目录
4.1 DaemonSet+HostNetwork+nodeSelector模式的service
4.2 Deployment+NodePort模式的Service
service的作用体现在两个方面,对集群内部,它不断跟踪pod的变化,更新endpoint中对应pod的对象,提供了ip不断变化的pod的服务发现机制;对集群外部,他类似负载均衡器,可以在集群内外部对pod进行访问。
在Kubernetes中,Pod的IP地址和service的ClusterIP仅可以在集群网络内部使用,对于集群外的应用是不可见的。为了使外部的应用能够访问集群内的服务,Kubernetes目前提供了以下几种方案:
ingress:nginx配置文件
ingress是一个API对象,通过yaml文件来配置,ingress对象的作用是定义请求如何转发到service的规则,可以理解为配置模板。
ingress通过http或https暴露集群内部service,给service提供外部URL、负载均衡、SSL/TLS以及基于域名的反向代理。ingress要依靠 ingress-controller 来具体实现以上功能。
ingress-controller: 当做反向代理或者说是转发器
ingress-controller是具体实现反向代理及负载均衡的程序,对ingress定义的规则进行解析,根据配置的规则来实现请求转发。
ingress-controller并不是k8s自带的组件,实际上ingress-controller只是一个统称,用户可以选择不同的ingress-controller实现,目前,由k8s维护的ingress-controller只有google云的GCE与ingress-nginx两个,其他还有很多第三方维护的ingress-controller,具体可以参考官方文档。但是不管哪一种ingress-controller,实现的机制都大同小异,只是在具体配置上有差异。
一般来说,ingress-controller的形式都是一个pod,里面跑着daemon程序和反向代理程序。daemon负责不断监控集群的变化,根据 ingress对象生成配置并应用新配置到反向代理,比如ingress-nginx就是动态生成nginx配置,动态更新upstream,并在需要的时候reload程序应用新配置。为了方便,后面的例子都以k8s官方维护的ingress-nginx为例。
Ingress-Nginx github 地址:https://github.com/kubernetes/ingress-nginx
Ingress-Nginx 官方网站:https://kubernetes.github.io/ingress-nginx/
总结:ingress-controller才是负责具体转发的组件,通过各种方式将它暴露在集群入口,外部对集群的请求流量会先到 ingress-controller, 而ingress对象是用来告诉ingress-controller该如何转发请求,比如哪些域名、哪些URL要转发到哪些service等等。
(1)ingress-controller通过和 kubernetes APIServer 交互,动态的去感知集群中ingress规则变化,
(2)然后读取它,按照自定义的规则,规则就是写明了哪个域名对应哪个service,生成一段nginx配置,
(3)再写到nginx-ingress-controller的pod里,这个ingress-controller的pod里运行着一个Nginx服务,控制器会把生成的 nginx配置写入 /etc/nginx.conf文件中,
(4)然后reload一下使配置生效。以此达到域名区分配置和动态更新的作用。
- mkdir /opt/ingress
- cd /opt/ingress
-
- 官方下载地址:
- wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/nginx-0.25.0/deploy/static/mandatory.yaml
-
- 上面可能无法下载,可用国内的 gitee
- wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.25.0/deploy/static/mandatory.yaml
- wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.30.0/deploy/static/mandatory.yaml
-
-
- #mandatory.yaml文件中包含了很多资源的创建,包括namespace、ConfigMap、role,ServiceAccount等等所有部署ingress-controller需要的资源。
- vim mandatory.yaml
- ......
