三、K8s常见操作命令
1.查看nodes信息：[root@vms201 ~]# kubectl get nodesNAMESTATUSROLESAGEVERSIONvms201.rhce.ccReadycontrol-plane,master15mv1.21.0vms202.rhce.ccReady<none>11mv1.21.0vms203.rhce.c
·
K8s实验环境：
接着上一篇笔记：https://blog.csdn.net/tushanpeipei/article/details/118395393?spm=1001.2014.3001.5502
一个manager，2个worker node的Centos7，保证互相能够通信：
1.查看nodes信息：
[root@vms201 ~]# kubectl get nodes
NAME STATUS ROLES AGE VERSION
vms201.rhce.cc Ready control-plane,master 15m v1.21.0
vms202.rhce.cc Ready <none> 11m v1.21.0
vms203.rhce.cc Ready <none> 11m v1.21.0
[root@vms201 ~]# kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
vms201.rhce.cc Ready control-plane,master 16m v1.21.0 192.168.0.201 <none> CentOS Linux 7 (Core) 3.10.0-693.el7.x86_64 docker://20.10.7
vms202.rhce.cc Ready <none> 12m v1.21.0 192.168.0.202 <none> CentOS Linux 7 (Core) 3.10.0-693.el7.x86_64 docker://20.10.7
vms203.rhce.cc Ready <none> 12m v1.21.0 192.168.0.203 <none> CentOS Linux 7 (Core) 3.10.0-693.el7.x86_64 docker://20.10.7
2.查看集群信息，可以看懂apiservice运行的地址：
[root@vms201 ~]# kubectl cluster-info
Kubernetes control plane is running at https://192.168.0.201:6443
CoreDNS is running at https://192.168.0.201:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
3.查看k8s版本信息：
[root@vms201 ~]# kubectl version
Client Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.0", GitCommit:"cb303e613a121a29364f75cc67d3d580833a7479", GitTreeState:"clean", BuildDate:"2021-04-08T16:31:21Z", GoVersion:"go1.16.1", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.0", GitCommit:"cb303e613a121a29364f75cc67d3d580833a7479", GitTreeState:"clean", BuildDate:"2021-04-08T16:25:06Z", GoVersion:"go1.16.1", Compiler:"gc", Platform:"linux/amd64"}
[root@vms201 ~]# kubectl version --short
Client Version: v1.21.0
Server Version: v1.21.0
client也就是指的是kubectl这个客户端工具的地址。
4.查看初始化集群的设置：
[root@vms201 ~]# kubeadm config view
Command "view" is deprecated, This command is deprecated and will be removed in a future release, please use 'kubectl get cm -o yaml -n kube-system kubeadm-config' to get the kubeadm config directly.
apiServer:
extraArgs:
authorization-mode: Node,RBAC
timeoutForControlPlane: 4m0s
apiVersion: kubeadm.k8s.io/v1beta2
certificatesDir: /etc/kubernetes/pki
clusterName: kubernetes
controllerManager: {}
dns:
type: CoreDNS
etcd:
local:
dataDir: /var/lib/etcd
imageRepository: registry.aliyuncs.com/google_containers
kind: ClusterConfiguration
kubernetesVersion: v1.21.0
networking:
dnsDomain: cluster.local
podSubnet: 10.244.0.0/16
serviceSubnet: 10.96.0.0/12
scheduler: {}
5.查看kubecconfig（认证文件）文件的结构：
[root@vms201 ~]# kubectl config view
apiVersion: v1
clusters:
- cluster:
certificate-authority-data: DATA+OMITTED
server: https://192.168.0.201:6443
name: kubernetes
contexts:
- context:
cluster: kubernetes
user: kubernetes-admin
name: kubernetes-admin@kubernetes
current-context: kubernetes-admin@kubernetes
kind: Config
preferences: {}
users:
- name: kubernetes-admin
user:
client-certificate-data: REDACTED
client-key-data: REDACTED
6.查看节点信息：-n是指定了命名空间，默认k8s组件的pod是在kube-system命名空间下。
[root@vms201 ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
calico-kube-controllers-78d6f96c7b-k5srp 1/1 Running 0 16m
calico-node-hstwf 1/1 Running 0 16m
calico-node-ldfhc 1/1 Running 0 16m
calico-node-sdvzv 1/1 Running 0 16m
