020.掌握Pod-Pod基础使用

  1 apiversion: v1			#必选，版本号，例如v1,版本号必须可以用 kubectl api-versions 查询到
  2 kind: pod				#必选，pod
  3 metadata:				#必选，元数据
  4   name: string			#必选，pod名称，需符合rfc 1035规范
  5   namespace: string			#必选，pod所属的命名空间，默认为"default"
  6   labels:				#自定义标签
  7     - name: string			#自定义标签名字
  8   annotations:			#自定义注释列表
  9     - name: string
 10 spec:				#必选，pod中容器的详细定义
 11   containers:			#必选，pod中容器列表
 12   - name: string			#必选，容器名称，需符合rfc 1035规范
 13     image: string			#必选，容器的镜像名称
 14     imagepullpolicy: [ always|never|ifnotpresent ]	#获取镜像的策略，alawys表示每次都尝试下载镜像，ifnotpresent表示优先使用本地镜像,否则下载镜像，nerver表示仅使用本地镜像
 15     command: [string]		#容器的启动命令列表，如不指定，使用打包时使用的启动命令
 16     args: [string]			#容器的启动命令参数列表
 17     workingdir: string		#容器的工作目录
 18     volumemounts:			#挂载到容器内部的存储卷配置
 19     - name: string			#引用pod定义的共享存储卷的名称，需用volumes[]部分定义的的卷名
 20       mountpath: string		#存储卷在容器内mount的绝对路径，应少于512字符
 21       readonly: boolean		#是否为只读模式，默认为读写模式
 22     ports:				#需要暴露的端口库号列表
 23     - name: string			#端口的名称
 24       containerport: int		#容器需要监听的端口号
 25       hostport: int		        #容器所在主机需要监听的端口号，默认与container相同
 26       protocol: string		#端口协议，支持tcp和udp，默认tcp
 27     env:				#容器运行前需设置的环境变量列表
 28     - name: string			#环境变量名称
 29       value: string		        #环境变量的值
 30     resources:			#资源限制和请求的设置
 31       limits:			#资源限制的设置
 32         cpu: string		        #cpu的限制，单位为core数，将用于docker run --cpu-shares参数
 33         memory: string		#内存限制，单位可以为mib/gib，将用于docker run --memory参数
 34       requests:			#资源请求的设置
 35         cpu: string		        #cpu请求，容器启动的初始可用数量
 36         memory: string		#内存请求,容器启动的初始可用数量
 37     livenessprobe:			#对pod内各容器健康检查的设置，当探测无响应几次后将自动重启该容器，检查方法有exec、httpget和tcpsocket，对一个容器只需设置其中一种方法即可
 38       exec:			        #对pod容器内检查方式设置为exec方式
 39         command: [string]		#exec方式需要制定的命令或脚本
 40       httpget:			#对pod内个容器健康检查方法设置为httpget，需要制定path、port
 41         path: string
 42         port: number
 43         host: string
 44         scheme: string
 45         httpheaders:
 46         - name: string
 47           value: string
 48       tcpsocket:			#对pod内个容器健康检查方式设置为tcpsocket方式
 49          port: number
 50        initialdelayseconds: 0	#容器启动完成后首次探测的时间，单位为秒
 51        timeoutseconds: 0		#对容器健康检查探测等待响应的超时时间，单位秒，默认1秒
 52        periodseconds: 0		#对容器监控检查的定期探测时间设置，单位秒，默认10秒一次
 53        successthreshold: 0
 54        failurethreshold: 0
 55        securitycontext:
 56          privileged: false
 57     restartpolicy: [always | never | onfailure]	#pod的重启策略，always表示一旦不管以何种方式终止运行，kubelet都将重启，onfailure表示只有pod以非0退出码退出才重启，nerver表示不再重启该pod
 58     nodeselector: obeject		#设置nodeselector表示将该pod调度到包含这个label的node上，以key：value的格式指定
 59     imagepullsecrets:		#pull镜像时使用的secret名称，以key：secretkey格式指定
 60     - name: string
 61     hostnetwork: false		#是否使用主机网络模式，默认为false，如果设置为true，表示使用宿主机网络
 62     volumes:			#在该pod上定义共享存储卷列表
 63     - name: string			#共享存储卷名称 （volumes类型有很多种）
 64       emptydir: {}			#类型为emtydir的存储卷，与pod同生命周期的一个临时目录。为空值
 65       hostpath: string		#类型为hostpath的存储卷，表示挂载pod所在宿主机的目录
 66         path: string		#pod所在宿主机的目录，将被用于同期中mount的目录
 67       secret:			#类型为secret的存储卷，挂载集群与定义的secre对象到容器内部
 68         scretname: string
 69         items:
 70         - key: string
 71           path: string
 72       configmap:			#类型为configmap的存储卷，挂载预定义的configmap对象到容器内部
 73         name: string
 74         items:
 75         - key: string
 76           path: string