- apiVersion: rbac.authorization.k8s.io/v1beta1
- #RBAC相关资源从1.17版本开始改用rbac.authorization.k8s.io/v1,rbac.authorization.k8s.io/v1beta1在1.22版本即将弃用
- 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:
- - "extensions"
- - "networking.k8s.io" # (0.25版本)增加 networking.k8s.io Ingress 资源的 api
- resources:
- - ingresses
- verbs:
- - get
- - list
- - watch
- - apiGroups:
- - ""
- resources:
- - events
- verbs:
- - create
- - patch
- - apiGroups:
- - "extensions"
- - "networking.k8s.io" # (0.25版本)增加 networking.k8s.io/v1 Ingress 资源的 api
- resources:
- - ingresses/status
- verbs:
- - update
ingress 暴露服务的方式
(1)方式一:Deployment+LoadBalancer 模式的 Service
如果要把ingress部署在公有云,那用这种方式比较合适。用Deployment部署ingress-controller,创建一个 type为 LoadBalancer 的 service 关联这组 pod。大部分公有云,都会为 LoadBalancer 的 service 自动创建一个负载均衡器,通常还绑定了公网地址。 只要把域名解析指向该地址,就实现了集群服务的对外暴露
(2)方式二:DaemonSet+HostNetwork+nodeSelector
用DaemonSet结合nodeselector来部署ingress-controller到特定的node上,然后使用HostNetwork直接把该pod与宿主机node的网络打通,直接使用宿主机的80/433端口就能访问服务。这时,ingress-controller所在的node机器就很类似传统架构的边缘节点,比如机房入口的nginx服务器。该方式整个请求链路最简单,性能相对NodePort模式更好。缺点是由于直接利用宿主机节点的网络和端口,一个node只能部署一个ingress-controller pod。 比较适合大并发的生产环境使用。
(3)方式三:Deployment+NodePort模式的Service
同样用deployment模式部署ingress-controller,并创建对应的service,但是type为NodePort。这样,ingress就会暴露在集群节点ip的特定端口上。由于nodeport暴露的端口是随机端口,一般会在前面再搭建一套负载均衡器来转发请求。该方式一般用于宿主机是相对固定的环境ip地址不变的场景。
NodePort方式暴露ingress虽然简单方便,但是NodePort多了一层NAT,在请求量级很大时可能对性能会有一定影响。
- kubectl label node node02 ingress=true
- ##更改node 标签
- kubectl get nodes --show-labels
- vim mandatory.yaml
- ...
- apiVersion: apps/v1
- # 修改 kind
- # kind: Deployment
- 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:
- # 删除Replicas
- # 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:
- # 使用主机网络
- hostNetwork: true
- # 选择节点运行
- nodeSelector:
- ingress: "true"
- serviceAccountName: nginx-ingress-serviceaccount
- ......
- cd /opt/ingress
- tar zxvf ingree.contro.tar.gz
- docker load -i ingree.contro.tar
- #nginx-ingress-controller 已经运行 node02 节点
- kubectl get pod -n ingress-nginx -o wide
- NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
- nginx-ingress-controller-99h72 1/1 Running 0 93s 192.168.10.21 node02
-
- kubectl get cm,daemonset -n ingress-nginx -o wide
- NAME DATA AGE
- configmap/ingress-controller-leader-nginx 0 100s
- configmap/nginx-configuration 0 102s
- configmap/tcp-services 0 102s
- configmap/udp-services 0 102s
-
- NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
- nginx-ingress-controller 1 1 1 1 1 ingress=true 16m
-
- #到 node02 节点查看
- netstat -lntp | grep nginx
- tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 7131/nginx: master
- tcp 0 0 0.0.0.0:8181 0.0.0.0:* LISTEN 7131/nginx: master
- tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 7131/nginx: master
- tcp6 0 0 :::10254 :::* LISTEN 7098/nginx-ingress-
由于配置了 hostnetwork,nginx 已经在 node 主机本地监听 80/443/8181 端口。其中 8181 是 nginx-controller 默认配置的一个 default backend(Ingress 资源没有匹配的 rule 对象时,流量就会被导向这个 default backend)。
这样,只要访问 node 主机有公网 IP,就可以直接映射域名来对外网暴露服务了。如果要 nginx 高可用的话,可以在多个 node上部署,并在前面再搭建一套 LVS+keepalived 做负载均衡。
- #创建一个 deploy 和 svc
- vim service-nginx.yaml
- apiVersion: apps/v1
- kind: Deployment
- metadata:
- name: nginx-app
- spec:
- replicas: 2
- selector:
- matchLabels:
- app: nginx
- template:
- metadata:
- labels:
- app: nginx
- spec:
- containers:
- - name: nginx
- image: nginx
- imagePullPolicy: IfNotPresent
- ports:
- - containerPort: 80
- ---
- apiVersion: v1
- kind: Service
- metadata:
- name: nginx-app-svc
- spec:
