通过命令学习k8s

1、kubectl 命令可以列出所有命令

2、kubectl version 命令可以查看版本号

3、kubectl cluster-info命令可以查看集群信息 （192.168.218.136:6443 即为kube-apiserver的IP和端口。）

root@k8s-master \~\]# kubectl cluster-info Kubernetes master is running at https://192.168.218.136:6443 KubeDNS is running at https://192.168.218.136:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'. **4、也可以通过 用户主目录下的.kube/config文件查看集群信息** 用户主目录下的.kube/config \[root@k8s-master \~\]# cat .kube/config apiVersion: v1 clusters: - cluster: certificate-authority-data: LS0tLS1CRUdJTiBDRVJUSUZJQ0FUR...0VSVElGSUNBVEUtLS0tLQo= server: https://192.168.218.136:6443 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: LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCk1J....BVEUtLS0tLQo= client-key-data: LS0tLS1CRUdJTiBSU0EgUFJJVkFURSBLRVktLS...QVRFIEtFWS0tLS0tCg== **5、还可以通过config view命令查看配置** \[root@k8s-master \~\]# kubectl config view apiVersion: v1 clusters: - cluster: certificate-authority-data: DATA+OMITTED server: https://192.168.218.136:6443 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 ---然后可以通过curl访问 api server api接口。 也可以使用 10中的proxy访问api接口。 curl -k https://192.168.218.136:6443 --cert /etc/kubernetes/pki/apiserver-kubelet-client.crt --key /etc/kubernetes/pki/apiserver-kubelet-client.key **6、通过kubectl get node 查看节点信息 7、可通过kubectl get ns 拆开所有命名空间 8、通过kubectl get pod -A 查看所有命名空间下的pod 9、通过kubectl get svc-A 查看所有命名空间下的svc 10、kubectl proxy 命令开启代理** \[root@k8s-master \~\]# **kubectl proxy --port=8080** Starting to serve on 127.0.0.1:8080 **11、通过proxy http接口访问k8s** \[root@k8s-master \~\]# curl 127.0.0.1:8080 { "paths": \[ "/api", "/api/v1", "/apis", "/apis/", "/apis/apps", "/apis/apps/v1", "/apis/autoscaling", "/apis/autoscaling/v1", "/apis/autoscaling/v2beta1", "/apis/autoscaling/v2beta2", "/apis/batch", "/apis/batch/v1", "/apis/extensions", "/apis/extensions/v1beta1", "/apis/networking.k8s.io", "/apis/networking.k8s.io/v1", "/apis/networking.k8s.io/v1beta1", "/apis/node.k8s.io", "/apis/node.k8s.io/v1beta1", "/apis/policy", "/apis/policy/v1beta1", "/healthz", "/healthz/autoregister-completion", "/healthz/etcd", "/healthz/log", "/healthz/ping", "/livez", "/livez/autoregister-completion", "/livez/etcd", "/livez/log", "/livez/ping", "/logs", "/metrics", "/openapi/v2", "/readyz", "/readyz/autoregister-completion", "/readyz/etcd", "/readyz/log", "/readyz/ping", "/readyz/shutdown", "/version" ...... \[root@k8s-master \~\]# curl 127.0.0.1:8080/livez/ping ok \[root@k8s-master \~\]# curl 127.0.0.1:8080/version { "major": "1", "minor": "18", "gitVersion": "v1.18.0", "gitCommit": "9e991415386e4cf155a24b1da15becaa390438d8", "gitTreeState": "clean", "buildDate": "2020-03-25T14:50:46Z", "goVersion": "go1.13.8", "compiler": "gc", "platform": "linux/amd64" } \[root@k8s-master \~\]# curl 127.0.0.1:8080/healthz ok \[root@k8s-master \~\]# curl 127.0.0.1:8080/healthz/etcd ok \[root@k8s-master \~\]# curl 127.0.0.1:8080/healthz/log ok \[root@k8s-master \~\]# curl 127.0.0.1:8080/api { "kind": "APIVersions", "versions": \[ "v1" \], "serverAddressByClientCIDRs": \[ { "clientCIDR": "0.0.0.0/0", "serverAddress": "192.168.218.136:6443" }

}

root@k8s-master \~\]# curl 127.0.0.1:8080/api/v1 { "kind": "APIResourceList", "groupVersion": "v1", "resources": \[ { "name": "bindings", "singularName": "", "namespaced": true, "kind": "Binding", "verbs": \[ "create"

{

"name": "componentstatuses",

"singularName": "",

"namespaced": false,

"kind": "ComponentStatus",

"verbs": [

"get",

"list"

"shortNames": [

"cs"

]

curl 127.0.0.1:8080/api/v1/pods --查看所有pods
curl 127.0.0.1:8080/api/v1/namespaces/kube-system/pods/kube-scheduler-k8s-master --查看某个命名空间下的某个pod

20、kubelet，kube-scheduler-k8s-master、kube-controller-manager-k8s-master、kube-proxy-s8v4t 是如何找到知道kubeapiserver的接口地址的呢？

他们都挂载了自己的配置文件，在 /etc/kubernetes/ 目录下。

其中 admin.conf 会被拷贝到用户家目录下的 .kube/config 文件中。

即cp /etc/kubernetes/admin.conf ~/.kube/config

root@k8s-master \~\]# ll /etc/kubernetes/ -rw------- 1 root root 5451 7月 28 19:38 admin.conf -rw------- 1 root root 5491 7月 28 19:38 **controller-manager.conf** -rw------- 1 root root 1879 7月 28 19:38 **kubelet.conf** drwxr-xr-x 2 root root 113 7月 28 19:38 manifests drwxr-xr-x 3 root root 4096 7月 28 19:38 **pki** -rw------- 1 root root 5439 7月 28 19:38 **scheduler.conf** 另外，**证书文件都放在pki目录下**。 **21、kubeapiserver 也可以开启http端口，这样就不需要证书了。 22、查看日志** kubectl **logs** kube-scheduler-k8s-master -n kube-system kubectl **logs**kube-scheduler-k8s-master -c kube-scheduler -n kube-system **22、proxy的代理功能** curl http://ip:8080/api/v1/proxy/namespace/{namespace}/services/{name} **相当于访问services** **的url** curl http://ip:8080/api/v1/proxy/namespace/{namespace}/pods/{name} **相当于访问pod的url** **23、访问etcd数据库** 登录到k8s的etcd容器中，设置下面的环境变量 export ETCDCTL_ENDPOINTS=https://127.0.0.1:2379 export ETCDCTL_CACERT=/etc/kubernetes/pki/etcd/ca.crt export ETCDCTL_CERT=/etc/kubernetes/pki/etcd/healthcheck-client.crt export ETCDCTL_KEY=/etc/kubernetes/pki/etcd/healthcheck-client.key export ETCDCTL_API=3 然后就可以通过etcdctl命令访问etcd数据库了 etcdctl get /gaofeng/name etcdctl put /gaofeng/name gg etcdctl get --prefix --keys-only / etcdctl get /registry/services/specs/default/kubernetes