| title | weight | catalog | date | subtitle | header-img | tags | catagories | |||
|---|---|---|---|---|---|---|---|---|---|---|
client-go的使用及源码分析 |
1 |
true |
2017-12-16 13:02:24 -0800 |
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client-go是一个调用kubernetes集群资源对象API的客户端，即通过client-go实现对kubernetes集群中资源对象（包括deployment、service、ingress、replicaSet、pod、namespace、node等）的增删改查等操作。大部分对kubernetes进行前置API封装的二次开发都通过client-go这个第三方包来实现。
client-go官方文档：https://github.com/kubernetes/client-go
git clone https://github.com/huweihuang/client-go.git
cd client-go
#保证本地HOME目录有配置kubernetes集群的配置文件
go run client-go.gopackage main
import (
"flag"
"fmt"
"os"
"path/filepath"
"time"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/clientcmd"
)
func main() {
var kubeconfig *string
if home := homeDir(); home != "" {
kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
} else {
kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
}
flag.Parse()
// uses the current context in kubeconfig
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
panic(err.Error())
}
// creates the clientset
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
panic(err.Error())
}
for {
pods, err := clientset.CoreV1().Pods("").List(metav1.ListOptions{})
if err != nil {
panic(err.Error())
}
fmt.Printf("There are %d pods in the cluster\n", len(pods.Items))
time.Sleep(10 * time.Second)
}
}
func homeDir() string {
if h := os.Getenv("HOME"); h != "" {
return h
}
return os.Getenv("USERPROFILE") // windows
}➜ go run client-go.go
There are 9 pods in the cluster
There are 7 pods in the cluster
There are 7 pods in the cluster
There are 7 pods in the cluster
There are 7 pods in the clusterclient-go源码：https://github.com/kubernetes/client-go
client-go源码目录结构
- The
kubernetespackage contains the clientset to access Kubernetes API. - The
discoverypackage is used to discover APIs supported by a Kubernetes API server. - The
dynamicpackage contains a dynamic client that can perform generic operations on arbitrary Kubernetes API objects. - The
transportpackage is used to set up auth and start a connection. - The
tools/cachepackage is useful for writing controllers.
kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")获取kubernetes配置文件kubeconfig的绝对路径。一般路径为$HOME/.kube/config。该文件主要用来配置本地连接的kubernetes集群。
config内容如下：
apiVersion: v1
clusters:
- cluster:
server: http://<kube-master-ip>:8080
name: k8s
contexts:
- context:
cluster: k8s
namespace: default
user: ""
name: default
current-context: default
kind: Config
preferences: {}
users: []通过参数（master的url或者kubeconfig路径）和BuildConfigFromFlags方法来获取rest.Config对象，一般是通过参数kubeconfig的路径。
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)BuildConfigFromFlags函数源码
k8s.io/client-go/tools/clientcmd/client_config.go
// BuildConfigFromFlags is a helper function that builds configs from a master
// url or a kubeconfig filepath. These are passed in as command line flags for cluster
// components. Warnings should reflect this usage. If neither masterUrl or kubeconfigPath
// are passed in we fallback to inClusterConfig. If inClusterConfig fails, we fallback
// to the default config.
func BuildConfigFromFlags(masterUrl, kubeconfigPath string) (*restclient.Config, error) {
if kubeconfigPath == "" && masterUrl == "" {
glog.Warningf("Neither --kubeconfig nor --master was specified. Using the inClusterConfig. This might not work.")
kubeconfig, err := restclient.InClusterConfig()
if err == nil {
return kubeconfig, nil
}
glog.Warning("error creating inClusterConfig, falling back to default config: ", err)
}
return NewNonInteractiveDeferredLoadingClientConfig(
&ClientConfigLoadingRules{ExplicitPath: kubeconfigPath},
&ConfigOverrides{ClusterInfo: clientcmdapi.Cluster{Server: masterUrl}}).ClientConfig()
}通过*rest.Config参数和NewForConfig方法来获取clientset对象，clientset是多个client的集合，每个client可能包含不同版本的方法调用。
clientset, err := kubernetes.NewForConfig(config)NewForConfig函数就是初始化clientset中的每个client。
k8s.io/client-go/kubernetes/clientset.go
// NewForConfig creates a new Clientset for the given config.
func NewForConfig(c *rest.Config) (*Clientset, error) {
configShallowCopy := *c
...
var cs Clientset
cs.appsV1beta1, err = appsv1beta1.NewForConfig(&configShallowCopy)
...
cs.coreV1, err = corev1.NewForConfig(&configShallowCopy)
...