- type: ClusterIP
- ports:
- - protocol: TCP
- port: 80
- targetPort: 80
- selector:
- app: nginx
- ##创建 ingress
- #方法一:(extensions/v1beta1 Ingress 在1.22版本即将弃用)
- vim ingress-app.yaml
- apiVersion: extensions/v1beta1
- kind: Ingress
- metadata:
- name: nginx-app-ingress
- spec:
- rules:
- - host: www.kgc.com
- http:
- paths:
- - path: /
- backend:
- serviceName: nginx-app-svc
- servicePort: 80
-
- #方法二:
- vim ingress-app.yaml
- apiVersion: networking.k8s.io/v1
- kind: Ingress
- metadata:
- name: nginx-app-ingress
- spec:
- rules:
- - host: www.kgc.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- service:
- name: nginx-app-svc
- port:
- number: 80
-
-
- kubectl apply -f service-nginx.yaml
- kubectl apply -f ingress-app.yaml
-
- kubectl get pods
- NAME READY STATUS RESTARTS AGE
- nginx-app-7bffc778db-sw2hl 1/1 Running 0 42s
- nginx-app-7bffc778db-xsd5q 1/1 Running 0 42s
-
- kubectl get ingress
- NAME HOSTS ADDRESS PORTS AGE
- nginx-app-ingress www.kgc.com 80 39s
- #本地 host 添加域名解析
- vim /etc/hosts
- 192.168.10.19 master
- 192.168.10.20 node01
- 192.168.10.21 node02
- 192.168.10.21 www.kgc.com
-
- curl www.kgc.com
- kubectl get pod -n ingress-nginx -o wide
- NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
- nginx-ingress-controller-99h72 1/1 Running 0 93s 192.168.10.21 node02
-
- kubectl exec -it nginx-ingress-controller-99h72 -n ingress-nginx /bin/bash
- # more /etc/nginx/nginx.conf
- #可以看到从 start server www.kgc.com 到 end server www.kgc.com 之间包含了此域名用于反向代理的配置
- mkdir /opt/ingress-nodeport
- cd /opt/ingress-nodeport
-
- 官方下载地址:
- wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/nginx-0.30.0/deploy/static/mandatory.yaml
- wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/nginx-0.30.0/deploy/static/provider/baremetal/service-nodeport.yaml
-
- 国内 gitee 资源地址:
- wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.30.0/deploy/static/mandatory.yaml
- wget https://gitee.com/mirrors/ingress-nginx/raw/nginx-0.30.0/deploy/static/provider/baremetal/service-nodeport.yaml
docker load -i ingress-controller-0.30.0.tar
- kubectl apply -f mandatory.yaml
- kubectl apply -f service-nodeport.yaml
- #如果K8S Pod 调度失败,在 kubectl describe pod资源时显示:
- Warning FailedScheduling 18s (x2 over 18s) default-scheduler 0/2 nodes are available: 2 node(s) didn't match node selector
- 解决方案:
- 1. 给需要调度的node加上对应标签
- # 相对上面这个Yaml文件的例子
- kubectl label nodes node_name kubernetes.io/os=linux
- 2. 删除Yaml文件中的nodeSelector,如果对节点没有要求的话,直接删除节点选择器即可
- kubectl get pod,svc -n ingress-nginx
- NAME READY STATUS RESTARTS AGE
- pod/nginx-ingress-controller-7fcf8df75d-x47l8 1/1 Running 0 21m
-
- NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
- service/ingress-nginx NodePort 10.96.67.119
80:32383/TCP,443:32133/TCP 2s
1、创建 deployment、Service、Ingress Yaml 资源
- vim ingress-nginx.yaml
- apiVersion: apps/v1
- kind: Deployment
- metadata:
- name: nginx-app
- spec:
- replicas: 2
- selector:
- matchLabels:
- name: nginx
- template:
- metadata:
- labels:
- name: nginx
- spec:
- containers:
- - name: nginx
- image: nginx
- imagePullPolicy: IfNotPresent
- ports:
- - containerPort: 80
- ---
- apiVersion: v1
- kind: Service
- metadata:
- name: nginx-svc
- spec:
- ports:
- - port: 80
- targetPort: 80
- protocol: TCP
- selector:
- name: nginx
- ---
- apiVersion: networking.k8s.io/v1
- kind: Ingress
- metadata:
- name: nginx-test
- spec:
- rules:
- - host: www.benet.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- service:
- name: nginx-svc
- port:
- number: 80
- kubectl apply -f ingress-nginx.yaml
