Service 类型
- ClusterIP 只在集群内部访问,无法跨越集群边界
- NodePort 提供集群外部流量进入到集群内部,是在clusterIP前提之上增强的
- LoadBalancer 集群部署在公有云或私有云之上,提供给公有云或私有云的负载均衡中间使用
- ExternelName 把集群外部的服务映射给集群内部使用, 是一个FQDN的名称,一个CNAME名称,这个CNAM指向公网的FQDN
No ClusterIP 成为 Headless Sercie
ServiceName -> PodIP
Service 是一个四层调度器
也就是说,当请求为HTTPS请求的时候,则无法卸载证书。
namespace 名称空间
;
创建 namespace
如下:
[root@master manifests]# kubectl create namespace dev
namespace/dev created
[root@master manifests]# kubectl get ns
NAME STATUS AGE
default Active 20d
dev Active 4s # 新创建的namespace
kube-node-lease Active 20d
kube-public Active 20d
kube-system Active 20d
删除 namespace
如下:
[root@master manifests]# kubectl delete ns/dev
namespace "dev" deleted
[root@master manifests]# kubectl get ns
NAME STATUS AGE
default Active 20d
kube-node-lease Active 20d
kube-public Active 20d
kube-system Active 20d
Ingress Controller
举例
当kubernetes集群有上千甚至跟多个节点的时候,此时需要特有的web七层代理
如在集群其中的四个节点上打上污点,这四个节点上只运行web七层代理所对应的Pod
由此Pod来代理集群内部的Service,Service再把流量转发给集群内部对应的Pod。
这就叫做 Ingress Controller
Ingress Controller
是基于 DaemonSet
控制器来实现。
DaemonSet
是实现保证集群内部每个节点上都运行一个指定的Pod。
Kubernetes 中三种常用七层代理:
- Nginx # 常规代理
- Traefik # 微服务前段负载均衡
- Envoy # 微服务代理负载均衡,使用的多
Ingress
Ingress
和 Ingress Controller
是两回事。
Ingress 原理
Ingress 启动一个独立的Pod来运行七层代理,可以是
Nginx
、Traefik
或者是Envoy
,此时ingress Pod
会直接代理 后端运行服务的Pod
,为了能监听后端Pod
的变化,需要一个 无头ServiceHeadless Sercie
通过标签选择器来选择后端指定的Pod,并收集到后端Pod
对应的IP
,而此Service
不会被使用,它主要是用于被Ingress Pod
来监听后端Pod
的变化,而一旦后端Pod
产生变化,无头Service 会知道,此时被Ingress Pod
发现后,会自动根据变化来更改配置文件,并重载。
如果此时使用的是
Nginx
类型的Ingress Pod
,则每次变化后修改配置文件后都会自动重新 reload。
但如果使用Traefik
或者是Envoy
天生就是为微服务开发的,更友好的支持。
Ingress-nginx 进行测试
可以在 GitHub 上找到Ingress-nginx
本次使用的是相对简单部署 ingress-nginx 的配置清单。
本文创建的基本流程:创建前端service 创建后端service和pod,创建ingress。
ingress-nginx 单独的详情页面
因为是直接在物理机上直接安装的kubernetes集群,所以需要两个配置清单。
[root@master ingress]# kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/mandatory.yaml
namespace/ingress-nginx created
configmap/nginx-configuration created
configmap/tcp-services created
configmap/udp-services created
serviceaccount/nginx-ingress-serviceaccount created
clusterrole.rbac.authorization.k8s.io/nginx-ingress-clusterrole created
role.rbac.authorization.k8s.io/nginx-ingress-role created
rolebinding.rbac.authorization.k8s.io/nginx-ingress-role-nisa-binding created
clusterrolebinding.rbac.authorization.k8s.io/nginx-ingress-clusterrole-nisa-binding created
deployment.apps/nginx-ingress-controller created
还需要一个Ingress-name名称空间中创建的NodePort Service,以便引入集群外流量
需要根据实际情况修改一下:
[root@master ingress]# wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/provider/baremetal/service-nodeport.yaml
[root@master ingress]# cat service-nodeport.yaml
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 # 手动指定node对外的http端口
- name: https
port: 443
targetPort: 443
protocol: TCP
nodePort: 30443 # 手动指定node对外的https端口