}k8s.io/client-go/kubernetes/clientset.go
// Clientset contains the clients for groups. Each group has exactly one
// version included in a Clientset.
type Clientset struct {
*discovery.DiscoveryClient
admissionregistrationV1alpha1 *admissionregistrationv1alpha1.AdmissionregistrationV1alpha1Client
appsV1beta1 *appsv1beta1.AppsV1beta1Client
appsV1beta2 *appsv1beta2.AppsV1beta2Client
authenticationV1 *authenticationv1.AuthenticationV1Client
authenticationV1beta1 *authenticationv1beta1.AuthenticationV1beta1Client
authorizationV1 *authorizationv1.AuthorizationV1Client
authorizationV1beta1 *authorizationv1beta1.AuthorizationV1beta1Client
autoscalingV1 *autoscalingv1.AutoscalingV1Client
autoscalingV2beta1 *autoscalingv2beta1.AutoscalingV2beta1Client
batchV1 *batchv1.BatchV1Client
batchV1beta1 *batchv1beta1.BatchV1beta1Client
batchV2alpha1 *batchv2alpha1.BatchV2alpha1Client
certificatesV1beta1 *certificatesv1beta1.CertificatesV1beta1Client
coreV1 *corev1.CoreV1Client
extensionsV1beta1 *extensionsv1beta1.ExtensionsV1beta1Client
networkingV1 *networkingv1.NetworkingV1Client
policyV1beta1 *policyv1beta1.PolicyV1beta1Client
rbacV1 *rbacv1.RbacV1Client
rbacV1beta1 *rbacv1beta1.RbacV1beta1Client
rbacV1alpha1 *rbacv1alpha1.RbacV1alpha1Client
schedulingV1alpha1 *schedulingv1alpha1.SchedulingV1alpha1Client
settingsV1alpha1 *settingsv1alpha1.SettingsV1alpha1Client
storageV1beta1 *storagev1beta1.StorageV1beta1Client
storageV1 *storagev1.StorageV1Client
}clientset实现了以下的Interface，因此可以通过调用以下方法获得具体的client。例如：
pods, err := clientset.CoreV1().Pods("").List(metav1.ListOptions{})clientset的方法集接口
k8s.io/client-go/kubernetes/clientset.go
type Interface interface {
Discovery() discovery.DiscoveryInterface
AdmissionregistrationV1alpha1() admissionregistrationv1alpha1.AdmissionregistrationV1alpha1Interface
// Deprecated: please explicitly pick a version if possible.
Admissionregistration() admissionregistrationv1alpha1.AdmissionregistrationV1alpha1Interface
AppsV1beta1() appsv1beta1.AppsV1beta1Interface
AppsV1beta2() appsv1beta2.AppsV1beta2Interface
// Deprecated: please explicitly pick a version if possible.
Apps() appsv1beta2.AppsV1beta2Interface
AuthenticationV1() authenticationv1.AuthenticationV1Interface
// Deprecated: please explicitly pick a version if possible.
Authentication() authenticationv1.AuthenticationV1Interface
AuthenticationV1beta1() authenticationv1beta1.AuthenticationV1beta1Interface
AuthorizationV1() authorizationv1.AuthorizationV1Interface
// Deprecated: please explicitly pick a version if possible.
Authorization() authorizationv1.AuthorizationV1Interface
AuthorizationV1beta1() authorizationv1beta1.AuthorizationV1beta1Interface
AutoscalingV1() autoscalingv1.AutoscalingV1Interface
// Deprecated: please explicitly pick a version if possible.