coredns-545d6fc579-596hb 1/1 Running 0 25m
coredns-545d6fc579-7mb9v 1/1 Running 0 25m
etcd-vms201.rhce.cc 1/1 Running 0 26m
kube-apiserver-vms201.rhce.cc 1/1 Running 1 26m
kube-controller-manager-vms201.rhce.cc 1/1 Running 0 26m
kube-proxy-28x9h 1/1 Running 0 25m
kube-proxy-7qzdd 1/1 Running 0 22m
kube-proxy-m9c2c 1/1 Running 0 22m
kube-scheduler-vms201.rhce.cc 1/1 Running 0 26m
[root@vms201 ~]# kubectl get pods -n kube-system -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
calico-kube-controllers-78d6f96c7b-k5srp 1/1 Running 0 16m 10.244.58.193 vms202.rhce.cc <none> <none>
calico-node-hstwf 1/1 Running 0 16m 192.168.0.201 vms201.rhce.cc <none> <none>
calico-node-ldfhc 1/1 Running 0 16m 192.168.0.203 vms203.rhce.cc <none> <none>
calico-node-sdvzv 1/1 Running 0 16m 192.168.0.202 vms202.rhce.cc <none> <none>
coredns-545d6fc579-596hb 1/1 Running 0 26m 10.244.20.194 vms201.rhce.cc <none> <none>
coredns-545d6fc579-7mb9v 1/1 Running 0 26m 10.244.20.193 vms201.rhce.cc <none> <none>
etcd-vms201.rhce.cc 1/1 Running 0 26m 192.168.0.201 vms201.rhce.cc <none> <none>
kube-apiserver-vms201.rhce.cc 1/1 Running 1 26m 192.168.0.201 vms201.rhce.cc <none> <none>
kube-controller-manager-vms201.rhce.cc 1/1 Running 0 26m 192.168.0.201 vms201.rhce.cc <none> <none>
kube-proxy-28x9h 1/1 Running 0 26m 192.168.0.201 vms201.rhce.cc <none> <none>
kube-proxy-7qzdd 1/1 Running 0 22m 192.168.0.202 vms202.rhce.cc <none> <none>
kube-proxy-m9c2c 1/1 Running 0 22m 192.168.0.203 vms203.rhce.cc <none> <none>
kube-scheduler-vms201.rhce.cc 1/1 Running 0 26m 192.168.0.201 vms201.rhce.cc <none> <none>
7.查看node或者pod的负载信息
前提：安装metric server
curl -Ls https://api.github.com/repos/kubernetes-sigs/metrics-server/tarball/v0.3.6 -o metrics-server-v0.3.6.tar.gz
# 拷贝镜像到2个worker node
scp metrics-img.tar vms202:~
scp metrics-img.tar vms203:~
在三台设备上加载镜像：
docker load -i metric-img.tar
在master上解压：
rar zxvf metrics-server-v0.36.tar.gz
修改文件：
cd /root/kubernetes-sigs-metrics-server-d1f4f6f/deploy/1.8+/
vim metrics-server-deployment.yaml
需要修改的内容如下：
containers:
- name: metrics-server
image: k8s.gcr.io/metrics-server-amd64:v0.3.6
imagePullPolicy: IfNotPresent
command:
- /metrics-server
- --metric-resolution=30s
- --kubelet-insecure-tls
- --kubelet-preferred-address-types=InternalIP
应用安装当前目录所有yaml文件：
kubectl apply -f .
查看是否安装成功：
[root@vms201 1.8+]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
calico-kube-controllers-78d6f96c7b-k5srp 1/1 Running 0 119m
calico-node-hstwf 1/1 Running 0 119m
calico-node-ldfhc 1/1 Running 0 119m
calico-node-sdvzv 1/1 Running 0 119m
coredns-545d6fc579-596hb 1/1 Running 0 129m
coredns-545d6fc579-7mb9v 1/1 Running 0 129m
etcd-vms201.rhce.cc 1/1 Running 0 129m
kube-apiserver-vms201.rhce.cc 1/1 Running 1 129m
kube-controller-manager-vms201.rhce.cc 1/1 Running 0 129m
kube-proxy-28x9h 1/1 Running 0 129m
kube-proxy-7qzdd 1/1 Running 0 125m
kube-proxy-m9c2c 1/1 Running 0 125m
kube-scheduler-vms201.rhce.cc 1/1 Running 0 129m
metrics-server-bcfb98c76-x8c77 1/1 Running 0 96s
可以看到最后一行，已经安装了metrics，状态为running。
查看nodes或pods的负载情况：
[root@vms201 ~]# kubectl top nodes
W0701 23:55:11.334786 54660 top_node.go:119] Using json format to get metrics. Next release will switch to protocol-buffers, switch early by passing --use-protocol-buffers flag
NAME CPU(cores) CPU% MEMORY(bytes) MEMORY%
