来源: 容器编排系统k8s之Ingress资源 – Linux-1874 – 博客园
前文我们了解了k8s上的service资源的相关话题,回顾请参考:https://www.cnblogs.com/qiuhom-1874/p/14161950.html;今天我们来了解下k8s上的Ingress资源的相关话题;
我们知道在k8s上service是用来解决Pod访问问题,它是通过kube-proxy在每个节点上创建iptables规则或ipvs规则,在用户请求某个pod时,用户的请求会被其service规则所捕获,从而实现访问对应pod;对于service来讲,用户请求直接在传输层就被捕获转发,效率很高效,但这同时也引入了一个新问题;比如我们运行的pod对外客户端访问需要https通信,如果使用service这种4层调度,那就意味着每个pod上我们要配置证书,这很显然不是我们想要做的;那有没有什么办法做到在用户访问pod对应的service时使用https,而对应pod里又不用https协议呢?答案是有的;比如我们可以使用nginx来做https会话卸载器;我们只需要在代理上配置证书即可;又比如我们在k8s上运行了各种各样的pod,这些pod的功能每个都不一样,有点是专门处理用户认证的,有点是专门处理站点主页的,有点专门处理支付的等等,而这些pod对外都是提供一个独有的url,那么这些pod需要怎么才能被集群外部访问到呢?我们知道对于一个站点来讲,如果后端有多个server同时提供一种服务,我们可以把这些同功能的server定义成一个组,然后使用nginx代理将不同功能url的访问代理到不同组上即可;这样一来解决了后端多server被负载访问的问题;那么对于k8s上这种同功能的pod怎么归并成一个组呢?用户访问不同url怎么调度到不同的组上呢?很显然要想实现这些功能,在k8s上应该有一个类似nginx一样的代理存在;这个代理就叫做ingress 控制器;ingress 控制器和k8s上的其他控制不一样,ingress控制器并不能直接运行为kube-controller-manager的一部分,它类似k8s集群上的coredns,需要在集群上单独部署,本质上就是一个pod,我们可以使用k8s上的ds或deploy控制器来创建它;ingress controller pod的作用主要是引入集群外部流量,并实时监控着apiserver上ingress资源的变动,并将其ingress中定义的规则转化为对应ingress控制器对应应用程序的专有配置,然后动态的重载或重启对应守护进程来使其配置文件生效;在k8s上ingress是一种标准资源,它本质上就是我们定义的基于dns名称(host)或url路径把请求转发至指定service资源的规则;简单讲ingress就是我们用来定义代理的配置所创建的资源;ingress控制器就是把对应ingress规则转换为对应ingress控制器中应用程序的专有配置,然后重启或重载对应配置文件使其生效的组件;
ingress和ingress controller pod的关系
提示:如上图所示,ingress就是ingress 控制器pod的代理规则;用户请求某个后端pod所提供的服务时,首先会通过ingress controller pod把流量引入到集群内部,然后ingress controller pod根据ingress定义的规则,把对应ingress规则转化为对应ingress controller pod实现的对应应用的配置(ingress controller 可以由任何具有七层反向代理功能的服务实现,比如nginx,haproxy等等)然后再适配用户请求,把对应请求反代到对应service上;而对于pod的选择上,ingress控制器可以基于对应service中的标签选择器,直接同pod直接通信,无须通过service对象api的再次转发,从而省去了用户请求到kube-proxy实现的代理开销(本质上ingress controller 也是运行为一个pod,和其他pod在同一网段中);
ingress controller部署
在k8s上ingress controller的实现有很多,比如基于nginx的,基于haproxy的等等,这里以nginx为例;
下载ingress-nginx包
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wget https: //github .com /kubernetes/ingress-nginx/archive/nginx-0 .28.0. tar .gz |
解压包,找到对应的部署清单
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[root@master01 ~] # ll total 92144 -rw------- 1 root root 65586688 Dec 8 15:16 flannel-v0.13.1-rc1. tar drwxr-xr-x 2 root root 4096 Dec 21 21:04 manifests -rw-r--r-- 1 root root 28760559 Dec 21 21:02 nginx-0.28.0. tar .gz [root@master01 ~] # tar xf nginx-0.28.0.tar.gz [root@master01 ~] # ls flannel-v0.13.1-rc1. tar ingress-nginx-nginx-0.28.0 manifests nginx-0.28.0. tar .gz [root@master01 ~] # cd ingress-nginx-nginx-0.28.0/ [root@master01 ingress-nginx-nginx-0.28.0] # ls build code-of-conduct.md docs hack labels.yaml mkdocs.yml README.md SECURITY_CONTACTS version Changelog.md CONTRIBUTING.md go.mod images LICENSE OWNERS requirements-docs.txt test cmd deploy go. sum internal Makefile OWNERS_ALIASES rootfs vendor [root@master01 ingress-nginx-nginx-0.28.0] # cd deploy/ [root@master01 deploy] # ls aws cloud-generic grafana prometheus static with-validating-webhook.yaml.tpl baremetal cluster-wide minikube README.md validating-webhook.yaml.tpl [root@master01 deploy] # cd static/ [root@master01 static] # ls configmap.yaml mandatory.yaml namespace.yaml provider rbac.yaml with-rbac.yaml [root@master01 static] # pwd /root/ingress-nginx-nginx-0 .28.0 /deploy/static [root@master01 static] # |
提示:资源配置清单在ingress-nginx-nginx-0.28.0/deploy/static下,名为mandatory.yaml;
资源配置清单内容