Autoscaling() autoscalingv1.AutoscalingV1Interface
AutoscalingV2beta1() autoscalingv2beta1.AutoscalingV2beta1Interface
BatchV1() batchv1.BatchV1Interface
// Deprecated: please explicitly pick a version if possible.
Batch() batchv1.BatchV1Interface
BatchV1beta1() batchv1beta1.BatchV1beta1Interface
BatchV2alpha1() batchv2alpha1.BatchV2alpha1Interface
CertificatesV1beta1() certificatesv1beta1.CertificatesV1beta1Interface
// Deprecated: please explicitly pick a version if possible.
Certificates() certificatesv1beta1.CertificatesV1beta1Interface
CoreV1() corev1.CoreV1Interface
// Deprecated: please explicitly pick a version if possible.
Core() corev1.CoreV1Interface
ExtensionsV1beta1() extensionsv1beta1.ExtensionsV1beta1Interface
// Deprecated: please explicitly pick a version if possible.
Extensions() extensionsv1beta1.ExtensionsV1beta1Interface
NetworkingV1() networkingv1.NetworkingV1Interface
// Deprecated: please explicitly pick a version if possible.
Networking() networkingv1.NetworkingV1Interface
PolicyV1beta1() policyv1beta1.PolicyV1beta1Interface
// Deprecated: please explicitly pick a version if possible.
Policy() policyv1beta1.PolicyV1beta1Interface
RbacV1() rbacv1.RbacV1Interface
// Deprecated: please explicitly pick a version if possible.
Rbac() rbacv1.RbacV1Interface
RbacV1beta1() rbacv1beta1.RbacV1beta1Interface
RbacV1alpha1() rbacv1alpha1.RbacV1alpha1Interface
SchedulingV1alpha1() schedulingv1alpha1.SchedulingV1alpha1Interface
// Deprecated: please explicitly pick a version if possible.
Scheduling() schedulingv1alpha1.SchedulingV1alpha1Interface
SettingsV1alpha1() settingsv1alpha1.SettingsV1alpha1Interface
// Deprecated: please explicitly pick a version if possible.
Settings() settingsv1alpha1.SettingsV1alpha1Interface
StorageV1beta1() storagev1beta1.StorageV1beta1Interface
StorageV1() storagev1.StorageV1Interface
// Deprecated: please explicitly pick a version if possible.
Storage() storagev1.StorageV1Interface
}我们以clientset中的CoreV1Client为例做分析。
通过传入的配置信息rest.Config初始化CoreV1Client对象。
k8s.io/client-go/kubernetes/clientset.go
cs.coreV1, err = corev1.NewForConfig(&configShallowCopy)k8s.io/client-go/kubernetes/typed/core/v1/core_client.go
// NewForConfig creates a new CoreV1Client for the given config.
func NewForConfig(c *rest.Config) (*CoreV1Client, error) {
config := *c
if err := setConfigDefaults(&config); err != nil {
return nil, err
}
client, err := rest.RESTClientFor(&config)
if err != nil {
return nil, err
}
return &CoreV1Client{client}, nil
}corev1.NewForConfig方法本质是调用了rest.RESTClientFor(&config)方法创建RESTClient对象，即CoreV1Client的本质就是一个RESTClient对象。
以下是CoreV1Client结构体的定义：
k8s.io/client-go/kubernetes/typed/core/v1/core_client.go
// CoreV1Client is used to interact with features provided by the group.
