main.go

/*******************************************************************************
* IBM Cloud Kubernetes Service, 5737-D43
* (C) Copyright IBM Corp. 2019, 2024 All Rights Reserved.
*
* SPDX-License-Identifier: Apache2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*******************************************************************************/

// References:
// - https://raw.githubusercontent.com/kubernetes/kubernetes/v1.32.0/staging/src/k8s.io/cloud-provider/app/controllermanager.go
// - https://raw.githubusercontent.com/kubernetes/kubernetes/v1.32.0/staging/src/k8s.io/cloud-provider/sample/basic_main.go

package main

import (
	"fmt"
	"os"

	"cloud.ibm.com/cloud-provider-ibm/ibm"
	"github.com/spf13/cobra"
	"k8s.io/apimachinery/pkg/util/wait"
	cloudprovider "k8s.io/cloud-provider"
	"k8s.io/cloud-provider/app"
	"k8s.io/cloud-provider/app/config"
	"k8s.io/cloud-provider/names"
	"k8s.io/cloud-provider/options"
	"k8s.io/component-base/cli"
	cliflag "k8s.io/component-base/cli/flag"
	"k8s.io/component-base/cli/globalflag"
	_ "k8s.io/component-base/metrics/prometheus/clientgo" // load all the prometheus client-go plugins
	_ "k8s.io/component-base/metrics/prometheus/version"  // for version metric registration
	"k8s.io/component-base/term"
	"k8s.io/klog/v2"
)

func main() {
	ccmOptions, err := options.NewCloudControllerManagerOptions()
	if err != nil {
		klog.Fatalf("unable to initialize IBM Cloud controller manager command options: %v", err)
	}

	// set IBM cloud provider name
	ccmOptions.KubeCloudShared.CloudProvider.Name = ibm.ProviderName

	// IBM cloud does not need the "route" implementation
	controllerInitializers := app.DefaultInitFuncConstructors
	delete(controllerInitializers, "route")

	fss := cliflag.NamedFlagSets{}
	command := NewCloudControllerManagerCommand(ccmOptions, IBMCloudInitializer, controllerInitializers, fss, wait.NeverStop)
	code := cli.Run(command)
	if code != 0 {
		os.Exit(code)
	}
}

func NewCloudControllerManagerCommand(s *options.CloudControllerManagerOptions, cloudInitializer app.InitCloudFunc, initFuncConstructor map[string]app.ControllerInitFuncConstructor, additionalFlags cliflag.NamedFlagSets, stopCh <-chan struct{}) *cobra.Command {
	cmd := &cobra.Command{
		Use: "ibm-cloud-controller-manager",
		Long: `The IBM Cloud controller manager is a daemon that embeds
the cloud specific control loops shipped with Kubernetes.`,
		RunE: func(cmd *cobra.Command, args []string) error {
			ibm.PrintVersionAndExitIfRequested()
			cliflag.PrintFlags(cmd.Flags())

			c, err := s.Config(app.ControllerNames(initFuncConstructor), app.ControllersDisabledByDefault.List(), names.CCMControllerAliases(), app.AllWebhooks, app.DisabledByDefaultWebhooks)
			if err != nil {
				fmt.Fprintf(os.Stderr, "%v\n", err)
				return err
			}

			completedConfig := c.Complete()
			cloud := cloudInitializer(completedConfig)
			controllerInitializers := app.ConstructControllerInitializers(initFuncConstructor, completedConfig, cloud)

			if err := app.Run(completedConfig, cloud, controllerInitializers, nil, stopCh); err != nil {
				fmt.Fprintf(os.Stderr, "%v\n", err)
				return err
			}
			return nil
		},
		Args: func(cmd *cobra.Command, args []string) error {
			for _, arg := range args {
				if len(arg) > 0 {
					return fmt.Errorf("%q does not take any arguments, got %q", cmd.CommandPath(), args)
				}
			}
			return nil
		},
	}

	fs := cmd.Flags()
	namedFlagSets := s.Flags(app.ControllerNames(initFuncConstructor), app.ControllersDisabledByDefault.List(), names.CCMControllerAliases(), app.AllWebhooks, app.DisabledByDefaultWebhooks)
	ibm.AddVersionFlag(namedFlagSets.FlagSet("global"))
	globalflag.AddGlobalFlags(namedFlagSets.FlagSet("global"), cmd.Name())

	for _, f := range namedFlagSets.FlagSets {
		fs.AddFlagSet(f)
	}
	for _, f := range additionalFlags.FlagSets {
		fs.AddFlagSet(f)
	}

	usageFmt := "Usage:\n  %s\n"
	cols, _, _ := term.TerminalSize(cmd.OutOrStdout()) // #nosec G104 Error handling is handled below
	cmd.SetUsageFunc(func(cmd *cobra.Command) error {
		fmt.Fprintf(cmd.OutOrStderr(), usageFmt, cmd.UseLine())
		cliflag.PrintSections(cmd.OutOrStderr(), namedFlagSets, cols)
		return nil
	})
	cmd.SetHelpFunc(func(cmd *cobra.Command, args []string) {
		fmt.Fprintf(cmd.OutOrStdout(), "%s\n\n"+usageFmt, cmd.Long, cmd.UseLine())
		cliflag.PrintSections(cmd.OutOrStdout(), namedFlagSets, cols)
	})

	return cmd
}

func IBMCloudInitializer(config *config.CompletedConfig) cloudprovider.Interface {
	cloudConfig := config.ComponentConfig.KubeCloudShared.CloudProvider

	// initialize cloud provider with the cloud provider name and config file provided
	cloud, err := cloudprovider.InitCloudProvider(cloudConfig.Name, cloudConfig.CloudConfigFile)
	if err != nil {
		klog.Fatalf("IBM Cloud provider could not be initialized: %v", err)
	}
	if cloud == nil {
		klog.Fatalf("IBM Cloud provider is nil")
	}

	return cloud
}