selector:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/part-of: ingress-nginx
[root@master ingress]#kubectl apply -f service-nodeport.yaml
service/ingress-nginx created
查看创建的ingress-nginx
Pod
[root@master ingress]# kubectl get pods -n ingress-nginx -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-ingress-controller-7995bd9c47-b4fzh 1/1 Running 0 34s 10.244.1.27 node03.kubernetes <none> <none>
[root@master ingress]# kubectl get svc -n ingress-nginx # 这里是第二次执行在Ingress-name名称空间中创建的NodePort Service,以便引入集群外流量
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-nginx NodePort 10.111.201.108 <none> 80:30080/TCP,443:30443/TCP 44s
创建对应的后端Pod和Service
查看创建的ingress-myapp
[root@master ingress]# cat myapp-deploy.yaml
apiVersion: v1
kind: Service
metadata:
name: myapp # Service 名称
namespace: default
spec:
selector:
app: myapp
release: canary
ports:
- name: http
targetPort: 80 # 指定容器端口
port: 80 # Service 自己开房的端口
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deploy
namespace: default
spec:
replicas: 3
selector:
matchLabels:
app: myapp
release: canary
template:
metadata:
labels:
app: myapp
release: canary
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v2
ports:
- name: http
containerPort: 80
[root@master ingress]# kubectl apply -f myapp-deplay.yaml
service/myapp created
deployment.apps/myapp-deploy unchanged
查看
[root@master ingress]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-deploy-55b78d8548-b4c2c 1/1 Running 0 42h
myapp-deploy-55b78d8548-gpdw8 1/1 Running 0 42h
myapp-deploy-55b78d8548-hr6vx 1/1 Running 0 42h
[root@master ingress]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 22d
myapp ClusterIP 10.111.44.7 <none> 80/TCP 6s
创建 Ingress
[root@master ingress]# cat ingress-myapp.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: ingress-myapp
namespace: default
annotations:
kubernetes.io/ingress.class: "nginx" # 自动生成 nginx 相关的匹配和修改规则
spec:
rules:
- host: myapp.beijingfc.com # 使用 host 主机模式来访问
http:
paths:
- path:
backend:
serviceName: myapp # 这里指定刚刚创建的后端Pod对应的Service名称
servicePort: 80
[root@master ingress]# kubectl apply -f ingress-myapp.yaml
ingress.extensions/ingress-myapp created
[root@master ingress]# kubectl get ing
NAME HOSTS ADDRESS PORTS AGE
ingress-myapp myapp.beijingfc.com 80 6s
查看 Ingress-controller 对应的Pod配置信息
上面一系列都配置完成之后,此时在看查看 Ingress-controller 的Pod中nginx的配置信息包含如下:
[root@master ingress]# kubectl exec -n ingress-nginx -it nginx-ingress-controller-7995bd9c47-b4fzh -- /bin/sh
$ cat nginx.conf
server {
server_name myapp.beijingfc.com ;
listen 80;
set $proxy_upstream_name "-";
set $pass_access_scheme $scheme;
set $pass_server_port $server_port;
set $best_http_host $http_host;
set $pass_port $pass_server_port;
location / {
set $namespace "default";
set $ingress_name "ingress-myapp";
set $service_name "myapp";
set $service_port "80";
set $location_path "/";
... ...
... ...