type CoreV1Client struct {
restClient rest.Interface
}CoreV1Client实现了CoreV1Interface的接口，即以下方法，从而对kubernetes的资源对象进行增删改查的操作。
k8s.io/client-go/kubernetes/typed/core/v1/core_client.go
//CoreV1Client的方法
func (c *CoreV1Client) ComponentStatuses() ComponentStatusInterface {...}
//ConfigMaps
func (c *CoreV1Client) ConfigMaps(namespace string) ConfigMapInterface {...}
//Endpoints
func (c *CoreV1Client) Endpoints(namespace string) EndpointsInterface {...}
func (c *CoreV1Client) Events(namespace string) EventInterface {...}
func (c *CoreV1Client) LimitRanges(namespace string) LimitRangeInterface {...}
//Namespaces
func (c *CoreV1Client) Namespaces() NamespaceInterface {...}
//Nodes
func (c *CoreV1Client) Nodes() NodeInterface {...}
func (c *CoreV1Client) PersistentVolumes() PersistentVolumeInterface {...}
func (c *CoreV1Client) PersistentVolumeClaims(namespace string) PersistentVolumeClaimInterface {...}
//Pods
func (c *CoreV1Client) Pods(namespace string) PodInterface {...}
func (c *CoreV1Client) PodTemplates(namespace string) PodTemplateInterface {...}
//ReplicationControllers
func (c *CoreV1Client) ReplicationControllers(namespace string) ReplicationControllerInterface {...}
func (c *CoreV1Client) ResourceQuotas(namespace string) ResourceQuotaInterface {...}
func (c *CoreV1Client) Secrets(namespace string) SecretInterface {...}
//Services
func (c *CoreV1Client) Services(namespace string) ServiceInterface {...}
func (c *CoreV1Client) ServiceAccounts(namespace string) ServiceAccountInterface {...}k8s.io/client-go/kubernetes/typed/core/v1/core_client.go
type CoreV1Interface interface {
RESTClient() rest.Interface
ComponentStatusesGetter
ConfigMapsGetter
EndpointsGetter
EventsGetter
LimitRangesGetter
NamespacesGetter
NodesGetter
PersistentVolumesGetter
PersistentVolumeClaimsGetter
PodsGetter
PodTemplatesGetter
ReplicationControllersGetter
ResourceQuotasGetter
SecretsGetter
ServicesGetter
ServiceAccountsGetter
}CoreV1Interface中包含了各种kubernetes对象的调用接口，例如PodsGetter是对kubernetes中pod对象增删改查操作的接口。ServicesGetter是对service对象的操作的接口。
以下我们以PodsGetter接口为例分析CoreV1Client对pod对象的增删改查接口调用。
示例中的代码如下：
pods, err := clientset.CoreV1().Pods("").List(metav1.ListOptions{})CoreV1().Pods()
k8s.io/client-go/kubernetes/typed/core/v1/core_client.go
func (c *CoreV1Client) Pods(namespace string) PodInterface {
return newPods(c, namespace)
}newPods()
k8s.io/client-go/kubernetes/typed/core/v1/pod.go
// newPods returns a Pods
func newPods(c *CoreV1Client, namespace string) *pods {
return &pods{
client: c.RESTClient(),
ns: namespace,
}
}CoreV1().Pods()的方法实际上是调用了newPods()的方法，创建了一个pods对象，pods对象继承了rest.Interface接口，即最终的实现本质是RESTClient的HTTP调用。
k8s.io/client-go/kubernetes/typed/core/v1/pod.go
// pods implements PodInterface
type pods struct {
client rest.Interface
ns string
}pods对象实现了PodInterface接口。PodInterface定义了pods对象的增删改查等方法。
k8s.io/client-go/kubernetes/typed/core/v1/pod.go
// PodInterface has methods to work with Pod resources.
type PodInterface interface {
Create(*v1.Pod) (*v1.Pod, error)
Update(*v1.Pod) (*v1.Pod, error)
UpdateStatus(*v1.Pod) (*v1.Pod, error)
Delete(name string, options *meta_v1.DeleteOptions) error
DeleteCollection(options *meta_v1.DeleteOptions, listOptions meta_v1.ListOptions) error
Get(name string, options meta_v1.GetOptions) (*v1.Pod, error)
List(opts meta_v1.ListOptions) (*v1.PodList, error)
Watch(opts meta_v1.ListOptions) (watch.Interface, error)
Patch(name string, pt types.PatchType, data []byte, subresources ...string) (result *v1.Pod, err error)
PodExpansion
}PodsGetter
PodsGetter继承了PodInterface的接口。
k8s.io/client-go/kubernetes/typed/core/v1/pod.go
// PodsGetter has a method to return a PodInterface.
