k8s 微服务 ingress-nginx 金丝雀发布
用控制器来完成集群的工作负载,那么应用如何暴漏出去?需要通过微服务暴漏出去后才能被访问Service是一组提供相同服务的Pod对外开放的接口。借助Service,应用可以实现服务发现和负载均衡。service默认只支持4层负载均衡能力,没有7层功能。(可以通过Ingress实现)金丝雀发布(Canary Release)也称为灰度发布,是一种软件发布策略。主要目的是在将新版本的软件全面推广到生产环
目录
一 什么是微服务
用控制器来完成集群的工作负载,那么应用如何暴漏出去?需要通过微服务暴漏出去后才能被访问
-
Service是一组提供相同服务的Pod对外开放的接口。
-
借助Service,应用可以实现服务发现和负载均衡。
-
service默认只支持4层负载均衡能力,没有7层功能。(可以通过Ingress实现)
二 微服务的类型
微服务类型 | 作用描述 |
---|---|
ClusterIP | 默认值,k8s系统给service自动分配的虚拟IP,只能在集群内部访问 |
NodePort | 将Service通过指定的Node上的端口暴露给外部,访问任意一个NodeIP:nodePort都将路由到ClusterIP |
LoadBalancer | 在NodePort的基础上,借助cloud provider创建一个外部的负载均衡器,并将请求转发到 NodeIP:NodePort,此模式只能在云服务器上使用 |
ExternalName | 将服务通过 DNS CNAME 记录方式转发到指定的域名(通过 spec.externlName 设定 |
示例:
#生成控制器文件并建立控制器
[root@k8s-master ~]# kubectl create deployment howe --image myapp:v1 --replicas 2 --dry-run=client -o yaml > howe.yml
[root@k8s-master ~]# kubectl apply -f howe.yml
deployment.apps/howe created
#生成微服务yaml追加到已有yaml中
[root@k8s-master ~]# kubectl expose deployment howe --port 80 --target-port 80 --dry-run=client -o yaml >> howe.yml
[root@k8s-master ~]# vim howe.yml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: howe
name: howe
spec:
replicas: 2
selector:
matchLabels:
app: howe
template:
metadata:
creationTimestamp: null
labels:
app: howe
spec:
containers:
- image: myapp:v1
name: myapp
--- #不同资源间用---隔开
apiVersion: v1
kind: Service
metadata:
labels:
app: howe
name: howe
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: howe
[root@k8s-master ~]# kubectl apply -f howe.yml
deployment.apps/howe created
service/howe created
[root@k8s-master ~]# kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
howe ClusterIP 10.99.113.82 <none> 80/TCP 32s
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d22h
微服务默认使用iptables调度
[root@k8s-master ~]# kubectl get services -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
howe ClusterIP 10.98.224.15 <none> 80/TCP 21m app=howe
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d23h <none>
#可以在火墙中查看到策略信息
[root@k8s-master ~]# iptables -t nat -nL
三 ipvs模式
-
Service 是由 kube-proxy 组件,加上 iptables 来共同实现的
-
kube-proxy 通过 iptables 处理 Service 的过程,需要在宿主机上设置相当多的 iptables 规则,如果宿主机有大量的Pod,不断刷新iptables规则,会消耗大量的CPU资源
-
IPVS模式的service,可以使K8s集群支持更多量级的Pod
3.1 ipvs模式配置方式
1 在所有节点中安装ipvsadm
[root@k8s-所有节点~]# yum install ipvsadm -y
2 修改master节点的代理配置
2.修改master节点的代理配置
[root@k8s-master ~]# kubectl -n kube-system edit cm kube-proxy
58 metricsBindAddress: ""
59 mode: "ipvs" #改为ipvs
60 nftables:
3 重启pod,在pod运行时配置文件中采用默认配置,当改变配置文件后已经运行的pod状态不会变化,所以要重启pod
[root@k8s-master ~]# kubectl -n kube-system get pods | awk '/kube-proxy/{system("kubectl -n kube-system delete pods "$1)}'
pod "kube-proxy-2484q" deleted
pod "kube-proxy-522xr" deleted
pod "kube-proxy-9gntr" deleted
[root@k8s-master ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 10.96.0.1:443 rr
