kubernetes（namespace、pod、deployment、service、ingress）

NameSpace

NameSpace名称空间
用来隔离资源，但是不隔离网络
使用命令行：

kubectl create ns hello #创建
kubectl delete ns hello #删除
kubectl get ns  #查看

使用配置文件：

vi hello.yaml

apiVersion: v1
kind: Namespace
metadata:name: hello

kubectl apply -f hello.yaml
kubectl delete -f hello.yaml

Pod

Pod是容器的集合，是kubernetes中应用的最小单位。
在同一个pod中的容器共享网络空间、共享存储

使用 kubectl get pod 可以查看某个pod里面有几个容器以及几个容器正常运行。

kubectl run mynginx --image=nginx #创建
kubectl delete pod mynginx #删除
kubectl get pod # 查看default名称空间的pod（kubectl get pod -n default）
kubectl describe pod mynginx #描述信息
kubectl logs mynginx #查看pod的运行日志
kubectl get pod -owide #查看pod的详细信息，如ip
curl ip #访问kubectl exec -it mynginx -- /bin/bash #进入nginx容器

使用配置文件：
版本一般固定，kind种类为：pod，结尾containers中可以添加多个容器，

apiVersion: v1
kind: Pod
metadata:labels:run: mynginxname: mynginx
#  namespace: default
spec:containers:- image: nginxname: mynginx  

使用dashboard创建：

注意创建时指定名称空间：

apiVersion: v1
kind: Pod
metadata:labels:run: myappname: myapp
spec:containers:- image: nginxname: nginx- image: tomcat:8.5.68name: tomcat

验证同一个pod共享网络空间：

pod内含有多个应用不能占用相同端口，否则会一直重试。

Deployment

部署，使pod拥有自愈、多副本、扩缩容能力。实现了高可用。

自愈

当一台机器的某个服务挂掉后，迅速再另起一个相同的服务。

# 清除所有Pod，比较下面两个命令有何不同效果？
kubectl run mynginx --image=nginxkubectl create deployment mytomcat --image=tomcat:8.5.68
# 自愈能力

第一个删除pod就真没有了，第二个删除pod会新起一个相同的

多副本

创建多个副本，一个

kubectl create deployment my-dep --image=nginx --replicas=3

apiVersion: apps/v1
kind: Deployment
metadata:labels:app: my-depname: my-dep
spec:replicas: 3selector:matchLabels:app: my-deptemplate:metadata:labels:app: my-depspec:containers:- image: nginxname: nginx

扩缩容

一、
将刚创建的deployment（部署）中的pod调整为X台，若X小于当前数量为缩容，大于当前数量为扩容。

kubectl scale --replicas=5 deployment/my-dep

二、或者去配置文件中修改replicas的数量：

kubectl edit deployment my-dep

三、使用可视化dashbroad

滚动更新（灰度更新）

升级deployment中pod的版本，在升级的同时还会有流量打入。这里采用的是先成功running一个pod之后才把对应低版本的pod删除。

kubectl set image deployment/my-dep nginx:nginx:1.16.1 --record

版本回退

查看历史版本信息

kubectl rollout history deployment/my-dep

查看某个版本的具体信息

kubectl rollout history deployment/my-dep --revision=2

回滚至上一次

kubectl rollout undo deployment/my-dep

回滚到指定版本

kubectl rollout undo deployment/my-dep --to-revision=1

小结

Deployment：无状态应用部署，入微服务，提供多副本功能。
StatefulSet：有状态应用部署，如redis，提供稳定的数据存储、网络等功能。
DaemonSet：守护型应用部署，如日志收集组件，每个应用独立一份。
Job / CronJob：定时任务部署，如垃圾回收组件，指定实践运行一次。

