Related to #255

This is first of PR

 -  move environment variable `POD_NAMESPACE` to `depresolver`
 -  extend depresolver tests
 -  extend depresolver validators for namespace validator
 -  Extract Prometheus metrics into standalone module
 -  Extend prometheus metrics
 -  Fix controller tests
 -  remove dead registry/k3s.yaml file (pushed by mistake)

TODO:
  - dnsupdate refactor to provider pattern in next PR
  - fianally, some of utils will go into [gopkg](https://github.com/AbsaOSS/gopkg)
  - IMetrics introduction (#124)

controllers/depresolver/depresolver.go

@@ -65,6 +65,8 @@ type Config struct {
 	EdgeDNSZone string
 	// DNSZone controlled by gslb; e.g. cloud.example.com
 	DNSZone string
+	// K8gbNamespace k8gb namespace
+	K8gbNamespace string
 	// Infoblox configuration
 	Infoblox Infoblox
 	// Override the behavior of GSLB in the test environments

controllers/depresolver/depresolver_config.go

@@ -24,6 +24,7 @@ const (
 	InfobloxPasswordKey     = "EXTERNAL_DNS_INFOBLOX_WAPI_PASSWORD"
 	OverrideWithFakeDNSKey  = "OVERRIDE_WITH_FAKE_EXT_DNS"
 	OverrideFakeInfobloxKey = "FAKE_INFOBLOX"
+	K8gbNamespaceKey        = "POD_NAMESPACE"
 )
 
 // ResolveOperatorConfig executes once. It reads operator's configuration
@@ -39,6 +40,7 @@ func (dr *DependencyResolver) ResolveOperatorConfig() (*Config, error) {
 		dr.config.EdgeDNSServer = env.GetEnvAsStringOrFallback(EdgeDNSServerKey, "")
 		dr.config.EdgeDNSZone = env.GetEnvAsStringOrFallback(EdgeDNSZoneKey, "")
 		dr.config.DNSZone = env.GetEnvAsStringOrFallback(DNSZoneKey, "")
+		dr.config.K8gbNamespace = env.GetEnvAsStringOrFallback(K8gbNamespaceKey, "")
 		dr.config.Infoblox.Host = env.GetEnvAsStringOrFallback(InfobloxGridHostKey, "")
 		dr.config.Infoblox.Version = env.GetEnvAsStringOrFallback(InfobloxVersionKey, "")
 		dr.config.Infoblox.Port, _ = env.GetEnvAsIntOrFallback(InfobloxPortKey, 0)
@@ -53,6 +55,10 @@ func (dr *DependencyResolver) ResolveOperatorConfig() (*Config, error) {
 }
 
 func (dr *DependencyResolver) validateConfig(config *Config) (err error) {
+	err = field("k8gbNamespace", config.K8gbNamespace).isNotEmpty().matchRegexp(k8sNamespaceRegex).err
+	if err != nil {
+		return err
+	}
 	err = field("reconcileRequeueSeconds", config.ReconcileRequeueSeconds).isHigherThanZero().err
 	if err != nil {
 		return err

controllers/depresolver/depresolver_test.go

@@ -28,6 +28,7 @@ var predefinedConfig = Config{
 	EdgeDNSServer:           "cloud.example.com",
 	EdgeDNSZone:             "8.8.8.8",
 	DNSZone:                 "example.com",
+	K8gbNamespace:           "k8gb",
 	Infoblox: Infoblox{
 		"Infoblox.host.com",
 		"0.0.3",
@@ -466,6 +467,37 @@ func TestResolveConfigWithoutDnsZone(t *testing.T) {
 	arrangeVariablesAndAssert(t, expected, assert.Error, DNSZoneKey)
 }
 
+func TestResolveConfigWithEmptyK8gbNamespace(t *testing.T) {
+	// arrange
+	defer cleanup()
+	expected := predefinedConfig
+	expected.K8gbNamespace = ""
+	// act,assert
+	arrangeVariablesAndAssert(t, expected, assert.Error, K8gbNamespaceKey)
+}
+
+func TestResolveConfigWithInvalidK8gbNamespace(t *testing.T) {
+	// arrange
+	defer cleanup()
+	for _, ns := range []string{"-", "Op.", "kube/netes", "my-ns???", "123-MY", "MY-123"} {
+		expected := predefinedConfig
+		expected.K8gbNamespace = ns
+		// act,assert
+		arrangeVariablesAndAssert(t, expected, assert.Error)
+	}
+}
+
+func TestResolveConfigWithValidK8gbNamespace(t *testing.T) {
+	// arrange
+	defer cleanup()
+	for _, ns := range []string{"k8gb", "my-123", "123-my", "n"} {
+		expected := predefinedConfig
+		expected.K8gbNamespace = ns
+		// act,assert
+		arrangeVariablesAndAssert(t, expected, assert.NoError)
+	}
+}
+
 func TestResolveEmptyExtGeoTags(t *testing.T) {
 	// arrange
 	defer cleanup()
@@ -928,7 +960,7 @@ func arrangeVariablesAndAssert(t *testing.T, expected Config,
 func cleanup() {
 	for _, s := range []string{ReconcileRequeueSecondsKey, ClusterGeoTagKey, ExtClustersGeoTagsKey, EdgeDNSZoneKey, DNSZoneKey, EdgeDNSServerKey,
 		Route53EnabledKey, InfobloxGridHostKey, InfobloxVersionKey, InfobloxPortKey, InfobloxUsernameKey, InfobloxPasswordKey,
-		OverrideWithFakeDNSKey, OverrideFakeInfobloxKey} {
+		OverrideWithFakeDNSKey, OverrideFakeInfobloxKey, K8gbNamespaceKey} {
 		if os.Unsetenv(s) != nil {
 			panic(fmt.Errorf("cleanup %s", s))
 		}
@@ -942,6 +974,7 @@ func configureEnvVar(config Config) {
 	_ = os.Setenv(EdgeDNSServerKey, config.EdgeDNSServer)
 	_ = os.Setenv(EdgeDNSZoneKey, config.EdgeDNSZone)
 	_ = os.Setenv(DNSZoneKey, config.DNSZone)
+	_ = os.Setenv(K8gbNamespaceKey, config.K8gbNamespace)
 	_ = os.Setenv(Route53EnabledKey, strconv.FormatBool(config.route53Enabled))
 	_ = os.Setenv(NS1EnabledKey, strconv.FormatBool(config.ns1Enabled))
 	_ = os.Setenv(InfobloxGridHostKey, config.Infoblox.Host)