apiVersion: v1 kind: Namespace metadata: name: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- kind: ConfigMap apiVersion: v1 metadata: name: nginx-configuration namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- 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 --- 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 --- apiVersion: v1 kind: ServiceAccount metadata: name: nginx-ingress-serviceaccount namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRole metadata: name: nginx-ingress-clusterrole labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx rules: - apiGroups: - "" resources: - configmaps - endpoints - nodes - pods - secrets verbs: - list - watch - apiGroups: - "" resources: - nodes verbs: - get - apiGroups: - "" resources: - services verbs: - get - list - watch - apiGroups: - "" resources: - events verbs: - create - patch - apiGroups: - "extensions" - "networking.k8s.io" resources: - ingresses verbs: - get - list - watch - apiGroups: - "extensions" - "networking.k8s.io" resources: - ingresses/status verbs: - update --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role metadata: name: nginx-ingress-role namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: 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 labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: 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 labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: nginx-ingress-clusterrole subjects: - kind: ServiceAccount name: nginx-ingress-serviceaccount namespace: ingress-nginx --- apiVersion: apps/v1 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: # wait up to five minutes for the drain of connections terminationGracePeriodSeconds: 300 serviceAccountName: nginx-ingress-serviceaccount nodeSelector: kubernetes.io/os: linux containers: - name: nginx-ingress-controller image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.28.0 args: - /nginx-ingress-controller - --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: allowPrivilegeEscalation: true capabilities: drop: - ALL add: - NET_BIND_SERVICE # www-data -> 101 runAsUser: 101 env: - name: POD_NAME valueFrom: fieldRef: fieldPath: metadata.name - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace ports: - name: http containerPort: 80 protocol: TCP - name: https containerPort: 443 protocol: TCP livenessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 10 readinessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP periodSeconds: 10 successThreshold: 1 timeoutSeconds: 10 lifecycle: preStop: exec: command: - /wait-shutdown --- apiVersion: v1 kind: LimitRange metadata: name: ingress-nginx namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx spec: limits: - default: min: memory: 90Mi cpu: 100m type: Container
提示:以上清单主要定义了一个名称ingress-nginx的名称空间,在其名称空间下创建了几个configmap,最重要的是用deployment创建了一个ingress-nginx pod;
这里说一下,对于ingress-nginx控制器,它本质还是运行为一个pod,对于pod来说要想接入外部访问流量到集群内部来,有三种方式,一种是使用NodePort类型的service;第二种是使用ds或deploy控制器,在定义pod模板时使用hostPort把pod端口映射到宿主机方式;第三种是定义pod模板时使用hostNetwork,直接共享宿主机网络名称空间;如下所示
使用专有NodePort service来引入外部流量
提示:这种使用deploy控制管理ingress controller pod,如果在pod模板中没有暴露端口,则需要创建一个service资源来暴露ingress controller pod的端口来引入外部流量到集群内部;
使用ds控制器管理ingress controller pod在pod模板中使用hostPort方式暴露端口
提示:使用ds控制器能够保证每个节点上只运行一个ingress controller,所以我们可以把对应ingress controller pod端端口通过端口映射的方式映射到宿主机上的某一固定端口;
使用ds控制器在pod模板中使用hostNetwork方式共享宿主机网络名称空间
提示:共享宿主机网络名称空间,也必须使用ds控制器来确保对应每个节点上只能运行一个ingress controller pod,这样才能确保每个ingress controller pod能够正常把端口暴露出去,以供集群外部客户端访问;
选择上述其中一种方式暴露ingress controller pod的端口即可;如果选择使用ds控制器来暴露端口,我们就需要修改其对应资源配置清单中的pod模板,如下所示
使用ds控制器来管理ingress controller pod在pod模板中使用hostPort方式暴露端口
