在 Python 中向 GKE 主服务器进行身份验证

Question

我需要使用Kubernetes Python 客户端和 Google Cloud python 客户端对在GKE 中配置的 Kubernetes 集群进行身份验证。我宁愿不掏钱，原因有几个：gcloud

• gcloud当我拥有原生 Google Cloud 库时依赖Python 脚本中的系统 shell是不优雅的
• 它要求系统具有 gcloud
• 我必须将用户切换到相关的 ServiceAccount 并切换回来
• 它会产生启动/加入另一个进程的成本

因此，gcloud container clusters get-credentials（委托给gcloud config config-helper）的工作流程不足以让我获得所需的 API 密钥。如何使用 Google Cloud Python API 获得等效输出？

这是我到目前为止所拥有的：

import kubernetes.client
import googleapiclient.discovery
import base64

# get the cluster object from GKE
gke = googleapiclient.discovery.build('container', 'v1', credentials=config['credentials'])
name = f'projects/{config["project_id"]}/locations/{config["location"]}/{parent}/clusters/{config["name"]}'
gke_clusters = gke.projects().locations().clusters()
gke_cluster = gke_clusters.get(name=name).execute()

# set up Kubernetes Config
kube_config = kubernetes.client.Configuration()
kube_config.host = 'https://{0}/'.format(gke_cluster['endpoint'])
kube_config.verify_ssl = True
#kube_config.api_key['authenticate'] = "don't know what goes here"

# regretably, the Kubernetes client requires `ssl_ca_cert` to be a path, not the literal cert, so I will write it here.
kube_config.ssl_ca_cert = 'ssl_ca_cert'
with open(kube_config.ssl_ca_cert, 'wb') as f:
    f.write(base64.decodestring(gke_cluster['masterAuth']['clusterCaCertificate'].encode()))

# use Kubernetes client to do something
kube_client = kubernetes.client.ApiClient(configuration=kube_config)
kube_v1 = kubernetes.client.CoreV1Api(kube_client)
kube_v1.list_pod_for_all_namespaces(watch=False)

Answer 1

下面是一个从 googleapiclient 中提取访问令牌的解决方案，而不是手动复制粘贴内容。

import googleapiclient.discovery
from tempfile import NamedTemporaryFile
import kubernetes
import base64

def token(*scopes):
    credentials = googleapiclient._auth.default_credentials()
    scopes = [f'https://www.googleapis.com/auth/{s}' for s in scopes]
    scoped = googleapiclient._auth.with_scopes(credentials, scopes)
    googleapiclient._auth.refresh_credentials(scoped)
    return scoped.token

def kubernetes_api(cluster):
    config = kubernetes.client.Configuration()
    config.host = f'https://{cluster["endpoint"]}'

    config.api_key_prefix['authorization'] = 'Bearer'
    config.api_key['authorization'] = token('cloud-platform')

    with NamedTemporaryFile(delete=False) as cert:
        cert.write(base64.decodebytes(cluster['masterAuth']['clusterCaCertificate'].encode()))
        config.ssl_ca_cert = cert.name

    client = kubernetes.client.ApiClient(configuration=config)
    api = kubernetes.client.CoreV1Api(client)

    return api

def run(cluster):
    """You'll need to give whichever account `googleapiclient` is using the 
    'Kubernetes Engine Developer' role so that it can access the Kubernetes API.

    `cluster` should be the dict you get back from `projects.zones.clusters.get`
    and the like"""

    api = kubernetes_api(cluster)
    print(api.list_pod_for_all_namespaces())

弄清楚这一点所花的时间比我愿意承认的要长。@Ivan 的帖子很有帮助。