vms201.rhce.cc 172m 8% 1442Mi 50%
vms202.rhce.cc 61m 3% 616Mi 21%
vms203.rhce.cc 60m 3% 645Mi 22%
[root@vms201 ~]# kubectl top pods -n kube-system
W0701 23:56:25.946547 55653 top_pod.go:140] Using json format to get metrics. Next release will switch to protocol-buffers, switch early by passing --use-protocol-buffers flag
NAME CPU(cores) MEMORY(bytes)
calico-kube-controllers-78d6f96c7b-k5srp 2m 20Mi
calico-node-hstwf 21m 83Mi
calico-node-ldfhc 32m 96Mi
calico-node-sdvzv 28m 99Mi
coredns-545d6fc579-596hb 2m 14Mi
coredns-545d6fc579-7mb9v 2m 16Mi
etcd-vms201.rhce.cc 7m 55Mi
kube-apiserver-vms201.rhce.cc 29m 352Mi
kube-controller-manager-vms201.rhce.cc 9m 58Mi
kube-proxy-28x9h 1m 18Mi
kube-proxy-7qzdd 1m 19Mi
kube-proxy-m9c2c 1m 19Mi
kube-scheduler-vms201.rhce.cc 2m 24Mi
metrics-server-bcfb98c76-x8c77 1m 12Mi
查看pods的情况，其中CPU一栏的m表示微核心数，一个核心，有1000个微核心。
8.命名空间相关操作
不同命名空间之前相互隔离，每一个pod只能属于一个命名空间。
在master上查看所有的命名空间：
[root@vms201 ~]# kubectl get ns
NAME STATUS AGE
default Active 3h3m
kube-node-lease Active 3h3m
kube-public Active 3h3m
kube-system Active 3h3m
创建命名空间ns1：
[root@vms201 ~]# kubectl create ns ns1
namespace/ns1 created
管理命名空间的相关插件：kubens；下载后导入master。
chmod +x kubens
mv kubens /bin/
导入完成后即可使用kubens对命名空间管理。查看当前在那个命名空间：
[root@vms201 bin]# kubens
default 《-----在此
kube-node-lease
kube-public
kube-system
ns1
切换到kube-system中：
[root@vms201 bin]# kubens kube-system
Context "kubernetes-admin@kubernetes" modified.
Active namespace is "kube-system".
查看当前命名空间下的pods，不用再跟-n指定命名空间：
[root@vms201 bin]# kubectl get pods
NAME READY STATUS RESTARTS AGE
calico-kube-controllers-78d6f96c7b-k5srp 1/1 Running 0 3h7m
calico-node-hstwf 1/1 Running 0 3h7m
calico-node-ldfhc 1/1 Running 0 3h7m
calico-node-sdvzv 1/1 Running 0 3h7m
coredns-545d6fc579-596hb 1/1 Running 0 3h16m
coredns-545d6fc579-7mb9v 1/1 Running 0 3h16m
etcd-vms201.rhce.cc 1/1 Running 0 3h17m
kube-apiserver-vms201.rhce.cc 1/1 Running 1 3h17m
kube-controller-manager-vms201.rhce.cc 1/1 Running 0 3h17m
kube-proxy-28x9h 1/1 Running 0 3h16m
kube-proxy-7qzdd 1/1 Running 0 3h13m
kube-proxy-m9c2c 1/1 Running 0 3h13m
kube-scheduler-vms201.rhce.cc 1/1 Running 0 3h17m
metrics-server-bcfb98c76-x8c77 1/1 Running 0 69m
9.master管理多套集群
当存在多套集群的时候，如果想从一个集群的master上直接管理另外一套集群。需要进入如下操作：
在第一套集群的master上：
cd ~/.kube
vim config
修改内容：
apiVersion: v1
clusters:
# 第一个集群
- cluster:
certificate-authority-data: xxx1
server: https://192.168.0.201:6443
name: kubernetes1
# 设置第二个集群，server为第二个集群的地址
- cluster:
certificate-authority-data: xxx2
server: https://192.168.0.211:6443
name: kubernetes2
contexts:
# 关联第一个集群与用户
- context:
cluster: kubernetes1
namespace: kube-system
user: kubernetes-admin1
name: kubernetes-admin1@kubernetes
# 增加第二个context，将第二个集群与永久关联起来
- context:
cluster: kubernetes2
namespace: kube-system
user: kubernetes-admin2
name: kubernetes-admin2@kubernetes
current-context: kubernetes-admin1@kubernetes
kind: Config
preferences: {}
users:
# 设置两个集群的用户
- name: kubernetes-admin1
user:
client-certificate-data: yyy1
client-key-data: xxx1
- name: kubernetes-admin2
user:
client-certificate-data: yyy2
client-key-data: xxx2
其中第二个集群的认证信息，登陆其master用同样的方法查看即可，然后填入上述的文件中。在第一套集群的master上查看集群连接：
kubect config get-contexts
切换到第二套集群中执行操作：
kubectl config use-context kubernetes2
整理资料来源：
《老段CKA课程》
K8S/Kubernetes社区为您提供最前沿的新闻资讯和知识内容
更多推荐
0
0- 0
已为社区贡献30条内容
所有评论(0)