apiVersion: v1 kind: Namespace metadata: name: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- kind: ConfigMap apiVersion: v1 metadata: name: nginx-configuration namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- 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 --- 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 --- apiVersion: v1 kind: ServiceAccount metadata: name: nginx-ingress-serviceaccount namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRole metadata: name: nginx-ingress-clusterrole labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx rules: - apiGroups: - "" resources: - configmaps - endpoints - nodes - pods - secrets verbs: - list - watch - apiGroups: - "" resources: - nodes verbs: - get - apiGroups: - "" resources: - services verbs: - get - list - watch - apiGroups: - "" resources: - events verbs: - create - patch - apiGroups: - "extensions" - "networking.k8s.io" resources: - ingresses verbs: - get - list - watch - apiGroups: - "extensions" - "networking.k8s.io" resources: - ingresses/status verbs: - update --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role metadata: name: nginx-ingress-role namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: 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 labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: 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 labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: nginx-ingress-clusterrole subjects: - kind: ServiceAccount name: nginx-ingress-serviceaccount namespace: ingress-nginx --- apiVersion: apps/v1 kind: DaemonSet metadata: name: nginx-ingress-controller namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx spec: 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: # wait up to five minutes for the drain of connections terminationGracePeriodSeconds: 300 serviceAccountName: nginx-ingress-serviceaccount nodeSelector: kubernetes.io/os: linux containers: - name: nginx-ingress-controller image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.28.0 args: - /nginx-ingress-controller - --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: allowPrivilegeEscalation: true capabilities: drop: - ALL add: - NET_BIND_SERVICE # www-data -> 101 runAsUser: 101 env: - name: POD_NAME valueFrom: fieldRef: fieldPath: metadata.name - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace ports: - name: http containerPort: 80 hostPort: 30080 protocol: TCP - name: https containerPort: 443 hostPort: 30443 protocol: TCP livenessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 10 readinessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP periodSeconds: 10 successThreshold: 1 timeoutSeconds: 10 lifecycle: preStop: exec: command: - /wait-shutdown --- apiVersion: v1 kind: LimitRange metadata: name: ingress-nginx namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx spec: limits: - default: min: memory: 90Mi cpu: 100m type: Container
提示:只需把对应控制器类型更改为DaemonSet,在pod模板中spec字段下把replicas去掉;在spec.template.spec.containers.ports字段中加上nodePort字段指定要把容器的端口映射到宿主机上某个端口;如果暴露的端口是非标准端口,在对应k8s集群外部我们还需要部署反代,比如使用nginx,haproxy,lvs;
使用ds控制器管理ingress controller pod在ds控制器资源配置中使用hostNetwork
apiVersion: v1 kind: Namespace metadata: name: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- kind: ConfigMap apiVersion: v1 metadata: name: nginx-configuration namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- 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 --- 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 --- apiVersion: v1 kind: ServiceAccount metadata: name: nginx-ingress-serviceaccount namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: ClusterRole metadata: name: nginx-ingress-clusterrole labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx rules: - apiGroups: - "" resources: - configmaps - endpoints - nodes - pods - secrets verbs: - list - watch - apiGroups: - "" resources: - nodes verbs: - get - apiGroups: - "" resources: - services verbs: - get - list - watch - apiGroups: - "" resources: - events verbs: - create - patch - apiGroups: - "extensions" - "networking.k8s.io" resources: - ingresses verbs: - get - list - watch - apiGroups: - "extensions" - "networking.k8s.io" resources: - ingresses/status verbs: - update --- apiVersion: rbac.authorization.k8s.io/v1beta1 kind: Role metadata: name: nginx-ingress-role namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: 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 labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: 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 labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx roleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: nginx-ingress-clusterrole subjects: - kind: ServiceAccount name: nginx-ingress-serviceaccount namespace: ingress-nginx --- apiVersion: apps/v1 kind: DaemonSet metadata: name: nginx-ingress-controller namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx spec: 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: # wait up to five minutes for the drain of connections terminationGracePeriodSeconds: 300 serviceAccountName: nginx-ingress-serviceaccount nodeSelector: kubernetes.io/os: linux hostNetwork: true containers: - name: nginx-ingress-controller image: quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.28.0 args: - /nginx-ingress-controller - --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: allowPrivilegeEscalation: true capabilities: drop: - ALL add: - NET_BIND_SERVICE # www-data -> 101 runAsUser: 101 env: - name: POD_NAME valueFrom: fieldRef: fieldPath: metadata.name - name: POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace ports: - name: http containerPort: 80 protocol: TCP - name: https containerPort: 443 protocol: TCP livenessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 successThreshold: 1 timeoutSeconds: 10 readinessProbe: failureThreshold: 3 httpGet: path: /healthz port: 10254 scheme: HTTP periodSeconds: 10 successThreshold: 1 timeoutSeconds: 10 lifecycle: preStop: exec: command: - /wait-shutdown --- apiVersion: v1 kind: LimitRange metadata: name: ingress-nginx namespace: ingress-nginx labels: app.kubernetes.io/name: ingress-nginx app.kubernetes.io/part-of: ingress-nginx spec: limits: - default: min: memory: 90Mi cpu: 100m type: Container
提示:把对应控制器类型更改外DaemonSet,在pod模板中spec字段下的replicas字段去掉;在spec.template.spec字段下加上hostNetwork: true即可;以上两种使用ds控制器管理ingress controller pod也可以使用node选择器,来筛选在某个节点上创建ingress controller pod;
使用deploy控制器管理ingress controller pod,就直接应用mandatory.yaml即可
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[root@master01 ~] # kubectl apply -f mandatory.yaml namespace /ingress-nginx created configmap /nginx-configuration created configmap /tcp-services created configmap /udp-services created serviceaccount /nginx-ingress-serviceaccount created Warning: rbac.authorization.k8s.io /v1beta1 ClusterRole is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io /v1 ClusterRole clusterrole.rbac.authorization.k8s.io /nginx-ingress-clusterrole created Warning: rbac.authorization.k8s.io /v1beta1 Role is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io /v1 Role role.rbac.authorization.k8s.io /nginx-ingress-role created Warning: rbac.authorization.k8s.io /v1beta1 RoleBinding is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io /v1 RoleBinding rolebinding.rbac.authorization.k8s.io /nginx-ingress-role-nisa-binding created Warning: rbac.authorization.k8s.io /v1beta1 ClusterRoleBinding is deprecated in v1.17+, unavailable in v1.22+; use rbac.authorization.k8s.io /v1 ClusterRoleBinding clusterrolebinding.rbac.authorization.k8s.io /nginx-ingress-clusterrole-nisa-binding created deployment.apps /nginx-ingress-controller created limitrange /ingress-nginx created [root@master01 ~] # |
