Istio的自定义资源有五十多个，今天先对Network部分的VirtualService的学习做个记录。
介绍
首先献上官方文档：https://istio.io/latest/zh/docs/reference/config/networking/virtual-service/
VirtualService主要是定义了服务的路由规则，如果流量满足了我们设定的匹配规则，则会根据我们的设定将流量发送到服务注册表中的服务/版本
样例
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: reviews-route
spec:
# host为必要字段，表示目标主机，尽量使用FQDN来进行服务引用，同个命名空间可以使用服务的短名称
hosts:
- reviews.prod.svc.cluster.local
# HTTP的有序路由规则列表，对httpx，http2x，grpc，都是有效的，匹配规则从上往下
http:
- name: "reviews-v2-routes"
# 匹配规则，有根据uri，header，host，port，queryParams，scheme等
# 匹配规则有：exact精准匹配，prefix前缀匹配，regex正则匹配
match:
- uri:
exact: "/wpcatalog"
- uri:
prefix: "/consumercatalog"
# 重写HTTP URI和Authority标头。重写将在转发之前执行。
rewrite:
uri: "/newcatalog"
# 重定向，重定向不能与重写一起使用
redirect:
uri: /v1/bookRatings
authority: newratings.default.svc.cluster.local
route:
- destination:
host: reviews.prod.svc.cluster.local
subset: v2
# 权重
weight: 80
- name: "reviews-v1-route"
route:
- destination:
host: reviews.prod.svc.cluster.local
subset: v1
# cors
corsPolicy:
allowOrigin:
- example.com
allowMethods:
- POST
- GET
allowCredentials: false
allowHeaders:
- X-Foo-Bar
maxAge: "24h"
# 应用到路由的网关，忽略默认使用默认网关
gateways:
- mygateway
# 透传TLS和HTTPS的流量的路由规则列表
tls:
- match:
- port: 443
sniHosts:
- login.bookinfo.com
route:
- destination:
host: login.prod.svc.cluster.local
# 透传tcp流量的有序路由规则列表，对所有HTTP和TLS之外的端口生效
tcp:
- match:
- port: 27017
route:
- destination:
host: mongo.backup.svc.cluster.local
port:
number: 5555
演示
创建两个对应的http server
httpd：
apiVersion: apps/v1
kind: Deployment
metadata:
name: httpd
labels:
server: httpd
app: web
spec:
replicas: 1
selector:
matchLabels:
server: httpd
app: web
template:
metadata:
labels:
server: httpd
app: web
spec:
containers:
- name: busybox
image: busybox
imagePullPolicy: IfNotPresent
command: ["/bin/sh", "-c", "echo 'this is httpd' > /var/www/index.html; httpd -f -p 8080 -h /var/www"]
---
apiVersion: v1
kind: Service
metadata:
name: httpd-svc
spec:
selector:
server: httpd
ports:
- name: http
port: 8080
targetPort: 8080
protocol: TCP
tomcat
apiVersion: apps/v1
kind: Deployment
metadata:
name: tomcat
labels:
server: tomcat
app: web
spec:
replicas: 1
selector:
matchLabels:
server: tomcat
app: web
template:
metadata:
labels:
server: tomcat
app: web
spec:
containers:
- name: tomcat
image: docker.io/kubeguide/tomcat-app:v1
imagePullPolicy: IfNotPresent
---
apiVersion: v1
kind: Service
metadata:
name: tomcat-svc
spec:
selector:
server: tomcat
ports:
- name: http
port: 8080
targetPort: 8080
protocol: TCP
Busy box进入容器中测试
apiVersion: apps/v1
kind: Deployment
metadata:
name: hexiaohong-client
spec:
replicas: 1
selector:
matchLabels:
app: hexiaohong-client
template:
metadata:
labels:
app: hexiaohong-client
spec:
containers:
- name: busybox
image: busybox
imagePullPolicy: IfNotPresent
command: ["/bin/sh", "-c", "sleep 3600"]
---
apiVersion: v1
kind: Service
metadata:
name: web-svc
spec:
selector:
app: hexiaohong-client
ports:
- name: http
port: 8080
targetPort: 8080
protocol: TCP
进入busybox测试
- httpd
- tomcat
创建VirtualService实现流控
创建VirtualService
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: web-svc-vs
spec:
hosts:
- web-svc.default.svc.cluster.local
http:
- route:
- destination:
host: httpd-svc
weight: 80
- destination:
host: tomcat-svc
weight: 20
- 查看VirtualService：
# kubectl get virtualservices.networking.istio.io
NAME GATEWAYS HOSTS AGE
bookinfo ["bookinfo-gateway"] ["*"] 31h
web-svc-vs ["web-svc.default.svc.cluster.local"] 43s
- 80%流量到httpd，20%到tomcat
创建VirtualService实现路由
创建带匹配条件的VirtualService
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: web-svc-vs
spec:
hosts:
- web-svc.default.svc.cluster.local
http:
- match:
- headers:
to:
exact: httpd
route:
- destination:
host: httpd-svc
- route:
- destination:
host: tomcat-svc
- 携带header:'to: httpd'将流量导入httpd，否则则到tomcat