Service

ingress

相当于整个k8s网关入口（nginx）

vi ingress.yaml
# 编辑
kubectl apply -f ingress.yaml

ingress.yaml中内容：

apiVersion: v1
kind: Namespace
metadata:name: ingress-nginxlabels:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginx---
# Source: ingress-nginx/templates/controller-serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginxnamespace: ingress-nginx
automountServiceAccountToken: true
---
# Source: ingress-nginx/templates/controller-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controllernamespace: ingress-nginx
data:
---
# Source: ingress-nginx/templates/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmname: ingress-nginx
rules:- apiGroups:- ''resources:- configmaps- endpoints- nodes- pods- secretsverbs:- list- watch- apiGroups:- ''resources:- nodesverbs:- get- apiGroups:- ''resources:- servicesverbs:- get- list- watch- apiGroups:- extensions- networking.k8s.io   # k8s 1.14+resources:- ingressesverbs:- get- list- watch- apiGroups:- ''resources:- eventsverbs:- create- patch- apiGroups:- extensions- networking.k8s.io   # k8s 1.14+resources:- ingresses/statusverbs:- update- apiGroups:- networking.k8s.io   # k8s 1.14+resources:- ingressclassesverbs:- get- list- watch
---
# Source: ingress-nginx/templates/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmname: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginx
subjects:- kind: ServiceAccountname: ingress-nginxnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginxnamespace: ingress-nginx
rules:- apiGroups:- ''resources:- namespacesverbs:- get- apiGroups:- ''resources:- configmaps- pods- secrets- endpointsverbs:- get- list- watch- apiGroups:- ''resources:- servicesverbs:- get- list- watch- apiGroups:- extensions- networking.k8s.io   # k8s 1.14+resources:- ingressesverbs:- get- list- watch- apiGroups:- extensions- networking.k8s.io   # k8s 1.14+resources:- ingresses/statusverbs:- update- apiGroups:- networking.k8s.io   # k8s 1.14+resources:- ingressclassesverbs:- get- list- watch- apiGroups:- ''resources:- configmapsresourceNames:- ingress-controller-leader-nginxverbs:- get- update- apiGroups:- ''resources:- configmapsverbs:- create- apiGroups:- ''resources:- eventsverbs:- create- patch
---
# Source: ingress-nginx/templates/controller-rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginxnamespace: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginx
subjects:- kind: ServiceAccountname: ingress-nginxnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/controller-service-webhook.yaml
apiVersion: v1
kind: Service
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controller-admissionnamespace: ingress-nginx
spec:type: ClusterIPports:- name: https-webhookport: 443targetPort: webhookselector:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-service.yaml
apiVersion: v1
kind: Service
metadata:annotations:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controllernamespace: ingress-nginx
spec:type: NodePortports:- name: httpport: 80protocol: TCPtargetPort: http- name: httpsport: 443protocol: TCPtargetPort: httpsselector:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controller
---
# Source: ingress-nginx/templates/controller-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: controllername: ingress-nginx-controllernamespace: ingress-nginx
spec:selector:matchLabels:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controllerrevisionHistoryLimit: 10minReadySeconds: 0template:metadata:labels:app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/component: controllerspec:dnsPolicy: ClusterFirstcontainers:- name: controllerimage: registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/ingress-nginx-controller:v0.46.0imagePullPolicy: IfNotPresentlifecycle:preStop:exec:command:- /wait-shutdownargs:- /nginx-ingress-controller- --election-id=ingress-controller-leader- --ingress-class=nginx- --configmap=$(POD_NAMESPACE)/ingress-nginx-controller- --validating-webhook=:8443- --validating-webhook-certificate=/usr/local/certificates/cert- --validating-webhook-key=/usr/local/certificates/keysecurityContext:capabilities:drop:- ALLadd:- NET_BIND_SERVICErunAsUser: 101allowPrivilegeEscalation: trueenv:- name: POD_NAMEvalueFrom:fieldRef:fieldPath: metadata.name- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespace- name: LD_PRELOADvalue: /usr/local/lib/libmimalloc.solivenessProbe:failureThreshold: 5httpGet:path: /healthzport: 10254scheme: HTTPinitialDelaySeconds: 10periodSeconds: 10successThreshold: 1timeoutSeconds: 1readinessProbe:failureThreshold: 3httpGet:path: /healthzport: 10254scheme: HTTPinitialDelaySeconds: 10periodSeconds: 10successThreshold: 1timeoutSeconds: 1ports:- name: httpcontainerPort: 80protocol: TCP- name: httpscontainerPort: 443protocol: TCP- name: webhookcontainerPort: 8443protocol: TCPvolumeMounts:- name: webhook-certmountPath: /usr/local/certificates/readOnly: trueresources:requests:cpu: 100mmemory: 90MinodeSelector:kubernetes.io/os: linuxserviceAccountName: ingress-nginxterminationGracePeriodSeconds: 300volumes:- name: webhook-certsecret:secretName: ingress-nginx-admission
