Merge pull request #96385 from cici37/addingSamples

Adding sample files to demonstrate how cloud providers leverage CCM

cmd/cloud-controller-manager/BUILD

@@ -17,7 +17,7 @@ go_binary(
 go_library(
     name = "go_default_library",
     srcs = [
-        "controller-manager.go",
+        "main.go",
         "nodeipamcontroller.go",
         "providers.go",
     ],

cmd/cloud-controller-manager/main.go

@@ -18,6 +18,9 @@ limitations under the License.
 // are cloud provider dependent. It uses the API to listen to new events on resources.
 
 // This file should be written by each cloud provider.
+// For an minimal working example, please refer to k8s.io/cloud-provider/sample/basic_main.go
+// For an advanced example, please refer to k8s.io/cloud-provider/sample/advanced_main.go
+// For more details, please refer to k8s.io/kubernetes/cmd/cloud-controller-manager/main.go
 // The current file demonstrate how other cloud provider should leverage CCM and it uses fake parameters. Please modify for your own use.
 
 package main
@@ -41,16 +44,13 @@ import (
 	genericcontrollermanager "k8s.io/controller-manager/app"
 	"k8s.io/klog/v2"
 	nodeipamconfig "k8s.io/kubernetes/pkg/controller/nodeipam/config"
+	// For existing cloud providers, the option to import legacy providers is still available.
+	// e.g. _"k8s.io/legacy-cloud-providers/<provider>"
 )
 
 const (
-	// cloudProviderName shows an sample of using hard coded parameter
+	// cloudProviderName shows an sample of using hard coded parameter, please edit the value for your case.
 	cloudProviderName = "SampleCloudProviderName"
-
-	// defaultNodeMaskCIDRIPv4 is default mask size for IPv4 node cidr
-	defaultNodeMaskCIDRIPv4 = 24
-	// defaultNodeMaskCIDRIPv6 is default mask size for IPv6 node cidr
-	defaultNodeMaskCIDRIPv6 = 64
 )
 
 func main() {

cmd/cloud-controller-manager/nodeipamcontroller.go

@@ -38,6 +38,13 @@ import (
 	netutils "k8s.io/utils/net"
 )
 
+const (
+	// defaultNodeMaskCIDRIPv4 is default mask size for IPv4 node cidr
+	defaultNodeMaskCIDRIPv4 = 24
+	// defaultNodeMaskCIDRIPv6 is default mask size for IPv6 node cidr
+	defaultNodeMaskCIDRIPv6 = 64
+)
+
 func startNodeIpamController(ccmconfig *cloudcontrollerconfig.CompletedConfig, nodeipamconfig nodeipamconfig.NodeIPAMControllerConfiguration, ctx genericcontrollermanager.ControllerContext, cloud cloudprovider.Interface) (http.Handler, bool, error) {
 	var serviceCIDR *net.IPNet
 	var secondaryServiceCIDR *net.IPNet

staging/src/k8s.io/cloud-provider/sample/BUILD

@@ -2,7 +2,10 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
 go_library(
     name = "go_default_library",
-    srcs = ["main.go"],
+    srcs = [
+        "advanced_main.go",
+        "basic_main.go",
+    ],
     importmap = "k8s.io/kubernetes/vendor/k8s.io/cloud-provider/sample",
     importpath = "k8s.io/cloud-provider/sample",
     visibility = ["//visibility:public"],

staging/src/k8s.io/cloud-provider/sample/README.md

@@ -0,0 +1,20 @@
+# cloud-provider/sample
+
+This directory provides sample code about how all cloud providers should leverage CCM begin at 1.20.
+
+## Purpose
+
+Begin with 1.20, all cloud providers should not copy over or vender in `k8s.io/kubernetes/cmd/cloud-controller-manager`. Inside this directory, some sample code will be provided to demonstrate how cloud providers should leverage cloud-controller-manager. 
+
+## Steps cloud providers shoud follow
+
+1. Have your external repo under k8s.io. e.g. `k8s.io/cloud-provider-<provider>`
+2. Create `main.go` file under your external repo CCM directory. Please refer to `basic_main.go` for a minial working sample and `advanced_main.go` for advanced configuration samples.
+Note: If you have a requirement of adding/deleting controllers within CCM, please refer to `k8s.io/kubernetes/cmd/cloud-controller-manager/main.go` for detailed samples.
+3. Build/release CCM from your external repo. For existing cloud providers, the option to import legacy providers from `k8s.io/legacy-cloud-provider/<provider>` is still available.
+
+## Things you should NOT do
+
+ 1. Vendor in `k8s.io/cmd/cloud-controller-manager`.
+ 2. Directly modify anything under `vendor/k8s.io/cloud-provider/sample` in this repo. Those are driven from `k8s.io/kubernetes/staging/src/k8s.io/cloud-provider/sample`.
+ 3. Make specific cloud provider changes in sample files.

