From 7960ff1adc87f5693b79c1d8b117e5895afef33c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ra=C3=BAl=20Naveiras?= <me@raulnaveiras.com>
Date: Thu, 15 Jun 2023 22:12:45 +0100
Subject: [PATCH] Add Prometheus build_info metrics

```
theatre_build_info{commit="none",goarch="arm64",goos="linux",goversion="go1.20.5",version="dev"} 1
```

This is a good practice that should be in all our binaries
---
 Makefile                                       |  2 +-
 apis/vault/v1alpha1/secretsinjector_webhook.go |  6 ------
 cmd/helpers.go                                 | 18 ++++++++++++++++++
 cmd/rbac-manager/main.go                       |  4 ++++
 cmd/vault-manager/main.go                      |  6 ++++++
 cmd/workloads-manager/main.go                  |  4 ++++
 6 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index 13c8cd9a..87f5adde 100644
--- a/Makefile
+++ b/Makefile
@@ -51,7 +51,7 @@ acceptance-prepare: install-tools
 	go run cmd/acceptance/main.go prepare --verbose
 
 acceptance-destroy: install-tools
-	go run cmd/acceptance/main.go prepare --verbose
+	go run cmd/acceptance/main.go destroy
 
 generate: install-tools
 	controller-gen object paths="./apis/rbac/..."
diff --git a/apis/vault/v1alpha1/secretsinjector_webhook.go b/apis/vault/v1alpha1/secretsinjector_webhook.go
index a961d12a..3201871e 100644
--- a/apis/vault/v1alpha1/secretsinjector_webhook.go
+++ b/apis/vault/v1alpha1/secretsinjector_webhook.go
@@ -15,7 +15,6 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	"sigs.k8s.io/controller-runtime/pkg/client"
-	"sigs.k8s.io/controller-runtime/pkg/metrics"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 )
 
@@ -88,11 +87,6 @@ var (
 	)
 )
 
-func init() {
-	// Register custom metrics with the global controller runtime prometheus registry
-	metrics.Registry.MustRegister(handleTotal, mutateTotal, skipTotal, errorsTotal)
-}
-
 func (i *SecretsInjector) Handle(ctx context.Context, req admission.Request) (resp admission.Response) {
 	labels := prometheus.Labels{"pod_namespace": req.Namespace}
 	logger := i.logger.WithValues("uuid", string(req.UID))
diff --git a/cmd/helpers.go b/cmd/helpers.go
index e674fba1..230c694c 100644
--- a/cmd/helpers.go
+++ b/cmd/helpers.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/alecthomas/kingpin"
 	"github.com/go-logr/logr"
+	"github.com/prometheus/client_golang/prometheus"
 	zaplogfmt "github.com/sykesm/zap-logfmt"
 	zapopt "go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
@@ -77,3 +78,20 @@ func VersionStanza() string {
 		Version, Commit, GoVersion, runtime.GOOS, runtime.GOARCH, Date,
 	)
 }
+
+var (
+	BuildInfo = prometheus.NewGaugeFunc(
+		prometheus.GaugeOpts{
+			Name: "theatre_build_info",
+			Help: "A metric with a constant '1' value labeled by version, commit, goversion from which %s was built, and the goos and goarch for the build.",
+			ConstLabels: prometheus.Labels{
+				"version":   Version,
+				"commit":    Commit,
+				"goversion": GoVersion,
+				"goos":      runtime.GOOS,
+				"goarch":    runtime.GOARCH,
+			},
+		},
+		func() float64 { return 1 },
+	)
+)
diff --git a/cmd/rbac-manager/main.go b/cmd/rbac-manager/main.go
index dbe9ad22..99fb82e9 100644
--- a/cmd/rbac-manager/main.go
+++ b/cmd/rbac-manager/main.go
@@ -14,6 +14,7 @@ import (
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp" // this is required to auth against GCP
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
 
 	rbacv1alpha1 "github.com/gocardless/theatre/v3/apis/rbac/v1alpha1"
 	"github.com/gocardless/theatre/v3/cmd"
@@ -39,6 +40,9 @@ var (
 func init() {
 	_ = clientgoscheme.AddToScheme(scheme)
 	_ = rbacv1alpha1.AddToScheme(scheme)
+
+	// Register custom metrics with the global controller runtime prometheus registry
+	metrics.Registry.MustRegister(cmd.BuildInfo)
 }
 
 func main() {
diff --git a/cmd/vault-manager/main.go b/cmd/vault-manager/main.go
index d00885db..f86326e0 100644
--- a/cmd/vault-manager/main.go
+++ b/cmd/vault-manager/main.go
@@ -8,6 +8,7 @@ import (
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp" // this is required to auth against GCP
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 
 	vaultv1alpha1 "github.com/gocardless/theatre/v3/apis/vault/v1alpha1"
@@ -43,6 +44,11 @@ var (
 	serviceAccountTokenAudience = app.Flag("service-account-token-audience", "Audience for the projected service account token").String()
 )
 
+func init() {
+	// Register custom metrics with the global controller runtime prometheus registry
+	metrics.Registry.MustRegister(cmd.BuildInfo)
+}
+
 func main() {
 	kingpin.MustParse(app.Parse(os.Args[1:]))
 	logger := commonOpts.Logger()
diff --git a/cmd/workloads-manager/main.go b/cmd/workloads-manager/main.go
index 43150f02..b1ab4627 100644
--- a/cmd/workloads-manager/main.go
+++ b/cmd/workloads-manager/main.go
@@ -10,6 +10,7 @@ import (
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp" // this is required to auth against GCP
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 
 	rbacv1alpha1 "github.com/gocardless/theatre/v3/apis/rbac/v1alpha1"
@@ -39,6 +40,9 @@ func init() {
 	_ = clientgoscheme.AddToScheme(scheme)
 	_ = workloadsv1alpha1.AddToScheme(scheme)
 	_ = rbacv1alpha1.AddToScheme(scheme)
+
+	// Register custom metrics with the global controller runtime prometheus registry
+	metrics.Registry.MustRegister(cmd.BuildInfo)
 }
 
 func main() {