查看应用资源清单创建的资源对象
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[root@master01 ~] # kubectl get all -n ingress-nginx NAME READY STATUS RESTARTS AGE pod /nginx-ingress-controller-5466cb8999-4lsjc 1 /1 Running 0 80s NAME READY UP-TO-DATE AVAILABLE AGE deployment.apps /nginx-ingress-controller 1 /1 1 1 80s NAME DESIRED CURRENT READY AGE replicaset.apps /nginx-ingress-controller-5466cb8999 1 1 1 80s [root@master01 ~] # |
提示:可以看到在ingress-nginx名称空间下创建了一个deploy控制器,对应控制器创建了一个nginx-ingress-controller控制器pod;但是此pod现在不能被外部客户端访问到,我们需要创建一个service来引入外部流量到此pod上;
查看pod标签
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[root@master01 ~] # kubectl get pod -n ingress-nginx --show-labels NAME READY STATUS RESTARTS AGE LABELS nginx-ingress-controller-5466cb8999-4lsjc 1 /1 Running 0 4m38s app.kubernetes.io /name =ingress-nginx,app.kubernetes.io /part-of =ingress-nginx,pod-template- hash =5466cb8999 [root@master01 ~] # |
根据上述标签来写一个创建ingress-service资源的配置清单
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[root@master01 ~] # cat ingress-nginx-service.yaml apiVersion: v1 kind: Service metadata: name: ingress-nginx-svc namespace: ingress-nginx spec: type : NodePort ports: - port: 80 name: http nodePort: 30080 - port: 443 name: https nodePort: 30443 selector: app.kubernetes.io /name : ingress-nginx app.kubernetes.io /part-of : ingress-nginx [root@master01 ~] # |
提示:以上配置清单主要把满足对应标签选择器的pod关联起来;并把对应pod的80和443端口分别映射到对应主机上的30080和30443端口;
应用配置清单
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[root@master01 ~] # kubectl apply -f ingress-nginx-service.yaml service /ingress-nginx-svc created [root@master01 ~] # kubectl get svc -n ingress-nginx NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE ingress-nginx-svc NodePort 10.98.4.208 <none> 80:30080 /TCP ,443:30443 /TCP 13s [root@master01 ~] # |
访问集群任意节点ip的30080和30443端口,看看是否访问到对应pod?
提示:30080是能够正常访问的,只是它显示404,是因为我们没有对应的主页;
访问30443端口
提示:30443是一个https端口,所以访问必须用https协议访问,这里提示访问页面有风险是因为浏览器不信任证书引起的,我们可以点击高级,信任证书即可;同样30443端口也是返回404,是因为没有主页的原因;两个端口能够正常访问,说明我们在k8s上部署的ingress-nginx controller就部署好了;
ingress资源的使用
在k8s上创建一个deploy控制器,让其管理2个 ikubernetes/myapp:v1镜像运行的pod,然后再创建一个对应的service
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[root@master01 manifests] # cat myapp-demo.yaml apiVersion: apps /v1 kind: Deployment metadata: name: myapp namespace: default spec: replicas: 2 selector: matchLabels: app: myapp rel: stable template: metadata: namespace: default labels: app: myapp rel: stable spec: containers: - name: myapp image: ikubernetes /myapp :v1 --- apiVersion: v1 kind: Service metadata: name: myapp namespace: default spec: selector: app: myapp rel: stable ports: - name: http port: 80 targetPort: 80 [root@master01 manifests] # |
提示:一个清单中定义多个资源,需要用“—”来分割资源;
应用资源清单