  1 [root@k8smaster01 study]# vi frontend-localredis-pod.yaml
  2 apiversion: v1
  3 kind: pod
  4 metadata:
  5   name: redis-php
  6   label:
  7     name: redis-php
  8 spec:
  9   containers:
 10   - name: frontend
 11     image: kubeguide/guestbook-php-frontend:localredis
 12     ports:
 13     - containersport: 80
 14   - name: redis-php
 15     image: kubeguide/redis-master
 16     ports:
 17     - containersport: 6379
 18 
 19 [root@k8smaster01 study]# kubectl create -f frontend-localredis-pod.yaml
 20 

  1 [root@k8smaster01 study]# kubectl get pods	                #ready为2/2，表示此pod中运行了yaml定义的两个容器
  2 name        ready   status    restarts   age
  3 redis-php   2/2     running   0          7m45s
  4 [root@k8smaster01 study]# kubectl describe pod redis-php	#查看详细信息
  5 

  1 [root@k8snode01 ~]# mkdir -p /etc/kubelet.d
  2 [root@k8snode01 ~]# vi /etc/kubelet.d/static-web.yaml
  3 apiversion: v1
  4 kind: pod
  5 metadata:
  6   name: static-web
  7   label:
  8     name: static-web
  9 spec:
 10   containers:
 11   - name: static-web
 12     image: nginx
 13     ports:
 14     - name: web
 15       containersport: 80
 16 
 17 [root@k8snode01 ~]# vi /etc/systemd/system/kubelet.service
 18 ……
 19   --config=/etc/kubelet.d/ \·				#加入此参数
 20 ……
 21 [root@k8snode01 ~]# systemctl daemon-reload
 22 [root@k8snode01 ~]# systemctl restart kubelet.service	#重启kubelet
 23 [root@k8snode01 ~]# docker ps				#查看创建的pod

  1 [root@k8smaster01 study]# vi pod-volume-applogs.yaml
  2 apiversion: v1
  3 kind: pod
  4 metadata:
  5   name: volume-pod
  6 spec:
  7   containers:
  8   - name: tomcat
  9     image: tomcat
 10     ports:
 11     - containerport: 8080
 12     volumemounts:
 13     - name: app-logs
 14       mountpath: /usr/local/tomcat/logs
 15   - name: logreader
 16     image: busybox
 17     command: ["sh","-c","tail -f /logs/catalina*.log"]
 18     volumemounts:
 19     - name: app-logs
 20       mountpath: /logs
 21   volumes:
 22   - name: app-logs
 23     emptydir: {}

  1 [root@k8smaster01 study]# kubectl create -f pod-volume-applogs.yaml	#创建
  2 [root@k8smaster01 study]# kubectl get pods				#查看
  3 [root@k8smaster01 study]# kubectl logs volume-pod -c busybox	#读取log

  1 [root@k8smaster01 study]# kubectl exec -it volume-pod -c tomcat -- ls /usr/local/tomcat/logs
  2 catalina.2019-06-29.log      localhost_access_log.2019-06-29.txt
  3 host-manager.2019-06-29.log  manager.2019-06-29.log
  4 localhost.2019-06-29.log
  5 [root@k8smaster01 study]# kubectl exec -it volume-pod -c tomcat -- tail /usr/local/tomcat/logs/catalina.2019-06-29.log

  1 [root@k8smaster01 study]# vi cm-appvars.yaml
  2 apiversion: v1
  3 kind: configmap
  4 metadata:
  5   name: cm-appvars
  6 data:
  7   apploglevel: info
  8   appdatadir: /var/data
  9 
 10 [root@k8smaster01 study]# kubectl create -f cm-appvars.yaml
 11 configmap/cm-appvars created
 12 [root@k8smaster01 study]# kubectl get configmaps
 13 name         data   age
 14 cm-appvars   2      8s
 15 [root@k8smaster01 study]# kubectl describe configmaps cm-appvars

  1 [root@k8smaster01 study]# kubectl get configmaps cm-appvars -o yaml

  1 [root@k8smaster01 study]# vi cm-test-pod.yaml
  2 apiversion: v1
  3 kind: pod
  4 metadata:
  5   name: cm-test-pod
  6 spec:
  7   containers:
  8   - name: cm-test
  9     image: busybox
 10     command: ["/bin/sh","-c","env|grep app"]	#容器里执行查看环境变量的命令
 11     env:
 12     - name: apploglevel				#定义容器环境变量名称
 13       valuefrom:
 14         configmapkeyref:			#环境变量的值来自configmap
 15           name: cm-appvars			#指定来自cm-appvars的configmap
 16           key: apploglevel			#key为apploglevel
 17     - name: appdatadir
 18       valuefrom:
 19         configmapkeyref:
 20           name: cm-appvars
 21           key: appdatadir
 22 
 23 [root@k8smaster01 study]# kubectl create -f cm-test-pod.yaml
 24 [root@k8smaster01 study]# kubectl get pods
 25 name          ready   status      restarts   age
 26 cm-test-pod   0/1     completed   2          24s