访问测试
此时在集群外部访问测试:
注意,临时测试,上面使用的host模式来访问,所以在测试的集群外部机器上手动添加hosts记录
[root@xinguan-test-node1 ~]# grep myapp /etc/hosts
10.0.20.20 myapp.beijingfc.com
[root@xinguan-test-node1 ~]# curl myapp.beijingfc.com:30080
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
[root@xinguan-test-node1 ~]# curl myapp.beijingfc.com:30080/hostname.html
myapp-deploy-55b78d8548-hr6vx
模拟测试 Ingress 后端 Tomcat 访问
还是基于上面的配置,一切都不动,增加tomcat后端Pod和Service 以及 Ingress
创建 tomcat 的 Pod 和Service
[root@master ingress]# cat tomcat-deploy.yaml
apiVersion: v1
kind: Service
metadata:
name: tomcat
namespace: default
spec:
selector:
app: tomcat
release: canary
ports:
- name: http
targetPort: 8080
port: 8080
- name: ajp
targetPort: 8009
port: 8009
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: tomcat-depoly
namespace: default
spec:
replicas: 3
selector:
matchLabels:
app: tomcat
release: canary
template:
metadata:
labels:
app: tomcat
release: canary
spec:
containers:
- name: tomcat
image: tomcat:8.5.32-jre8-alpine
ports:
- name: http
containerPort: 8080
- name: ajp
containerPort: 8009
创建和查看
[root@master ingress]# kubectl apply -f tomcat-deploy.yaml
service/tomcat created
deployment.apps/tomcat-depoly created
[root@master ingress]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
myapp-deploy-55b78d8548-b4c2c 1/1 Running 0 43h 10.244.3.29 node01.kubernetes <none> <none>
myapp-deploy-55b78d8548-gpdw8 1/1 Running 0 43h 10.244.1.26 node03.kubernetes <none> <none>
myapp-deploy-55b78d8548-hr6vx 1/1 Running 0 43h 10.244.2.22 node02.kubernetes <none> <none>
tomcat-depoly-579d97b849-66wrh 1/1 Running 0 7s 10.244.3.30 node01.kubernetes <none> <none>
tomcat-depoly-579d97b849-rh5r6 1/1 Running 0 7s 10.244.1.28 node03.kubernetes <none> <none>
tomcat-depoly-579d97b849-sd49w 1/1 Running 0 7s 10.244.2.23 node02.kubernetes <none> <none>
[root@master ingress]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 22d
myapp ClusterIP 10.111.44.7 <none> 80/TCP 76m
tomcat ClusterIP 10.106.39.78 <none> 8080/TCP,8009/TCP 3m18s
创建 tomcat-ingress
[root@master ingress]# cat ingress-tomcat.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: ingress-tomcat
namespace: default
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
rules:
- host: tomcat.beijingfc.com
http:
paths:
- path:
backend:
serviceName: tomcat
servicePort: 8080
创建和查看
[root@master ingress]# kubectl apply -f ingress-tomcat.yaml
ingress.extensions/ingress-tomcat created
[root@master ingress]# kubectl get ing
NAME HOSTS ADDRESS PORTS AGE
ingress-myapp myapp.beijingfc.com 80 53m
ingress-tomcat tomcat.beijingfc.com 80 4s
测试访问 tomcat
注意,同样写Hosts 之后进行测试
[root@xinguan-test-node1 ~]# grep tomcat /etc/hosts
10.0.20.20 myapp.beijingfc.com tomcat.beijingfc.com
[root@xinguan-test-node1 ~]# curl tomcat.beijingfc.com:30080
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>Apache Tomcat/8.5.32</title>
<link href="favicon.ico" rel="icon" type="image/x-icon" />
<link href="favicon.ico" rel="shortcut icon" type="image/x-icon" />
<link href="tomcat.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="wrapper">
<div id="navigation" class="curved container">
<span id="nav-home"><a href="http://tomcat.apache.org/">Home</a></span>
<span id="nav-hosts"><a href="/docs/">Documentation</a></span>
<span id="nav-config"><a href="/docs/config/">Configuration</a></span>
<span id="nav-examples"><a href="/examples/">Examples</a></span>
<span id="nav-wiki"><a href="http://wiki.apache.org/tomcat/FrontPage">Wiki</a></span>
<span id="nav-lists"><a href="http://tomcat.apache.org/lists.html">Mailing Lists</a></span>
<span id="nav-help"><a href="http://tomcat.apache.org/findhelp.html">Find Help</a></span>
<br class="separator" />
</div>
<div id="asf-box">
<h1>Apache Tomcat/8.5.32</h1>
</div>
... ...