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[root@master01 manifests] # kubectl apply -f myapp-demo.yaml deployment.apps /myapp created service /myapp created [root@master01 manifests] # kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES myapp-6479b786f5-9d4mh 1 /1 Running 0 11s 10.244.2.98 node02.k8s.org <none> <none> myapp-6479b786f5-k252c 1 /1 Running 0 11s 10.244.4.20 node04.k8s.org <none> <none> [root@master01 manifests] # kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443 /TCP 4h52m myapp ClusterIP 10.105.208.218 <none> 80 /TCP 21s [root@master01 manifests] # kubectl describe svc myapp Name: myapp Namespace: default Labels: <none> Annotations: <none> Selector: app=myapp,rel=stable Type: ClusterIP IP Families: <none> IP: 10.105.208.218 IPs: 10.105.208.218 Port: http 80 /TCP TargetPort: 80 /TCP Endpoints: 10.244.2.98:80,10.244.4.20:80 Session Affinity: None Events: <none> [root@master01 manifests] # |
创建ingress资源来反代以上资源
示例:创建ingress资源
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[root@master01 manifests] # cat ingress-myapp.yaml apiVersion: extensions /v1beta1 kind: Ingress metadata: name: ingress-myapp namespace: default annotations: kubernetes.io /ingress .class: "nginx" spec: rules: - host: www.myapp.com http: paths: - path: / backend: serviceName: myapp servicePort: 80 [root@master01 manifests] # |
提示:创建ingress资源apiVersion的值要写成extensions/v1beta1,kind为Ingress;对应metadata中的annotations的配置表示把ingress资源通知给那个类别的ingress controller,如果k8s集群上有多个类别的ingress controller时,这一项特别有用;在spec字段主要内嵌了三个字段,rules字段用来定义反代规则列表,其值为一个对象列表;其中rules字段里主要host和http字段;host用来指定虚拟主机的fqdn名称,如果不写表示匹配任意虚拟主机名称;http是用来定义指向后端的http选择器列表;其值为一个对象,里面只有一个paths字段,用于指定把请求映射到后端的某个路径;其值为一个对象列表;对应paths字段中可以定义path,用来指定映射后端的路径;backend用于指定后端pod的service,其值为一个对象;serviceName用于指定对应pod的service名称;servicePort用于指定后端服务的端口;以上配置表示把www.myapp.com这个虚拟主机的访问全部反代至服务名称为myapp端口为80的pod上;
应用配置清单
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[root@master01 manifests] # kubectl apply -f ingress-myapp.yaml Warning: extensions /v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io /v1 Ingress ingress.extensions /ingress-myapp created [root@master01 manifests] # kubectl get ingress NAME CLASS HOSTS ADDRESS PORTS AGE ingress-myapp <none> www.myapp.com 80 29s [root@master01 manifests] # |
查看ingress资源的详细信息
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[root@master01 manifests] # kubectl describe ingress ingress-myapp Name: ingress-myapp Namespace: default Address: Default backend: default-http-backend:80 (<error: endpoints "default-http-backend" not found>) Rules: Host Path Backends ---- ---- -------- www.myapp.com / myapp:80 (10.244.2.98:80,10.244.4.20:80) Annotations: kubernetes.io /ingress .class: nginx Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal CREATE 81s nginx-ingress-controller Ingress default /ingress-myapp [root@master01 manifests] # |
提示:可以看到对应满足service名称为myapp并且其端口为80的pod有两个;
进入ingress controller pod里,看看对应配置文件是否有www.myapp.com的配置?
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[root@master01 manifests] # kubectl get pods -n ingress-nginx NAME READY STATUS RESTARTS AGE nginx-ingress-controller-5466cb8999-4lsjc 1 /1 Running 0 78m [root@master01 manifests] # kubectl exec -it -n ingress-nginx pod/nginx-ingress-controller-5466cb8999-4lsjc -- /bin/sh /etc/nginx $ cd /etc/nginx/ /etc/nginx $ ls fastcgi.conf koi-utf modsecurity owasp-modsecurity-crs uwsgi_params.default fastcgi.conf.default koi-win modules scgi_params win-utf fastcgi_params lua nginx.conf scgi_params.default fastcgi_params.default mime.types nginx.conf.default template geoip mime.types.default opentracing.json uwsgi_params /etc/nginx $ grep "www.myapp.com" nginx.conf ## start server www.myapp.com server_name www.myapp.com ; ## end server www.myapp.com /etc/nginx $ |
提示:可以看到在对应ingress-nginx 控制器pod中能够搜索到www.myapp.com的配置;说明我们定义的ingress资源已经被ingress-nginx controller 捕获;
用浏览器访问www.myapp.com看看是否能够访问到内容?