// A group's client should implement this interface.
type PodsGetter interface {
Pods(namespace string) PodInterface
}Pods().List()
pods.List()方法通过RESTClient的HTTP调用来实现对kubernetes的pod资源的获取。
k8s.io/client-go/kubernetes/typed/core/v1/pod.go
// List takes label and field selectors, and returns the list of Pods that match those selectors.
func (c *pods) List(opts meta_v1.ListOptions) (result *v1.PodList, err error) {
result = &v1.PodList{}
err = c.client.Get().
Namespace(c.ns).
Resource("pods").
VersionedParams(&opts, scheme.ParameterCodec).
Do().
Into(result)
return
}以上分析了clientset.CoreV1().Pods("").List(metav1.ListOptions{})对pod资源获取的过程，最终是调用RESTClient的方法实现。
以下分析RESTClient的创建过程及作用。
RESTClient对象的创建同样是依赖传入的config信息。
k8s.io/client-go/kubernetes/typed/core/v1/core_client.go
client, err := rest.RESTClientFor(&config)k8s.io/client-go/rest/config.go
// RESTClientFor returns a RESTClient that satisfies the requested attributes on a client Config
// object. Note that a RESTClient may require fields that are optional when initializing a Client.
// A RESTClient created by this method is generic - it expects to operate on an API that follows
// the Kubernetes conventions, but may not be the Kubernetes API.
func RESTClientFor(config *Config) (*RESTClient, error) {
...
qps := config.QPS
...
burst := config.Burst
...
baseURL, versionedAPIPath, err := defaultServerUrlFor(config)
...
transport, err := TransportFor(config)
...
var httpClient *http.Client
if transport != http.DefaultTransport {
httpClient = &http.Client{Transport: transport}
if config.Timeout > 0 {
httpClient.Timeout = config.Timeout
}
}
return NewRESTClient(baseURL, versionedAPIPath, config.ContentConfig, qps, burst, config.RateLimiter, httpClient)
}RESTClientFor函数调用了NewRESTClient的初始化函数。
k8s.io/client-go/rest/client.go
// NewRESTClient creates a new RESTClient. This client performs generic REST functions
// such as Get, Put, Post, and Delete on specified paths. Codec controls encoding and
// decoding of responses from the server.
func NewRESTClient(baseURL *url.URL, versionedAPIPath string, config ContentConfig, maxQPS float32, maxBurst int, rateLimiter flowcontrol.RateLimiter, client *http.Client) (*RESTClient, error) {
base := *baseURL
...
serializers, err := createSerializers(config)
...
return &RESTClient{
base: &base,
versionedAPIPath: versionedAPIPath,
contentConfig: config,
serializers: *serializers,
createBackoffMgr: readExpBackoffConfig,
Throttle: throttle,
Client: client,
}, nil
}以下介绍RESTClient的结构体定义，RESTClient结构体中包含了http.Client，即本质上RESTClient就是一个http.Client的封装实现。
k8s.io/client-go/rest/client.go
// RESTClient imposes common Kubernetes API conventions on a set of resource paths.
// The baseURL is expected to point to an HTTP or HTTPS path that is the parent
// of one or more resources. The server should return a decodable API resource
// object, or an api.Status object which contains information about the reason for
// any failure.
//
// Most consumers should use client.New() to get a Kubernetes API client.
type RESTClient struct {
// base is the root URL for all invocations of the client
base *url.URL
// versionedAPIPath is a path segment connecting the base URL to the resource root
versionedAPIPath string
// contentConfig is the information used to communicate with the server.
contentConfig ContentConfig
// serializers contain all serializers for underlying content type.
serializers Serializers
// creates BackoffManager that is passed to requests.
createBackoffMgr func() BackoffManager
// TODO extract this into a wrapper interface via the RESTClient interface in kubectl.
Throttle flowcontrol.RateLimiter
// Set specific behavior of the client. If not set http.DefaultClient will be used.