-
- kubectl get svc,pods -o wide
- NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
- service/kubernetes ClusterIP 10.96.0.1
443/TCP 8h - service/nginx-svc ClusterIP 10.96.212.214
80/TCP 65s name =nginx -
- NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
- pod/nginx-app-65d7b99f6b-l4g65 1/1 Running 0 65s 10.244.1.8 node01
- pod/nginx-app-65d7b99f6b-zcqgp 1/1 Running 0 65s 10.244.2.8 node02
-
-
- kubectl exec -it pod/nginx-app-65d7b99f6b-l4g65 bash
- # cd /usr/share/nginx/html/
- # echo 'this is web1' >> index.html
-
- kubectl exec -it pod/nginx-app-65d7b99f6b-zcqgp bash
- # cd /usr/share/nginx/html/
- # echo 'this is web2' >> index.html
curl 10.96.212.214
- kubectl get svc -n ingress-nginx
- NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
- ingress-nginx NodePort 10.96.67.119
80:32383/TCP,443:32133/TCP 59m - #本地 host 添加域名解析
- vim /etc/hosts
- 192.168.10.19 master
- 192.168.10.20 node01
- 192.168.10.21 node02
- 192.168.80.21 www.kgc.com www.benet.com
- #外部访问
- curl http://www.benet.com:32383
- mkdir /opt/ingress-nodeport/vhost
- cd /opt/ingress-nodeport/vhost
-
- #创建虚拟主机1资源
- vim deployment1.yaml
- apiVersion: apps/v1
- kind: Deployment
- metadata:
- name: deployment1
- spec:
- replicas: 2
- selector:
- matchLabels:
- name: nginx1
- template:
- metadata:
- labels:
- name: nginx1
- spec:
- containers:
- - name: nginx1
- image: soscscs/myapp:v1
- imagePullPolicy: IfNotPresent
- ports:
- - containerPort: 80
- ---
- apiVersion: v1
- kind: Service
- metadata:
- name: svc-1
- spec:
- ports:
- - port: 80
- targetPort: 80
- protocol: TCP
- selector:
- name: nginx1
-
-
- kubectl apply -f deployment1.yaml
-
- #创建虚拟主机2资源
- vim deployment2.yaml
- apiVersion: apps/v1
- kind: Deployment
- metadata:
- name: deployment2
- spec:
- replicas: 2
- selector:
- matchLabels:
- name: nginx2
- template:
- metadata:
- labels:
- name: nginx2
- spec:
- containers:
- - name: nginx2
- image: soscscs/myapp:v2
- imagePullPolicy: IfNotPresent
- ports:
- - containerPort: 80
- ---
- apiVersion: v1
- kind: Service
- metadata:
- name: svc-2
- spec:
- ports:
- - port: 80
- targetPort: 80
- protocol: TCP
- selector:
- name: nginx2
kubectl apply -f deployment2.yaml
- vim ingress-nginx.yaml
- apiVersion: networking.k8s.io/v1
- kind: Ingress
- metadata:
- name: ingress1
- spec:
- rules:
- - host: www1.kgc.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- service:
- name: svc-1
- port:
- number: 80
- ---
- apiVersion: networking.k8s.io/v1
- kind: Ingress
- metadata:
- name: ingress2
- spec:
- rules:
- - host: www2.kgc.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- service:
- name: svc-2
- port:
- number: 80
-
-
- kubectl apply -f ingress-nginx.yaml
-
- kubectl get svc -n ingress-nginx
- NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
- ingress-nginx NodePort 10.96.67.119
80:32383/TCP,443:32133/TCP 176m - curl www1.kgc.com:32383
- Hello MyApp | Version: v1 | ="hostname.html">Pod Name
-
- curl www2.kgc.com:32383
- Hello MyApp | Version: v2 | "hostname.html">Pod Name
-
- mkdir /opt/ingress-nodeport/https
- cd /opt/ingress-nodeport/https
-
- #创建ssl证书
- openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/CN=nginxsvc/O=nginxsvc"
-
- #创建 secret 资源进行存储
- kubectl create secret tls tls-secret --key tls.key --cert tls.crt
-
- kubectl get secret
- NAME TYPE DATA AGE
- tls-secret kubernetes.io/tls 2 2m22s
-
- kubectl describe secret tls-secret
- Name: tls-secret
- Namespace: default
- Labels:
- Annotations:
-
- Type: kubernetes.io/tls
