kubectl get pods --all-namespaces -o custom-columns=NS:.metadata.namespace,NAME:.metadata.name,"CPU(requests)":.spec.containers[*].resources.requests.cpu,"CPU(limits)":.spec.containers[*].resources.limits.cpu,"MEMORY(requests)":.spec.containers[*].resources.requests.memory,"MEMORY(limits)":.spec.containers[*].resources.limits.memory
日志查看
kubectl logs 用于显示 pod 运行中，容器内程序输出到标准输出的内容。跟 docker 的 logs 命令类似。
# Return snapshot logs from pod nginx with only one container
kubectl logs nginx
# Return snapshot of previous terminated ruby container logs from pod web-1
kubectl logs -p -c ruby web-1
# Begin streaming the logs of the ruby container in pod web-1
kubectl logs -f -c ruby web-1
注：kubectl 只可以查看单个容器的日志，如果想要同时查看多个 Pod 的日志，可以使用 stern。比如： stern --all-namespaces -l run=nginx。
# Get output from running pod 123456-7890, using the first container by default
kubectl attach 123456-7890
# Get output from ruby-container from pod 123456-7890
kubectl attach 123456-7890 -c ruby-container
# Switch to raw terminal mode, sends stdin to 'bash' in ruby-container from pod 123456-7890
# and sends stdout/stderr from 'bash' back to the client
kubectl attach 123456-7890 -c ruby-container -i -t
Options:
-c, --container='': Container name. If omitted, the first container in the pod will be chosen
-i, --stdin=false: Pass stdin to the container
-t, --tty=false: Stdin is a TTY
多容器 Pod 可通过 kubectl.kubernetes.io/default-container annotation 配置 kubectl 命令的默认容器。
# Get output from running 'date' from pod 123456-7890, using the first container by default
kubectl exec 123456-7890 date
# Get output from running 'date' in ruby-container from pod 123456-7890
kubectl exec 123456-7890 -c ruby-container date
# Switch to raw terminal mode, sends stdin to 'bash' in ruby-container from pod 123456-7890
# and sends stdout/stderr from 'bash' back to the client
kubectl exec 123456-7890 -c ruby-container -i -t -- bash -il
Options:
-c, --container='': Container name. If omitted, the first container in the pod will be chosen
-p, --pod='': Pod name
-i, --stdin=false: Pass stdin to the container
-t, --tty=false: Stdin is a TT
端口转发
kubectl port-forward 用于将本地端口转发到指定的 Pod。
# Listen on ports 5000 and 6000 locally, forwarding data to/from ports 5000 and 6000 in the pod
kubectl port-forward mypod 5000 6000
# Listen on port 8888 locally, forwarding to 5000 in the pod
kubectl port-forward mypod 8888:5000
# Listen on a random port locally, forwarding to 5000 in the pod
kubectl port-forward mypod :5000
# Listen on a random port locally, forwarding to 5000 in the pod
kubectl port-forward mypod 0:5000
也可以将本地端口转发到服务、复制控制器或者部署的端口。
# Forward to deployment
kubectl port-forward deployment/redis-master 6379:6379
# Forward to replicaSet
kubectl port-forward rs/redis-master 6379:6379
# Forward to service
kubectl port-forward svc/redis-master 6379:6379
API Server 代理
kubectl proxy 命令提供了一个 Kubernetes API 服务的 HTTP 代理。
$ kubectl proxy --port=8080
Starting to serve on 127.0.0.1:8080
可以通过代理地址 http://localhost:8080/api/ 来直接访问 Kubernetes API，比如查询 Pod 列表
# Copy /tmp/foo_dir local directory to /tmp/bar_dir in a remote pod in the default namespace
kubectl cp /tmp/foo_dir <some-pod>:/tmp/bar_dir
# Copy /tmp/foo local file to /tmp/bar in a remote pod in a specific container
kubectl cp /tmp/foo <some-pod>:/tmp/bar -c <specific-container>
# Copy /tmp/foo local file to /tmp/bar in a remote pod in namespace <some-namespace>
kubectl cp /tmp/foo <some-namespace>/<some-pod>:/tmp/bar
# Copy /tmp/foo from a remote pod to /tmp/bar locally
kubectl cp <some-namespace>/<some-pod>:/tmp/foo /tmp/bar
Options:
-c, --container='': Container name. If omitted, the first container in the pod will be chosen
注意：文件拷贝依赖于 tar 命令，所以容器中需要能够执行 tar 命令
kubectl drain
kubectl drain NODE [Options]
它会删除该 NODE 上由 ReplicationController, ReplicaSet, DaemonSet, StatefulSet or Job 创建的 Pod
# Check to see if I can create pods in any namespace
kubectl auth can-i create pods --all-namespaces
# Check to see if I can list deployments in my current namespace
kubectl auth can-i list deployments.extensions
# Check to see if I can do everything in my current namespace ("*" means all)
kubectl auth can-i '*' '*'
# Check to see if I can get the job named "bar" in namespace "foo"
kubectl auth can-i list jobs.batch/bar -n foo
kubectl auth reconcile 自动修复有问题的 RBAC 策略，如
# Reconcile rbac resources from a file
kubectl auth reconcile -f my-rbac-rules.yaml