提示:使用www.myapp.com访问,需要确保对应域名能够正常解析到k8s集群任意一节点上;可以看到访问www.myapp.com:30080能够访问到对应pod内容;
删除ingress代理规则
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[root@master01 manifests] # kubectl delete -f ingress-myapp.yaml Warning: extensions /v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io /v1 Ingress ingress.extensions "ingress-myapp" deleted [root@master01 manifests] # kubectl get ingress No resources found in default namespace. [root@master01 manifests] # |
示例:配置基于url路径进行流量分发
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[root@master01 manifests] # cat ingress-myapp1.yaml apiVersion: extensions /v1beta1 kind: Ingress metadata: name: ingress-myapp namespace: default annotations: kubernetes.io /ingress .class: "nginx" ingress.kubernetes.io /rewrite-target : / spec: rules: - host: www.myapp.com http: paths: - path: /bbs backend: serviceName: myapp servicePort: 80 - path: /blog backend: serviceName: myapp servicePort: 80 [root@master01 manifests] # |
提示:以上配置表示把www.myapp.com/bbs反代到service名称为myapp并且端口为80的pod上;把www.myapp.com/blog反代到ervice名称为myapp并且端口为80的pod上;我这里是因为k8s上只有这一种应用,生成环境中按照对应的业务逻辑来反代对应url到对应pod上即可;
应用配置清单
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[root@master01 manifests] # kubectl apply -f ingress-myapp1.yaml Warning: extensions /v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io /v1 Ingress ingress.extensions /ingress-myapp created [root@master01 manifests] # kubectl get ingress NAME CLASS HOSTS ADDRESS PORTS AGE ingress-myapp <none> www.myapp.com 80 5s [root@master01 manifests] # kubectl describe ingress ingress-myapp Name: ingress-myapp Namespace: default Address: Default backend: default-http-backend:80 (<error: endpoints "default-http-backend" not found>) Rules: Host Path Backends ---- ---- -------- www.myapp.com /bbs myapp:80 (10.244.2.98:80,10.244.4.20:80) /blog myapp:80 (10.244.2.98:80,10.244.4.20:80) Annotations: ingress.kubernetes.io /rewrite-target : / kubernetes.io /ingress .class: nginx Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal CREATE 30s nginx-ingress-controller Ingress default /ingress-myapp [root@master01 manifests] # |
提示:可以看到对应ingress上就有两个url分别指向后端service名称为myapp端口为80的pod上;
访问对应url,看看是否访问到内容?
提示:这里访问不到内容的原因是对应pod内部并没有对应url的页面;
进入ingress controller pod内部,查看是否有对应配置?
提示:可以看到对应在ingress中定义的配置,都转为对应该ingress controller pod中的配置,说明我们定义基于url分发流量的ingress没有问题;
示例:定义ingress规则基于主机名称的虚拟主机
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[root@master01 manifests] # cat ingress-myapp2.yaml apiVersion: extensions /v1beta1 kind: Ingress metadata: name: ingress-myapp namespace: default annotations: kubernetes.io /ingress .class: "nginx" ingress.kubernetes.io /rewrite-target : / spec: rules: - host: www.myapp.com http: paths: - path: backend: serviceName: myapp servicePort: 80 - host: blog.myapp.com http: paths: - path: backend: serviceName: myapp servicePort: 80 [root@master01 manifests] # |
提示:以上配置表示把www.myapp.com这个虚拟主机名称的访问流量分发至service名称为myapp端口为80的pod上;把blog.myapp.com的流量分发至至service名称为myapp端口为80的pod上;生成环境按照对应的service名称来分发即可;
应用配置清单
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[root@master01 manifests] # kubectl apply -f ingress-myapp2.yaml Warning: extensions /v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io /v1 Ingress ingress.extensions /ingress-myapp created [root@master01 manifests] # kubectl get ingress NAME CLASS HOSTS ADDRESS PORTS AGE ingress-myapp <none> www.myapp.com,blog.myapp.com 80 16s [root@master01 manifests] # kubectl describe ingress ingress-myapp Name: ingress-myapp Namespace: default Address: Default backend: default-http-backend:80 (<error: endpoints "default-http-backend" not found>) Rules: Host Path Backends ---- ---- -------- www.myapp.com myapp:80 (10.244.2.98:80,10.244.4.20:80) blog.myapp.com myapp:80 (10.244.2.98:80,10.244.4.20:80) Annotations: ingress.kubernetes.io /rewrite-target : / kubernetes.io /ingress .class: nginx Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal CREATE 32s nginx-ingress-controller Ingress default /ingress-myapp [root@master01 manifests] # |
验证配置信息
访问对应虚拟主机,看看是否能够访问对应pod?