staging/src/k8s.io/cloud-provider/sample/advanced_main.go

@@ -15,7 +15,9 @@ limitations under the License.
 */
 
 // This file should be written by each cloud provider.
-// This is an minimal example. For more details, please refer to k8s.io/kubernetes/cmd/cloud-controller-manager/controller-manager.go
+// For an minimal working example, please refer to k8s.io/cloud-provider/sample/basic_main.go
+// For an advanced example, please refer to k8s.io/cloud-provider/sample/advanced_main.go
+// For more details, please refer to k8s.io/kubernetes/cmd/cloud-controller-manager/main.go
 
 package sample
 
@@ -34,14 +36,18 @@ import (
 	_ "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/klog/v2"
+	// For existing cloud providers, the option to import legacy providers is still available.
+	// e.g. _"k8s.io/legacy-cloud-providers/<provider>"
 )
 
 const (
+	// The variables below are samples, please edit the value for your case.
+
 	// cloudProviderName shows an sample of using hard coded parameter
 	cloudProviderName = "SampleCloudProviderName"
 )
 
-func main() {
+func advancedMain() {
 	rand.Seed(time.Now().UnixNano())
 
 	// cloudProviderConfigFile shows an sample of parse config file from flag option

staging/src/k8s.io/cloud-provider/sample/basic_main.go

@@ -0,0 +1,111 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+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.
+*/
+
+// This file should be written by each cloud provider.
+// For an minimal working example, please refer to k8s.io/cloud-provider/sample/basic_main.go
+// For an advanced example, please refer to k8s.io/cloud-provider/sample/advanced_main.go
+// For more details, please refer to k8s.io/kubernetes/cmd/cloud-controller-manager/main.go
+
+package sample
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/spf13/pflag"
+	"k8s.io/cloud-provider"
+	"k8s.io/cloud-provider/app"
+	"k8s.io/cloud-provider/options"
+	"k8s.io/component-base/cli/flag"
+	"k8s.io/component-base/logs"
+	_ "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/klog/v2"
+	// For existing cloud providers, the option to import legacy providers is still available.
+	// e.g. _"k8s.io/legacy-cloud-providers/<provider>"
+)
+
+const (
+	// The variables below are samples, please edit the value for your case.
+
+	// sampleCloudProviderName shows an sample of using hard coded parameter for CloudProviderName
+	sampleCloudProviderName = "SampleCloudProviderName"
+	// sampleCloudProviderConfigFile shows an sample of using hard coded parameter for CloudProviderConfigFile
+	sampleCloudProviderConfigFile = "sampleCloudProviderConfigFile"
+)
+
+func main() {
+	rand.Seed(time.Now().UnixNano())
+
+	s, err := options.NewCloudControllerManagerOptions()
+	if err != nil {
+		klog.Fatalf("unable to initialize command options: %v", err)
+	}
+	c, err := s.Config([]string{}, app.ControllersDisabledByDefault.List())
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%v\n", err)
+		os.Exit(1)
+	}
+
+	// initialize cloud provider with the cloud provider name and config file provided
+	cloud, err := cloudprovider.InitCloudProvider(sampleCloudProviderName, sampleCloudProviderConfigFile)
+	if err != nil {
+		klog.Fatalf("Cloud provider could not be initialized: %v", err)
+	}
+	if cloud == nil {
+		klog.Fatalf("cloud provider is nil")
+	}
+
+	if !cloud.HasClusterID() {
+		if c.ComponentConfig.KubeCloudShared.AllowUntaggedCloud {
+			klog.Warning("detected a cluster without a ClusterID.  A ClusterID will be required in the future.  Please tag your cluster to avoid any future issues")
+		} else {
+			klog.Fatalf("no ClusterID found.  A ClusterID is required for the cloud provider to function properly.  This check can be bypassed by setting the allow-untagged-cloud option")
+		}
+	}
+
+	// Initialize the cloud provider with a reference to the clientBuilder
+	cloud.Initialize(c.ClientBuilder, make(chan struct{}))
+	// Set the informer on the user cloud object
+	if informerUserCloud, ok := cloud.(cloudprovider.InformerUser); ok {
+		informerUserCloud.SetInformers(c.SharedInformers)
+	}
+
+	controllerInitializers := app.DefaultControllerInitializers(c.Complete(), cloud)
+	command := app.NewCloudControllerManagerCommand(s, c, controllerInitializers)
+
+	// TODO: once we switch everything over to Cobra commands, we can go back to calling
+	// utilflag.InitFlags() (by removing its pflag.Parse() call). For now, we have to set the
+	// normalize func and add the go flag set by hand.
+	// Here is an sample
+	pflag.CommandLine.SetNormalizeFunc(flag.WordSepNormalizeFunc)
+	// utilflag.InitFlags()
+	logs.InitLogs()
+	defer logs.FlushLogs()
+
+	// the flags could be set before execute
+	command.Flags().VisitAll(func(flag *pflag.Flag) {
+		if flag.Name == "cloud-provider" {
+			flag.Value.Set("SampleCloudProviderFlagValue")
+			return
+		}
+	})
+	if err := command.Execute(); err != nil {
+		os.Exit(1)
+	}
+}