-
- Data
- ====
- tls.crt: 1143 bytes
- tls.key: 1704 bytes
-
-
- #创建 deployment、Service、Ingress Yaml 资源
- vim ingress-https.yaml
- apiVersion: apps/v1
- kind: Deployment
- metadata:
- name: nginx-app
- spec:
- replicas: 2
- selector:
- matchLabels:
- name: nginx
- template:
- metadata:
- labels:
- name: nginx
- spec:
- containers:
- - name: nginx
- image: nginx
- imagePullPolicy: IfNotPresent
- ports:
- - containerPort: 80
- ---
- apiVersion: v1
- kind: Service
- metadata:
- name: nginx-svc
- spec:
- ports:
- - port: 80
- targetPort: 80
- protocol: TCP
- selector:
- name: nginx
- ---
- apiVersion: networking.k8s.io/v1
- kind: Ingress
- metadata:
- name: nginx-https
- spec:
- tls:
- - hosts:
- - www3.kgc.com
- secretName: tls-secret
- rules:
- - host: www3.kgc.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- service:
- name: nginx-svc
- port:
- number: 80
-
-
- kubectl apply -f ingress-https.yaml
-
- kubectl get svc -n ingress-nginx
- NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
- ingress-nginx NodePort 10.96.67.119
80:32383/TCP,443:32133/TCP 3h41m
- #访问测试
- 在宿主机的 C:\Windows\System32\drivers\etc\hosts 文件中添加 192.168.80.10 www3.kgc.com 记录。
- 使用谷歌浏览器访问 https://www3.kgc.com:32133
-
-
- ##Nginx 进行 BasicAuth
- mkdir /opt/ingress-nodeport/basic-auth
- cd /opt/ingress-nodeport/basic-auth
-
- #生成用户密码认证文件,创建 secret 资源进行存储
- yum -y install httpd
- htpasswd -c auth zhangsan #认证文件名必须为 auth
- kubectl create secret generic basic-auth --from-file=auth
-
- #创建 ingress 资源
- vim ingress-auth.yaml
- apiVersion: networking.k8s.io/v1
- kind: Ingress
- metadata:
- name: ingress-auth
- annotations:
- #设置认证类型basic
- nginx.ingress.kubernetes.io/auth-type: basic
- #设置secret资源名称basic-auth
- nginx.ingress.kubernetes.io/auth-secret: basic-auth
- #设置认证窗口提示信息
- nginx.ingress.kubernetes.io/auth-realm: 'Authentication Required - zhangsan'
- spec:
- rules:
- - host: auth.kgc.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- service:
- name: nginx-svc
- port:
- number: 80
- ##具体详细设置方法可参考官网https://kubernetes.github.io/ingress-nginx/examples/auth/basic/
-
- kubectl apply -f ingress-auth.yaml
-
- #访问测试
- kubectl get svc -n ingress-nginx
- NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
- ingress-nginx NodePort 10.96.67.119
80:32383/TCP,443:32133/TCP 8h - echo '192.168.10.19 auth.kgc.com' >> /etc/hosts
- 浏览器访问:http://auth.kgc.com:32383
- #metadata.annotations 配置说明
- ●nginx.ingress.kubernetes.io/rewrite-target: <字符串> #必须重定向流量的目标URI
- ●nginx.ingress.kubernetes.io/ssl-redirect: <布尔值> #指示位置部分是否仅可访问SSL(当Ingress包含证书时,默认为true)
- ●nginx.ingress.kubernetes.io/force-ssl-redirect: <布尔值> #即使Ingress未启用TLS,也强制重定向到HTTPS
- ●nginx.ingress.kubernetes.io/app-root: <字符串> #定义Controller必须重定向的应用程序根,如果它在'/'上下文中
- ●nginx.ingress.kubernetes.io/use-regex: <布尔值> #指示Ingress上定义的路径是否使用正则表达式
- vim ingress-rewrite.yaml
- apiVersion: networking.k8s.io/v1
- kind: Ingress
- metadata:
- name: nginx-rewrite
- annotations:
- nginx.ingress.kubernetes.io/rewrite-target: http://www1.kgc.com:32383
- spec:
- rules:
- - host: re.kgc.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- #由于re.kgc.com只是用于跳转不需要真实站点存在,因此svc资源名称可随意定义
- service:
- name: nginx-svc
- port:
- number: 80
-
-
- kubectl apply -f ingress-rewrite.yaml
-
- echo '192.168.10.21 re.kgc.com' >> /etc/hosts
-
- 浏览器访问:http://re.kgc.com:32383
总结:
ingress是k8s集群的请求入口,可以理解为对多个service的再次抽象
通常说的ingress一般包括ingress资源对象及ingress-controller两部分组成
ingress-controller有多种实现,社区原生的是ingress-nginx,根据具体需求选择
ingress自身的暴露有多种方式,需要根据基础环境及业务类型选择合适的方式