提示:可以看到两个虚拟主机名称都可以正常访问到,对应也做了调度;
示例:创建tls类型的ingress资源
创建证书
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[root@master01 manifests] # openssl genrsa -out tls.key 2048 Generating RSA private key, 2048 bit long modulus .........................................+++ ........+++ e is 65537 (0x10001) [root@master01 manifests] # openssl req -x509 -key tls.key -out tls.crt -subj /C=CN/ST=SiChuan/L=GuangYuan/O=Test/CN=www.myapp.com -days 3650 [root@master01 manifests] # |
提示:以上两条命令创建了一个名为tls.key的私钥和一个自签名证书,其名为tls.crt;
创建Secret资源
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[root@master01 manifests] # kubectl create secret tls www-myapp-com-ingress-secret --cert=./tls.crt --key=./tls.key secret /www-myapp-com-ingress-secret created [root@master01 manifests] # kubectl get secret NAME TYPE DATA AGE default-token-xvd4c kubernetes.io /service-account-token 3 13d www-myapp-com-ingress-secret kubernetes.io /tls 2 21s [root@master01 manifests] # |
提示:在ingress控制器上配置https主机时,不能直接使用私钥和证书文件,而是需要使用secret资源对象来传递相关数据;
定义tls类型ingress资源清单
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[root@master01 manifests] # cat www-myapp-com-ingress-secret.yaml apiVersion: extensions /v1beta1 kind: Ingress metadata: name: ingress-myapp-tls namespace: default annotations: kubernetes.io /ingress .class: "nginx" spec: tls: - hosts: - www.myapp.com secretName: www-myapp-com-ingress-secret rules: - host: www.myapp.com http: paths: - path: / backend: serviceName: myapp servicePort: 80 [root@master01 manifests] # |
提示:定义tls类型ingress资源清单,需要在spec字段下用tls字段来指定对应主机名称,以及secret资源对象的名称;
应用资源清单
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[root@master01 manifests] # kubectl apply -f www-myapp-com-ingress-secret.yaml Warning: extensions /v1beta1 Ingress is deprecated in v1.14+, unavailable in v1.22+; use networking.k8s.io /v1 Ingress ingress.extensions /ingress-myapp-tls created [root@master01 manifests] # kubectl get ingress NAME CLASS HOSTS ADDRESS PORTS AGE ingress-myapp <none> www.myapp.com,blog.myapp.com 80 31m ingress-myapp-tls <none> www.myapp.com 80, 443 8s [root@master01 manifests] # kubectl describe ingress ingress-myapp-tls Name: ingress-myapp-tls Namespace: default Address: Default backend: default-http-backend:80 (<error: endpoints "default-http-backend" not found>) TLS: www-myapp-com-ingress-secret terminates www.myapp.com Rules: Host Path Backends ---- ---- -------- www.myapp.com / myapp:80 (10.244.2.98:80,10.244.4.20:80) Annotations: kubernetes.io /ingress .class: nginx Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal CREATE 26s nginx-ingress-controller Ingress default /ingress-myapp-tls [root@master01 manifests] # |
验证:访问对应虚拟主机名称,看看对应的https端口是否能够正常访问到内容?
提示:可以看到使用https协议访问对应的30443端口能够正常访问到对应后端pod提供的内容;