... ...
模拟测试 Https
模拟测试 通过Ingress 的七层代理,访问Https,通过Ingress卸载证书后访问后端
所有先需要手动自签SSL证书
自签SSL证书
[root@master https]# openssl genrsa -out tls.key 2048
Generating RSA private key, 2048 bit long modulus
...............................+++
.....................................................................................................................................+++
e is 65537 (0x10001)
[root@master https]# openssl req -new -x509 -key tls.key -out tls.crt -subj /C=CN/ST=BeiJing/L=BeiJing/O=DefOps/CN=tomcat.beijingfc.com
[root@master https]# ll
total 8
-rw-r--r-- 1 root root 1302 Aug 1 11:33 tls.crt
-rw-r--r-- 1 root root 1675 Aug 1 11:31 tls.key
自签证书完成
创建secret
注意,此证书不能直接帖进去,需要先创建成secret,才能应用到Ingress中
[root@master https]# kubectl create secret tls tomcat-ingress-secret --cert=tls.crt --key=tls.key
secret/tomcat-ingress-secret created
[root@master https]# kubectl get secret
NAME TYPE DATA AGE
default-token-bc86p kubernetes.io/service-account-token 3 22d
tomcat-ingress-secret kubernetes.io/tls 2 10s
[root@master https]# kubectl describe secret tomcat-ingress-secret
Name: tomcat-ingress-secret
Namespace: default
Labels: <none>
Annotations: <none>
Type: kubernetes.io/tls
Data
====
tls.key: 1675 bytes
tls.crt: 1302 bytes
创建tls的https清单文件
[root@master https]# cat ingress-tomcat-tls.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: ingress-tomcat-tls
namespace: default
annotations:
kubernetes.io/ingress.class: "nginx"
spec:
tls:
- hosts:
- tomcat.beijingfc.com
secretName: tomcat-ingress-secret # 这里指定刚刚创建的secret名称
rules:
- host: tomcat.beijingfc.com
http:
paths:
- path:
backend:
serviceName: tomcat
servicePort: 8080
创建和查看
[root@master https]# kubectl apply -f ingress-tomcat-tls.yaml
ingress.extensions/ingress-tomcat-tls created
[root@master https]# kubectl get ing
NAME HOSTS ADDRESS PORTS AGE
ingress-myapp myapp.beijingfc.com 80 174m
ingress-tomcat tomcat.beijingfc.com 80 121m
ingress-tomcat-tls tomcat.beijingfc.com 80, 443 4s # 这里看到被创建成功
[root@master https]# kubectl describe ingress ingress-tomcat-tls
Name: ingress-tomcat-tls
Namespace: default
Address:
Default backend: default-http-backend:80 (<none>)
TLS:
tomcat-ingress-secret terminates tomcat.beijingfc.com
Rules:
Host Path Backends
---- ---- --------
tomcat.beijingfc.com
tomcat:8080 (10.244.1.28:8080,10.244.2.23:8080,10.244.3.30:8080)
Annotations:
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"extensions/v1beta1","kind":"Ingress","metadata":{"annotations":{"kubernetes.io/ingress.class":"nginx"},"name":"ingress-tomcat-tls","namespace":"default"},"spec":{"rules":[{"host":"tomcat.beijingfc.com","http":{"paths":[{"backend":{"serviceName":"tomcat","servicePort":8080},"path":null}]}}],"tls":[{"hosts":["tomcat.beijingfc.com"],"secretName":"tomcat-ingress-secret"}]}}
kubernetes.io/ingress.class: nginx
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal CREATE 26s nginx-ingress-controller Ingress default/ingress-tomcat-tls
测试访问
此时就已经完成,可以测试访问
因前面测试hosts已经写好