image on Kind")
-	err = utils.LoadImageToKindClusterWithName(managerImage)
+	err = utils.LoadImageToKindClusterWithName(managerImage + ":" + managerVersion)
 	ExpectWithOffset(1, err).NotTo(HaveOccurred(), "Failed to load the manager image into Kind")
 
 	setupCertManager()
@@ -104,7 +105,7 @@ var _ = BeforeSuite(func() {
 	Expect(err).NotTo(HaveOccurred(), "Failed to install CRDs")
 
 	By("deploying the controller-manager")
-	cmd = exec.Command("make", "deploy", fmt.Sprintf("IMG=%s", managerImage))
+	cmd = exec.Command("make", "deploy", "IMG="+managerImage, "VERSION="+managerVersion)
 	_, err = utils.Run(cmd)
 	Expect(err).NotTo(HaveOccurred(), "Failed to deploy the controller-manager")
 })

test/e2e/valkeycluster_test.go

@@ -29,8 +29,8 @@ import (
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
-
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
 	valkeyiov1alpha1 "valkey.io/valkey-operator/api/v1alpha1"
 	"valkey.io/valkey-operator/test/utils"
 )