operator: Move the CRD registration logic to a separate package

We'll introduce a proper operator deployment in #794. Once the operator
deployment is available, we can move the CRD registration logic there
instead of calling it from an init container in the Tetragon daemonset.
This commit moves the CRD registration logic to a separate package so
that it can be called from outside the main package.

Signed-off-by: Michi Mutsuzaki <michi@isovalent.com>

operator/crd/crd.go

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Authors of Tetragon
+
+package crd
+
+import (
+	"fmt"
+
+	"github.com/cilium/cilium/pkg/logging"
+	"github.com/cilium/cilium/pkg/logging/logfields"
+	"github.com/cilium/tetragon/operator/option"
+	"github.com/cilium/tetragon/pkg/k8s/apis/cilium.io/client"
+	"github.com/cilium/tetragon/pkg/k8s/version"
+	version2 "github.com/cilium/tetragon/pkg/version"
+	"github.com/sirupsen/logrus"
+	"k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+var log = logging.DefaultLogger.WithField(logfields.LogSubsys, "crd")
+
+func RegisterCRDs() {
+	restConfig, err := getConfig()
+	if err != nil {
+		log.WithError(err).Fatal("Unable to check k8s configuration")
+	}
+
+	k8sClient, err := kubernetes.NewForConfig(restConfig)
+	if err != nil {
+		log.WithError(err).Fatal("Unable to create k8s client")
+	}
+
+	k8sAPIExtClient, err := clientset.NewForConfig(restConfig)
+	if err != nil {
+		log.WithError(err).Fatal("Unable to create k8s API ext. client")
+	}
+
+	err = version.UpdateK8sServerVersion(k8sClient)
+	if err != nil {
+		log.WithError(err).Fatal("Unable to check k8s version")
+	}
+
+	log.WithFields(logrus.Fields{
+		"config":  fmt.Sprintf("%+v", option.Config),
+		"version": version2.Version,
+	}).Info("Starting Tetragon Operator")
+	capabilities := version.Capabilities()
+	if !capabilities.MinimalVersionMet {
+		log.Fatalf("Minimal kubernetes version not met: %s < %s",
+			version.Version(), version.MinimalVersionConstraint)
+	}
+
+	// Register the CRDs after validating that we are running on a supported
+	// version of K8s.
+	if !option.Config.SkipCRDCreation {
+		if err := client.RegisterCRDs(k8sAPIExtClient); err != nil {
+			log.WithError(err).Fatal("Unable to register CRDs")
+		}
+	} else {
+		log.Info("Skipping creation of CRDs")
+	}
+
+	log.Info("Initialization complete")
+}
+
+func getConfig() (*rest.Config, error) {
+	if option.Config.KubeCfgPath != "" {
+		return clientcmd.BuildConfigFromFlags("", option.Config.KubeCfgPath)
+	}
+	return rest.InClusterConfig()
+}

operator/main.go

@@ -19,20 +19,13 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/cilium/tetragon/operator/crd"
 	operatorOption "github.com/cilium/tetragon/operator/option"
-	"github.com/cilium/tetragon/pkg/k8s/apis/cilium.io/client"
-	k8sversion "github.com/cilium/tetragon/pkg/k8s/version"
-	"github.com/cilium/tetragon/pkg/version"
-	"k8s.io/client-go/kubernetes"
-	"k8s.io/client-go/tools/clientcmd"
 
 	"github.com/cilium/cilium/pkg/logging"
 	"github.com/cilium/cilium/pkg/logging/logfields"
-	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
-	apiextclientset "k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
-	"k8s.io/client-go/rest"
 )
 
 var (
@@ -44,70 +37,18 @@ var (
 		Use:   binaryName,
 		Short: "Run " + binaryName,
 		Run: func(cmd *cobra.Command, args []string) {
+			// Populate option.Config with options from CLI.
+			configPopulate()
 			cmdRefDir := viper.GetString(operatorOption.CMDRef)
 			if cmdRefDir != "" {
 				genMarkdown(cmd, cmdRefDir)
 				os.Exit(0)
 			}
-			operatorExecute()
+			crd.RegisterCRDs()
 		},
 	}
 )
 
-func getConfig() (*rest.Config, error) {
-	if operatorOption.Config.KubeCfgPath != "" {
-		return clientcmd.BuildConfigFromFlags("", operatorOption.Config.KubeCfgPath)
-	}
-	return rest.InClusterConfig()
-}
-
-func operatorExecute() {
-	// Prepopulate option.Config with options from CLI.
-	configPopulate()
-
-	restConfig, err := getConfig()
-	if err != nil {
-		log.WithError(err).Fatal("Unable to check k8s configuration")
-	}
-
-	k8sClient, err := kubernetes.NewForConfig(restConfig)
-	if err != nil {
-		log.WithError(err).Fatal("Unable to create k8s client")
-	}
-
-	k8sAPIExtClient, err := apiextclientset.NewForConfig(restConfig)
-	if err != nil {
-		log.WithError(err).Fatal("Unable to create k8s API ext. client")
-	}
-
-	err = k8sversion.UpdateK8sServerVersion(k8sClient)
-	if err != nil {
-		log.WithError(err).Fatal("Unable to check k8s version")
-	}
-
-	log.WithFields(logrus.Fields{
-		"config":  fmt.Sprintf("%+v", operatorOption.Config),
-		"version": version.Version,
-	}).Info("Starting Tetragon Operator")
-	capabilities := k8sversion.Capabilities()
-	if !capabilities.MinimalVersionMet {
-		log.Fatalf("Minimal kubernetes version not met: %s < %s",
-			k8sversion.Version(), k8sversion.MinimalVersionConstraint)
-	}
-
-	// Register the CRDs after validating that we are running on a supported
-	// version of K8s.
-	if !operatorOption.Config.SkipCRDCreation {
-		if err := client.RegisterCRDs(k8sAPIExtClient); err != nil {
-			log.WithError(err).Fatal("Unable to register CRDs")
-		}
-	} else {
-		log.Info("Skipping creation of CRDs")
-	}
-
-	log.Info("Initialization complete")
-}
-
 func main() {
 	if err := rootCmd.Execute(); err != nil {
 		fmt.Println(err)