kubernetes学习笔记3资源清单

Posted 2022-10-15

kubernetes对象：​

pod|service|replicaset|deployment|statefulset|daemonset|job|cronjob​

服务发现及均衡，service|ingress​

配置与存储，volume|CSI|ComfigMap|Secret|DownwardAPI​

集群级资源，namespace|node|role|ClusterRole|RoleBinding|ClusterRoleBinding​

源数据型资源，HPA|PodTemplate|LimitRange​

1、命令式资源清单创建资源​

kubectl -h​

create|expose|run|set|explain|get|edit|delete #basic commands​

rollout|scale|autoscale #deploy commands​

certificate|cluster-info|top|cordon|uncordon|drain|taint #cluster management，drain排干模式，taint污点，与高级调度相关，能容忍某个污点的节点任务能调度上来，否则不行，如master上有很多污点，创建的pod不会在master上，默认pod不能容忍master的污点，所以master只干controller-manager|etcd|api-server|scheduler这4个重要功能​

describe|logs|attach|exec|port-forward|proxy|cp|auth #troubleshooting and debugging commands，如kubectl describe node node01.magedu.com​

apply|pathch|replace|wait|convert #advanced commands​

label|annotate|completion #settings commands​

alpha|api-resources|api-versions|config|plugin|version #other commands​

kubectl version​

kubectl cluster-info​

kubectl describe node node01.magedu.com​

kubectl run --help #自定义参数，先--，再arg1=value1 arg2=value2​

Usage:​

kubectl run NAME --image=image [--env="key=value"] [--port=port] [--replicas=replicas] [--dry-run=bool] [--overrides=inline-json] [--command] -- [COMMAND] [args...] [options]​

kubectl run nginx-deploy --image=nginx:1.14-alpine --port=80 --replicas=1 #--dry-run=true​

kubectl get deployment​

kubectl get pods -o wide #桥用的是cmi0，10.244.2.x网段​

curl 10.244.2.2 #仅在集群内能访问到，一旦容器异常终止会重新创建并运行，该地址会变掉，所以用pod容器的ip访问不妥当，应该用service地址​

kubectl get pods​

kubectl delete pods nginx-deploy-5b595999-2q6j5 #当容器异常停止后，会重新创建并运行​

kubectl get pod -o wide #​

kubectl describe svc nginx​

kubectl get pods --show-labels​

kubectl edit svc nginx​

kubectl expose -h​

Usage:​

kubectl expose (-f FILENAME | TYPE NAME) [--port=port] [--protocol=TCP|UDP|SCTP] [--target-port=number-or-name] [--name=name] [--external-ip=external-ip-of-service] [--type=type] [options]​

kubectl expose deployment nginx-deploy --name=nginx --port=80 --target-port=80 --protocol=TCP将deployment这个控制器的资源创建为service，service名为nginx​

kubectl get svc #svc同service，仅在集群内可访问，这个地址是被pod客户端访问的，如果要用service名来访问，依赖CoreDNS​

curl 10.98.39.54 #是10.96.0.0/12段的地址​

kubectl get pods -n kube-system -o wide #coredns的地址为10.244.0.2,3​

kubectl get svc -n kube-system #10.96.0.10​

yum -y install bind-utils​

dig -t A nginx @10.96.0.10 #未解析，可能给的A记录信息不完整​

dig -t A nginx.default.svc.cluster.local @10.96.0.10 #在以下busybox运行的容器上查看/etc/resolv.conf完整域名​

kubectl run client --image=busybox --replicas=1 -it --restart=Never​

wget nginx #wget -O - -q http://nginx:80​

wget -O - -q 10.244.1.4​

wget -O - -q 10.244.1.4/hostname.html​

wget -O - -q myapp​

wget -O - -q myapp/hostname.html​

while true; do wget -O - -q myapp/hostname.html; sleep 1; done​

while true; do wget -O - -q myapp; sleep 1; done #显示v1​

kubectl delete svc nginx​

kubectl describe deployment nginx-deploy​

kubectl run myapp --image=ikubernetes/myapp:v1 --replicas=2​

kubectl get deployment -w​

kubectl get pods -o wide​

kubectl expose deployment myapp --name=myapp --port=80​

kubectl get svc​

Usage:​

kubectl scale [--resource-versinotallow=version] [--current-replicas=count] --replicas=COUNT (-f FILENAME | TYPE NAME) [options]​