Client *http.Client
}RESTClient实现了以下的接口方法：
k8s.io/client-go/rest/client.go
// Interface captures the set of operations for generically interacting with Kubernetes REST apis.
type Interface interface {
GetRateLimiter() flowcontrol.RateLimiter
Verb(verb string) *Request
Post() *Request
Put() *Request
Patch(pt types.PatchType) *Request
Get() *Request
Delete() *Request
APIVersion() schema.GroupVersion
}在调用HTTP方法（Post()，Put()，Get()，Delete() ）时，实际上调用了Verb(verb string)函数。
k8s.io/client-go/rest/client.go
// Verb begins a request with a verb (GET, POST, PUT, DELETE).
//
// Example usage of RESTClient's request building interface:
// c, err := NewRESTClient(...)
// if err != nil { ... }
// resp, err := c.Verb("GET").
// Path("pods").
// SelectorParam("labels", "area=staging").
// Timeout(10*time.Second).
// Do()
// if err != nil { ... }
// list, ok := resp.(*api.PodList)
//
func (c *RESTClient) Verb(verb string) *Request {
backoff := c.createBackoffMgr()
if c.Client == nil {
return NewRequest(nil, verb, c.base, c.versionedAPIPath, c.contentConfig, c.serializers, backoff, c.Throttle)
}
return NewRequest(c.Client, verb, c.base, c.versionedAPIPath, c.contentConfig, c.serializers, backoff, c.Throttle)
}Verb函数调用了NewRequest方法，最后调用Do()方法实现一个HTTP请求获取Result。
client-go对kubernetes资源对象的调用，需要先获取kubernetes的配置信息，即$HOME/.kube/config。
整个调用的过程如下：
kubeconfig→rest.config→clientset→具体的client(CoreV1Client)→具体的资源对象(pod)→RESTClient→http.Client→HTTP请求的发送及响应
通过clientset中不同的client和client中不同资源对象的方法实现对kubernetes中资源对象的增删改查等操作，常用的client有CoreV1Client、AppsV1beta1Client、ExtensionsV1beta1Client等。
创建clientset
//获取kubeconfig
kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
//创建config
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
//创建clientset
clientset, err := kubernetes.NewForConfig(config)
//具体的资源调用见以下例子//声明deployment对象
var deployment *v1beta1.Deployment
//构造deployment对象
//创建deployment
deployment, err := clientset.AppsV1beta1().Deployments(<namespace>).Create(<deployment>)
//更新deployment
deployment, err := clientset.AppsV1beta1().Deployments(<namespace>).Update(<deployment>)
//删除deployment
err := clientset.AppsV1beta1().Deployments(<namespace>).Delete(<deployment.Name>, &meta_v1.DeleteOptions{})
//查询deployment
deployment, err := clientset.AppsV1beta1().Deployments(<namespace>).Get(<deployment.Name>, meta_v1.GetOptions{})
//列出deployment
deploymentList, err := clientset.AppsV1beta1().Deployments(<namespace>).List(&meta_v1.ListOptions{})
//watch deployment
watchInterface, err := clientset.AppsV1beta1().Deployments(<namespace>).Watch(&meta_v1.ListOptions{})//声明service对象
var service *v1.Service
//构造service对象
//创建service
service, err := clientset.CoreV1().Services(<namespace>).Create(<service>)
//更新service
service, err := clientset.CoreV1().Services(<namespace>).Update(<service>)
//删除service
err := clientset.CoreV1().Services(<namespace>).Delete(<service.Name>, &meta_v1.DeleteOptions{})
//查询service
service, err := clientset.CoreV1().Services(<namespace>).Get(<service.Name>, meta_v1.GetOptions{})
//列出service
serviceList, err := clientset.CoreV1().Services(<namespace>).List(&meta_v1.ListOptions{})
//watch service
watchInterface, err := clientset.CoreV1().Services(<namespace>).Watch(&meta_v1.ListOptions{})//声明ingress对象
