python3 kubernetes api的使用示例

时间:2021-01-12 巽逸人气:0

这篇文章主要介绍了python3 kubernetes api的使用示例，帮助大家更好的理解和使用python，感兴趣的朋友可以了解下

一、安装

github：https://github.com/kubernetes-client/python

安装

pip install kubernetes

二、认证

1、kubeconfig文件认证

首先引入SDK支持库。然后将 ~/.kube 的config文件的内容复制到本地目录，保存为文件kubeconfig.yaml，然后运行下面的python代码。

[root@k8s-m ~]# cp .kube/config  kubeconfig.yaml

#使用
from kubernetes import client, config
config.kube_config.load_kube_config(config_file="/root/kubeconfig.yaml")

三、api使用

1、列出资源信息

from kubernetes import client, config
config.kube_config.load_kube_config(config_file="/root/kubeconfig.yaml")

#获取API的CoreV1Api版本对象
v1 = client.CoreV1Api()

#列出 namespaces
for ns in v1.list_namespace().items:
  print(ns.metadata.name)
  
#列出所有的services
ret = v1.list_service_for_all_namespaces(watch=False)
for i in ret.items:
  print("%s \t%s \t%s \t%s \t%s \n" % (i.kind, i.metadata.namespace, i.metadata.name, i.spec.cluster_ip, i.spec.ports ))
  
#列出所有的pod
ret = v1.list_pod_for_all_namespaces(watch=False)
for i in ret.items:
  print("%s\t%s\t%s" % (i.status.pod_ip, i.metadata.namespace, i.metadata.name))

#列出所有deploy
ret = v1.list_deployments_for_all_namespaces(watch=False)
for i in ret.items:
  print("%s\t%s\t%s" % (i.status.pod_ip, i.metadata.namespace, i.metadata.name))
  
##列出其他资源和以上类似，不懂可以查看(kubectl api-resources)

2、创建k8s资源对象

github:https://github.com/kubernetes-client/python/tree/master/examples

创建资源（提前写好yaml资源清单）

#创建deploy
[root@k8s-m ~]# cat create_deploy.py
from os import path
import yaml
from kubernetes import client, config

def main():
  config.load_kube_config()

  with open(path.join(path.dirname(__file__), "/root/deploy.yaml")) as f:
    dep = yaml.safe_load(f)
    k8s_apps_v1 = client.AppsV1Api()
    resp = k8s_apps_v1.create_namespaced_deployment(
      body=dep, namespace="default")
    print("Deployment created. status='%s'" % resp.metadata.name)
main()

[root@k8s-m ~]# kubectl get pod 
NAME            READY  STATUS  RESTARTS  AGE
mydeploy-6946c867dc-bgcld  1/1   Running  0     40s
mydeploy-6946c867dc-rdnvj  1/1   Running  0     40s
[root@k8s-m ~]# kubectl get deploy
NAME    READY  UP-TO-DATE  AVAILABLE  AGE
mydeploy  2/2   2      2      44s


#创建pod例子（其它资源得自己查源码自己找对应的API）
[root@k8s-m ~]# cat create_pod.py 
from os import path

import yaml

from kubernetes import client, config


def main():
  config.load_kube_config()

  with open(path.join(path.dirname(__file__), "/root/pod.yaml")) as f:
    dep = yaml.safe_load(f)
    k8s_core_v1 = client.CoreV1Api()
    resp = k8s_core_v1.create_namespaced_pod(
      body=dep, namespace="default")
    print("Pod created. status='%s'" % resp.metadata.name)


if __name__ == '__main__':
  main()

##
[root@k8s-m ~]# python3 create_pod.py 
Pod created. status='nginx-pod'
[root@k8s-m ~]# kubectl get pod nginx-pod
NAME    READY  STATUS  RESTARTS  AGE
nginx-pod  1/1   Running  0     8s

3、删除资源（我这里展示pod例子，其它资源删除差不多）

参考地址:/usr/local/python3/lib/python3.6/site-packages/kubernetes/client/

[root@k8s-m ~]# cat dp.py
from os import path
import yaml
from kubernetes import client, config

def main():
  config.load_kube_config()
  k8s_core_v1 = client.CoreV1Api()
  resp = k8s_core_v1.delete_namespaced_pod(namespace="default",name='nginx-pod')
  print("delete Pod ")

[root@k8s-m ~]# python3 dp.py
delete Pod

4、查看资源（类似kubectl get pod xxx -o json）

#查看(read)

[root@k8s-m ~]# cat rp.py 
from os import path
import yaml
from kubernetes import client, config

def main():
  config.load_kube_config()
  k8s_core_v1 = client.CoreV1Api()
  resp = k8s_core_v1.read_namespaced_pod(namespace="default",name='nginx-pod')
  print("read Pod ")
  #详细信息
  print(resp)
  #指定信息
  print(resp.spec.containers[0].image)

if __name__ == '__main__':
  main()

[root@k8s-m ~]# python3  rp.py |tail
      'host_ip': '172.31.250.229',
      'init_container_statuses': None,
      'message': None,
      'nominated_node_name': None,
      'phase': 'Running',
      'pod_ip': '10.244.167.134',
      'qos_class': 'BestEffort',
      'reason': None,
      'start_time': datetime.datetime(2019, 8, 30, 9, 13, 49, tzinfo=tzutc())}}
nginx

5、修改

[root@k8s-m ~]# cat pp.py 
from os import path
import yaml
from kubernetes import client, config

def main():
  config.load_kube_config()
  k8s_core_v1 = client.CoreV1Api()
  old_resp = k8s_core_v1.read_namespaced_pod(namespace="default",name='nginx-pod')
  old_resp.spec.containers[0].image = "nginx:alpine"
  #修改镜像
  new_resp = k8s_core_v1.patch_namespaced_pod(namespace="default",name='nginx-pod',body=old_resp)
  print(new_resp.spec.containers[0].image)
if __name__ == '__main__':
  main()

[root@k8s-m ~]# python3 pp.py 
nginx:alpine

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