controllers/depresolver/depresolver_validator.go

@@ -15,6 +15,8 @@ const (
 	ipAddressRegex = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
 	// versionNumberRegex matches version in formats 0.1.2, v0.1.2, v0.1.2-alpha
 	versionNumberRegex = "^(v){0,1}(0|(?:[1-9]\\d*))(?:\\.(0|(?:[1-9]\\d*))(?:\\.(0|(?:[1-9]\\d*)))?(?:\\-([\\w][\\w\\.\\-_]*))?)?$"
+	// k8sNamespaceRegex matches valid kubernetes namespace
+	k8sNamespaceRegex = "^[a-z0-9]([-a-z0-9]*[a-z0-9])?$"
 )
 
 // validator wrapper against field to be verified

controllers/dnsupdate.go

@@ -373,7 +373,7 @@ func Dig(edgeDNSServer, fqdn string) ([]string, error) {
 func (r *GslbReconciler) coreDNSExposedIPs() ([]string, error) {
 	coreDNSService := &corev1.Service{}
 
-	err := r.Get(context.TODO(), types.NamespacedName{Namespace: k8gbNamespace, Name: coreDNSExtServiceName}, coreDNSService)
+	err := r.Get(context.TODO(), types.NamespacedName{Namespace: r.Config.K8gbNamespace, Name: coreDNSExtServiceName}, coreDNSService)
 	if err != nil {
 		if errors.IsNotFound(err) {
 			log.Info(fmt.Sprintf("Can't find %s service", coreDNSExtServiceName))
@@ -411,7 +411,7 @@ func (r *GslbReconciler) createZoneDelegationRecordsForExternalDNS(gslb *k8gbv1b
 	NSRecord := &externaldns.DNSEndpoint{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:        fmt.Sprintf("k8gb-ns-%s", dnsProvider),
-			Namespace:   k8gbNamespace,
+			Namespace:   r.Config.K8gbNamespace,
 			Annotations: map[string]string{"k8gb.absa.oss/dnstype": dnsProvider},
 		},
 		Spec: externaldns.DNSEndpointSpec{
@@ -431,7 +431,7 @@ func (r *GslbReconciler) createZoneDelegationRecordsForExternalDNS(gslb *k8gbv1b
 			},
 		},
 	}
-	res, err := r.ensureDNSEndpoint(k8gbNamespace, NSRecord)
+	res, err := r.ensureDNSEndpoint(r.Config.K8gbNamespace, NSRecord)
 	if err != nil {
 		return res, err
 	}

controllers/finalize.go

@@ -20,7 +20,7 @@ func (r *GslbReconciler) finalizeGslb(gslb *k8gbv1beta1.Gslb) error {
 	if r.Config.EdgeDNSType == depresolver.DNSTypeRoute53 {
 		log.Info("Removing Zone Delegation entries...")
 		dnsEndpointRoute53 := &externaldns.DNSEndpoint{}
-		err := r.Get(context.Background(), client.ObjectKey{Namespace: k8gbNamespace, Name: "k8gb-ns-route53"}, dnsEndpointRoute53)
+		err := r.Get(context.Background(), client.ObjectKey{Namespace: r.Config.K8gbNamespace, Name: "k8gb-ns-route53"}, dnsEndpointRoute53)
 		if err != nil {
 			if errors.IsNotFound(err) {
 				log.Info(fmt.Sprint(err))

controllers/gslb_controller.go

@@ -19,9 +19,10 @@ package controllers
 import (
 	"context"
 	"fmt"
-	"os"
 	"time"
 
+	"github.com/AbsaOSS/k8gb/controllers/metrics"
+
 	"github.com/AbsaOSS/k8gb/controllers/depresolver"
 	"github.com/go-logr/logr"
 	corev1 "k8s.io/api/core/v1"
@@ -41,7 +42,6 @@ import (
 	k8gbv1beta1 "github.com/AbsaOSS/k8gb/api/v1beta1"
 )
 
-var k8gbNamespace = os.Getenv("POD_NAMESPACE")
 var log = logf.Log.WithName("controller_gslb")
 
 // GslbReconciler reconciles a Gslb object
@@ -51,6 +51,7 @@ type GslbReconciler struct {
 	Scheme      *runtime.Scheme
 	Config      *depresolver.Config
 	DepResolver *depresolver.DependencyResolver
+	Metrics     *metrics.PrometheusMetrics
 }
 
 const (