var ingress *v1beta1.Ingress
//构造ingress对象
//创建ingress
ingress, err := clientset.ExtensionsV1beta1().Ingresses(<namespace>).Create(<ingress>)
//更新ingress
ingress, err := clientset.ExtensionsV1beta1().Ingresses(<namespace>).Update(<ingress>)
//删除ingress
err := clientset.ExtensionsV1beta1().Ingresses(<namespace>).Delete(<ingress.Name>, &meta_v1.DeleteOptions{})
//查询ingress
ingress, err := clientset.ExtensionsV1beta1().Ingresses(<namespace>).Get(<ingress.Name>, meta_v1.GetOptions{})
//列出ingress
ingressList, err := clientset.ExtensionsV1beta1().Ingresses(<namespace>).List(&meta_v1.ListOptions{})
//watch ingress
watchInterface, err := clientset.ExtensionsV1beta1().Ingresses(<namespace>).Watch(&meta_v1.ListOptions{})//声明replicaSet对象
var replicaSet *v1beta1.ReplicaSet
//构造replicaSet对象
//创建replicaSet
replicaSet, err := clientset.ExtensionsV1beta1().ReplicaSets(<namespace>).Create(<replicaSet>)
//更新replicaSet
replicaSet, err := clientset.ExtensionsV1beta1().ReplicaSets(<namespace>).Update(<replicaSet>)
//删除replicaSet
err := clientset.ExtensionsV1beta1().ReplicaSets(<namespace>).Delete(<replicaSet.Name>, &meta_v1.DeleteOptions{})
//查询replicaSet
replicaSet, err := clientset.ExtensionsV1beta1().ReplicaSets(<namespace>).Get(<replicaSet.Name>, meta_v1.GetOptions{})
//列出replicaSet
replicaSetList, err := clientset.ExtensionsV1beta1().ReplicaSets(<namespace>).List(&meta_v1.ListOptions{})
//watch replicaSet
watchInterface, err := clientset.ExtensionsV1beta1().ReplicaSets(<namespace>).Watch(&meta_v1.ListOptions{})新版的kubernetes中一般通过deployment来创建replicaSet，再通过replicaSet来控制pod。
//声明pod对象
var pod *v1.Pod
//创建pod
pod, err := clientset.CoreV1().Pods(<namespace>).Create(<pod>)
//更新pod
pod, err := clientset.CoreV1().Pods(<namespace>).Update(<pod>)
//删除pod
err := clientset.CoreV1().Pods(<namespace>).Delete(<pod.Name>, &meta_v1.DeleteOptions{})
//查询pod
pod, err := clientset.CoreV1().Pods(<namespace>).Get(<pod.Name>, meta_v1.GetOptions{})
//列出pod
podList, err := clientset.CoreV1().Pods(<namespace>).List(&meta_v1.ListOptions{})
//watch pod
watchInterface, err := clientset.CoreV1().Pods(<namespace>).Watch(&meta_v1.ListOptions{})//声明statefulset对象
var statefulset *v1.StatefulSet
//创建statefulset
statefulset, err := clientset.AppsV1().StatefulSets(<namespace>).Create(<statefulset>)
//更新statefulset
statefulset, err := clientset.AppsV1().StatefulSets(<namespace>).Update(<statefulset>)
//删除statefulset
err := clientset.AppsV1().StatefulSets(<namespace>).Delete(<statefulset.Name>, &meta_v1.DeleteOptions{})
//查询statefulset
statefulset, err := clientset.AppsV1().StatefulSets(<namespace>).Get(<statefulset.Name>, meta_v1.GetOptions{})
//列出statefulset
statefulsetList, err := clientset.AppsV1().StatefulSets(<namespace>).List(&meta_v1.ListOptions{})
//watch statefulset
watchInterface, err := clientset.AppsV1().StatefulSets(<namespace>).Watch(&meta_v1.ListOptions{}) 通过以上对kubernetes的资源对象的操作函数可以看出，每个资源对象都有增删改查等方法，基本调用逻辑类似。一般二次开发只需要创建deployment、service、ingress三个资源对象即可，pod对象由deployment包含的replicaSet来控制创建和删除。函数调用的入参一般只有NAMESPACE和kubernetesObject两个参数，部分操作有Options的参数。在创建前，需要对资源对象构造数据，可以理解为编辑一个资源对象的yaml文件，然后通过kubectl create -f xxx.yaml来创建对象。
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