kubernetes之ingress及ingress controller
什么是ingress
Ingress是授权入站连接到达集群服务的规则集合。
- 从外部流量调度到nodeprot上的service
- 从service调度到ingress-controller
- ingress-controller根据ingress中的定义（虚拟主机或者后端的url）
- 根据虚拟主机名调度到后端的一组pod中
Ingress资源定义
kubectl explain ingress.spec
- rules 定义成虚拟主机调度还是url调度
- backend 知道后端主机
部署ingress
以下文件是kubenetes的官方提供
创建namespace
apiVersion: v1
kind: Namespace
metadata:
name: ingress-nginx
创建role
--- apiVersion: v1 kind: ServiceAccount metadata: name: nginx-ingress-serviceaccount namespace: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRole metadata: name: nginx-ingress-clusterrole rules: - apiGroups: - "" resources: - configmaps - endpoints - nodes - pods - secrets verbs: - list - watch - apiGroups: - "" resources: - nodes verbs: - get - apiGroups: - "" resources: - services verbs: - get - list - watch - apiGroups: - "extensions" resources: - ingresses verbs: - get - list - watch - apiGroups: - "" resources: - events verbs: - create - patch - apiGroups: - "extensions" resources: - ingresses/status verbs: - update --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role metadata: name: nginx-ingress-role namespace: ingress-nginx rules: - apiGroups: - "" resources: - configmaps - pods - secrets - namespaces verbs: - get - apiGroups: - "" resources: - configmaps resourceNames: # Defaults to "<election-id>-<ingress-class>" # Here: "<ingress-controller-leader>-<nginx>" # This has to be adapted if you change either parameter # when launching the nginx-ingress-controller. - "ingress-controller-leader-nginx" verbs: - get - update - apiGroups: - "" resources: - configmaps verbs: - create - apiGroups: - "" resources: - endpoints verbs: - get --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: RoleBinding metadata: name: nginx-ingress-role-nisa-binding namespace: ingress-nginx roleRef: apiGroup: rbac.authorization.k8s.io kind: Role name: nginx-ingress-role subjects: - kind: ServiceAccount name: nginx-ingress-serviceaccount namespace: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRoleBinding metadata: name: nginx-ingress-clusterrole-nisa-binding roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: nginx-ingress-clusterrole subjects: - kind: ServiceAccount name: nginx-ingress-serviceaccount namespace: ingress-nginx
创建confmap
--- kind: ConfigMap apiVersion: v1 metadata: name: nginx-configuration namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx
创建ingress服务
--- apiVersion: extensions/v1beta1 kind: Deployment metadata: name: nginx-ingress-controller namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx spec: replicas: 1 selector: matchLabels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx template: metadata: labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx annotations: prometheus.io/port: '10254' prometheus.io/scrape: 'true' spec: serviceAccountName: nginx-ingress-serviceaccount containers: - name: nginx-ingress-controller image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.19.0 args: - /nginx-ingress-controller - --default-backend-service=$(POD_NAMESPACE)/default-http-backend - --configmap=$(POD_NAMESPACE)/nginx-configuration - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services - --udp-services-configmap=$(POD_NAMESPACE)/udp-services - --publish-service=$(POD_NAMESPACE)/ingress-nginx - --annotations-prefix=nginx.ingress.kubernetes.io securityContext: capabilities: drop: - ALL add: - NET_BIND_SERVICE # www-data -> 33 runAsUser: 33 env: - name: POD_NAME valueFrom: fieldRef: fieldPath: metadata.name - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace ports: - name: http containerPort: 80 - name: https containerPort: 443 livenessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1 readinessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP periodSeconds: 10 successThreshold: 1 timeoutSeconds: 1
创建TCP服务的confmap
--- kind: ConfigMap apiVersion: v1 metadata: name: tcp-services namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx
创建UDP服务的confmap
--- kind: ConfigMap apiVersion: v1 metadata: name: udp-services namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx
创建backend
--- apiVersion: extensions/v1beta1 kind: Deployment metadata: name: default-http-backend labels: app.kubernetes.io/name: default-http-backend app.kubernetes.io/part-of: ingress-nginx namespace: ingress-nginx spec: replicas: 1 selector: matchLabels: app.kubernetes.io/name: default-http-backend app.kubernetes.io/part-of: ingress-nginx template: metadata: labels: app.kubernetes.io/name: default-http-backend app.kubernetes.io/part-of: ingress-nginx spec: terminationGracePeriodSeconds: 60 containers: - name: default-http-backend # Any image is permissible as long as: # 1. It serves a 404 page at / # 2. It serves 200 on a /healthz endpoint image: gcr.io/google_containers/defaultbackend:1.4 livenessProbe: httpGet: path: /healthz port: 8080 scheme: HTTP initialDelaySeconds: 30 timeoutSeconds: 5 ports: - containerPort: 8080 resources: limits: cpu: 10m memory: 20Mi requests: cpu: 10m memory: 20Mi --- apiVersion: v1 kind: Service metadata: name: default-http-backend namespace: ingress-nginx labels: app.kubernetes.io/name: default-http-backend app.kubernetes.io/part-of: ingress-nginx spec: ports: - port: 80 targetPort: 8080 selector: app.kubernetes.io/name: default-http-backend app.kubernetes.io/part-of: ingress-nginx
部署一个ingress-controller的service nodePort
如果需要集群外部访问，就需要部署一个NodePort的service 用来提供外部访问
apiVersion: v1 kind: Service metadata: name: ingress-nginx namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx spec: type: NodePort ports: - name: http port: 80 targetPort: 80 protocol: TCP nodePort: 30080 - name: https port: 443 targetPort: 443 protocol: TCP nodePort: 30443 selector: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx
尝试访问
部署一个应用通过ingress访问
部署一个myapp的测试应用
apiVersion: v1 kind: Service metadata: name: myapp namespace: default spec: selector: app: myapp release: dev ports: - name: http targetPort: 80 port: 80 --- apiVersion: apps/v1 kind: Deployment metadata: name: myapp-deploy namespace: default spec: replicas: 3 selector: matchLabels: app: myapp release: dev template: metadata: labels: app: myapp release: dev spec: containers: - name: myapp-containers image: ikubernetes/myapp:v2 ports: - name: http containerPort: 80
部署myapp的ingress
apiVersion: extensions/v1beta1 kind: Ingress metadata: name: ingress-myapp namespace: default annotations: kubernetes.io/ingress.class: "nginx" spec: rules: - host: myapp.jaxzhai.com http: paths: - backend: serviceName: myapp servicePort: 80
查看结果
$ kubectl get ing NAME HOSTS ADDRESS PORTS AGE ingress-myapp myapp.jaxzhai.com 80 2m $ kubectl describe ing ingress-myapp Name: ingress-myapp Namespace: default Address: Default backend: default-http-backend:80 (<none>) Rules: Host Path Backends ---- ---- -------- myapp.jaxzhai.com myapp:80 (<none>) Annotations: kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{"kubernetes.io/ingress.class":"nginx"},"name":"ingress-myapp","namespace":"default"},"spec":{"rules":[{"host":"myapp.jaxzhai.com","http":{"paths":[{"backend":{"serviceName":"myapp","servicePort":80}}]}}]}} kubernetes.io/ingress.class: nginx Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal CREATE 2m nginx-ingress-controller Ingress default/ingress-myapp
部署完成后，生成的规则会自动注入到ingress-controller中，意思会生成nginx配置文件，验证：
$ kubectl exec -it -n ingress-nginx nginx-ingress-controller-6bd7c597cb-8qm9x -- /bin/sh $ cat nginx.conf ......... ## start server myapp.jaxzhai.com server { server_name myapp.jaxzhai.com ; listen 80; listen [::]:80; set $proxy_upstream_name "-"; location / { set $namespace "default"; set $ingress_name "ingress-myapp"; set $service_name "myapp"; set $service_port "80"; set $location_path "/"; rewrite_by_lua_block { balancer.rewrite() } log_by_lua_block { balancer.log() monitor.call() } port_in_redirect off; set $proxy_upstream_name "default-myapp-80"; .......
访问应用