kubectl scale --replicas=5 deployment myapp扩至5个，自动扩缩容要用到监控​

kubectl get pods​

kubectl scale --replicas=3 deployment myapp #缩至3个​

kubectl get pods myapp-XXXXXX #查看Containers，名字为myapp​

Usage:​

kubectl set image (-f FILENAME | TYPE NAME) CONTAINER_NAME_1=CONTAINER_IMAGE_1 ... CONTAINER_NAME_N=CONTAINER_IMAGE_N [options]​

kubectl set image deployment myapp myapp=ikubernetes/myapp:v2灰度更新​

Usage:​

kubectl rollout history (TYPE NAME | TYPE/NAME) [flags] [options]​

Usage:​

kubectl rollout status (TYPE NAME | TYPE/NAME) [flags] [options]​

Usage:​

kubectl rollout undo (TYPE NAME | TYPE/NAME) [flags] [options]​

kubectl rollout status deployment myapp​

kubectl get pods​

kubectl describe pods​

kubectl rollout undo deployment myapp回滚，默认至上个版本​

iptables -t nat -vLn​

Usage:​

kubectl edit (RESOURCE/NAME | -f FILENAME) [options]​

kubectl edit svc myapp改为type: NodePort​

kubectl get svc #多了80:30020/TCP，30020端口​

在集群外访问，172.20.0.66:30020/hostname.html​

2、声明式资源清单创建资源​

可随时复用；​

kubectl get pod myapp-848bXXX -o yaml​

apiVersion: v1 #所属群组，格式group/version，省group则表示是core组​

kind: Pod #具体的资源对象​

metadata:​

spec: #specification规格，重要，目标状态（用户期望的状态）​

containers:​

tolerations:​

status: #当前状态，应无限接近目标状态​

apiserver仅接收json格式的资源定义；​

用yaml格式提供配置清单，apiserver可自动将其转为json格式，而后再提交；​

资源的配置清单，5部分组成：​

apiVersion #所属群组，获取所有群组kubectl api-versions，alpha-->beta-->canary-->stable​

kind #资源类别​

metadata #元数据，name同一类别下资源名称必须唯一，namespace，name受限于namespace，labels，annotations资源注解，selfLink每个资源的引用PATH为/api/group/VERSION/namespaces/NAMESPACE/TYPE/NAME​

spec #期望的状态，disired state​

status #current state当前状态，由kubernetes集群维护​

kubectl explain pods #注意类型string|object​

kubectl explain pods.metadata​

mkdir mainfests​

cd mainfests​

vim pod-demo.yaml​

apiVersion: v1​

kind: Pod​

metadata:​

name: pod-demo​

namespace: default​

labels:​

app: myapp​

tier: frontend​

annotations:​

magedu.com/created-by: "cluster admin"​

spec:​

containers:​

- name: myapp​

image: ikubernetes/myapp:v1​

ports:​

- name: http​

containerPort: 80​

- name: https​

containerPort: 443​

- name: busybox​

image: busybox:latest​

imagePullPolicy: IfNotPresent​

或command: ["/bin/sh","-c","echo $(date) >> /usr/share/nginx/html/index.html; sleep 5"]，2容器间的存储卷是自己的，不能这样测试​

- "bin/sh"​

- "-c"​

- "sleep 3600"​

nodeSelector:​

只运行在指定标签的节点上​

kubectl create -f pod-demo.yaml​

kubectl get pods​

kubectl describe pods pod-demo​

kubectl get pods​

kubectl logs pod-demo myapp​

curl 10.244.2.10​

Usage:​

kubectl logs [-f] [-p] (POD | TYPE/NAME) [-c CONTAINER] [options]​

kubectl logs pod-demo busybox​

Usage:​

kubectl exec (POD | TYPE/NAME) [-c CONTAINER] [flags] -- COMMAND [args...] [options]​

kubectl exec -it pod-demo -c myapp -- /bin/sh #​

kubectl delete pods pod-demo​

kubectl delete -f pod-demo.yaml #通过配置清单删除资源​