---
# Source: ingress-nginx/templates/admission-webhooks/validating-webhook.yaml
# before changing this value, check the required kubernetes version
# https://kubernetes.io/docs/reference/access-authn-authz/extensible-admission-controllers/#prerequisites
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:labels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhookname: ingress-nginx-admission
webhooks:- name: validate.nginx.ingress.kubernetes.iomatchPolicy: Equivalentrules:- apiGroups:- networking.k8s.ioapiVersions:- v1beta1operations:- CREATE- UPDATEresources:- ingressesfailurePolicy: FailsideEffects: NoneadmissionReviewVersions:- v1- v1beta1clientConfig:service:namespace: ingress-nginxname: ingress-nginx-controller-admissionpath: /networking/v1beta1/ingresses
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrole.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhook
rules:- apiGroups:- admissionregistration.k8s.ioresources:- validatingwebhookconfigurationsverbs:- get- update
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/clusterrolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhook
roleRef:apiGroup: rbac.authorization.k8s.iokind: ClusterRolename: ingress-nginx-admission
subjects:- kind: ServiceAccountname: ingress-nginx-admissionnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/role.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
rules:- apiGroups:- ''resources:- secretsverbs:- get- create
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/rolebinding.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:name: ingress-nginx-admissionannotations:helm.sh/hook: pre-install,pre-upgrade,post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
roleRef:apiGroup: rbac.authorization.k8s.iokind: Rolename: ingress-nginx-admission
subjects:- kind: ServiceAccountname: ingress-nginx-admissionnamespace: ingress-nginx
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-createSecret.yaml
apiVersion: batch/v1
kind: Job
metadata:name: ingress-nginx-admission-createannotations:helm.sh/hook: pre-install,pre-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
spec:template:metadata:name: ingress-nginx-admission-createlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhookspec:containers:- name: createimage: docker.io/jettech/kube-webhook-certgen:v1.5.1imagePullPolicy: IfNotPresentargs:- create- --host=ingress-nginx-controller-admission,ingress-nginx-controller-admission.$(POD_NAMESPACE).svc- --namespace=$(POD_NAMESPACE)- --secret-name=ingress-nginx-admissionenv:- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespacerestartPolicy: OnFailureserviceAccountName: ingress-nginx-admissionsecurityContext:runAsNonRoot: truerunAsUser: 2000
---
# Source: ingress-nginx/templates/admission-webhooks/job-patch/job-patchWebhook.yaml
apiVersion: batch/v1
kind: Job
metadata:name: ingress-nginx-admission-patchannotations:helm.sh/hook: post-install,post-upgradehelm.sh/hook-delete-policy: before-hook-creation,hook-succeededlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhooknamespace: ingress-nginx
spec:template:metadata:name: ingress-nginx-admission-patchlabels:helm.sh/chart: ingress-nginx-3.33.0app.kubernetes.io/name: ingress-nginxapp.kubernetes.io/instance: ingress-nginxapp.kubernetes.io/version: 0.47.0app.kubernetes.io/managed-by: Helmapp.kubernetes.io/component: admission-webhookspec:containers:- name: patchimage: docker.io/jettech/kube-webhook-certgen:v1.5.1imagePullPolicy: IfNotPresentargs:- patch- --webhook-name=ingress-nginx-admission- --namespace=$(POD_NAMESPACE)- --patch-mutating=false- --secret-name=ingress-nginx-admission- --patch-failure-policy=Failenv:- name: POD_NAMESPACEvalueFrom:fieldRef:fieldPath: metadata.namespacerestartPolicy: OnFailureserviceAccountName: ingress-nginx-admissionsecurityContext:runAsNonRoot: truerunAsUser: 2000