  1 [root@k8smaster01 study]# vi dapi-test-pod.yaml
  2 apiversion: v1
  3 kind: pod
  4 metadata:
  5   name: dapi-test-pod
  6 spec:
  7   containers:
  8     - name: test-container
  9       image: busybox
 10       command: [ "/bin/sh", "-c", "env" ]
 11       env:
 12         - name: my_pod_name
 13           valuefrom:
 14             fieldref:
 15               fieldpath: metadata.name
 16         - name: my_pod_namespace
 17           valuefrom:
 18             fieldref:
 19               fieldpath: metadata.namespace
 20         - name: my_pod_ip
 21           valuefrom:
 22             fieldref:
 23               fieldpath: status.podip
 24   restartpolicy: never

  1 [root@k8smaster01 study]# kubectl create -f dapi-test-pod.yaml
  2 [root@k8smaster01 study]# kubectl logs dapi-test-pod | grep my_pod
  3 my_pod_namespace=default
  4 my_pod_ip=172.30.240.4
  5 my_pod_name=dapi-test-pod
  6 

  1 [root@k8smaster01 study]# vi dapi-test-pod-container-vars.yaml
  2 apiversion: v1
  3 kind: pod
  4 metadata:
  5   name: dapi-test-pod-container-vars
  6 spec:
  7   containers:
  8     - name: test-container
  9       image: busybox
 10       imagepullpolicy: never
 11       command: [ "/bin/sh", "-c" ]
 12       args:
 13       - while true; do
 14           echo -en '\n';
 15           printenv my_cpu_request my_cpu_limit;
 16           printenv my_mem_request my_mem_limit;
 17           sleep 3600;
 18         done;
 19       resources:
 20         requests:
 21           memory: "32mi"
 22           cpu: "125m"
 23         limits:
 24           memory: "64mi"
 25           cpu: "250m"
 26       env:
 27         - name: my_cpu_request
 28           valuefrom:
 29             resourcefieldref:
 30               containername: test-container
 31               resource: requests.cpu
 32         - name: my_cpu_limit
 33           valuefrom:
 34             resourcefieldref:
 35               containername: test-container
 36               resource: limits.cpu
 37         - name: my_mem_request
 38           valuefrom:
 39             resourcefieldref:
 40               containername: test-container
 41               resource: requests.memory
 42         - name: my_mem_limit
 43           valuefrom:
 44             resourcefieldref:
 45               containername: test-container
 46               resource: limits.memory
 47   restartpolicy: never

  1 [root@k8smaster01 study]# kubectl create -f dapi-test-pod-container-vars.yaml
  2 [root@k8smaster01 study]# kubectl logs dapi-test-pod-container-vars
  3 1
  4 1
  5 33554432
  6 67108864

  1 [root@k8smaster01 study]# vi dapi-test-pod-volume.yaml
  2 apiversion: v1
  3 kind: pod
  4 metadata:
  5   name: dapi-test-pod-volume
  6   labels:
  7     zone: us-est-coast
  8     cluster: test-cluster1
  9     rack: rack-22
 10   annotations:
 11     build: two
 12     builder: john-doe
 13 spec:
 14   containers:
 15     - name: test-container
 16       image: busybox
 17       imagepullpolicy: never
 18       command: [ "/bin/sh", "-c" ]
 19       args:
 20       - while true; do
 21           if [[ -e /etc/labels ]]; then
 22             echo -en '\n\n'; cat /etc/labels; fi;
 23           if [[ -e /etc/annotations ]]; then
 24             echo -en '\n\n'; cat /etc/annotations; fi;
 25           sleep 3600;
 26         done;
 27       volumemounts:
 28         - name: podinfo
 29           mountpath: /etc
 30           readonly: false
 31   volumes:
 32     - name: podinfo
 33       downwardapi:
 34         items:
 35           - path: "labels"
 36             fieldref:
 37               fieldpath: metadata.labels
 38           - path: "annotations"
 39             fieldref:
 40               fieldpath: metadata.annotations

  1 [root@k8smaster01 study]# kubectl create -f dapi-test-pod-volume.yaml
  2 [root@k8smaster01 study]# kubectl logs dapi-test-pod-volume
  3