-> 172.25.250.100:6443 Masq 1 0 0
TCP 10.96.0.10:53 rr
-> 10.244.0.2:53 Masq 1 0 0
-> 10.244.0.3:53 Masq 1 0 0
TCP 10.96.0.10:9153 rr
-> 10.244.0.2:9153 Masq 1 0 0
-> 10.244.0.3:9153 Masq 1 0 0
TCP 10.98.224.15:80 rr
-> 10.244.1.8:80 Masq 1 0 0
-> 10.244.2.11:80 Masq 1 0 0
UDP 10.96.0.10:53 rr
-> 10.244.0.2:53 Masq 1 0 0
-> 10.244.0.3:53 Masq 1 0 0
Note:切换ipvs模式后,kube-proxy会在宿主机上添加一个虚拟网卡:kube-ipvs0,并分配所有service IP
[root@k8s-master ~]# ip a | tail
inet6 fe80::ec14:d7ff:fec9:51d0/64 scope link
valid_lft forever preferred_lft forever
8: kube-ipvs0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default
link/ether f6:61:15:99:d6:74 brd ff:ff:ff:ff:ff:ff
inet 10.98.224.15/32 scope global kube-ipvs0
valid_lft forever preferred_lft forever
inet 10.96.0.1/32 scope global kube-ipvs0
valid_lft forever preferred_lft forever
inet 10.96.0.10/32 scope global kube-ipvs0
valid_lft forever preferred_lft forever
四 微服务类型详解
4.1 clusterip
特点:
clusterip模式只能在集群内访问,并对集群内的pod提供健康检测和自动发现功能
示例:
[root@k8s-master ~]# vim myapp.yml
---
apiVersion: v1
kind: Service
metadata:
labels:
app: howe
name: clusterip
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: howe
type: ClusterIP
[root@k8s-master ~]# kubectl apply -f howe.yml
deployment.apps/howe created
service/clusterip created
[root@k8s-master ~]# kubectl -n kube-system get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 3d2h
#解析
[root@k8s-master ~]# dig howe.default.svc.cluster.local. @10.96.0.10
; <<>> DiG 9.16.23-RH <<>> howe.default.svc.cluster.local. @10.96.0.10
;; global options: +cmd
;; Got answer:
;; WARNING: .local is reserved for Multicast DNS
;; You are currently testing what happens when an mDNS query is leaked to DNS
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58560
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: a103f7adf3299930 (echoed)
;; QUESTION SECTION:
;howe.default.svc.cluster.local. IN A
;; ANSWER SECTION:
howe.default.svc.cluster.local. 30 IN A 10.99.13.95
;; Query time: 3 msec
;; SERVER: 10.96.0.10#53(10.96.0.10)
;; WHEN: Fri Sep 06 14:24:57 CST 2024
;; MSG SIZE rcvd: 117
4.2 ClusterIP中的特殊模式headless
headless(无头服务)
对于无头Services并不会分配 Cluster IP,kube-proxy不会处理它们, 而且平台也不会为它们进行负载均衡和路由,集群访问通过dns解析直接指向到业务pod上的IP,所有的调度有dns单独完成
---
apiVersion: v1
kind: Service
metadata:
labels:
app: howe
name: superhowe
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: howe
type: ClusterIP
clusterIP: None
[root@k8s-master ~]# kubectl apply -f howe.yml
deployment.apps/howe unchanged
service/superhowe created
[root@k8s-master ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
howe-7b74f758bd-6k5xr 1/1 Running 0 7m6s 10.244.57.221 k8s-node1.exam.com <none> <none>
howe-7b74f758bd-wb97k 1/1 Running 0 7m6s 10.244.57.222 k8s-node1.exam.com <none> <none>
[root@k8s-master ~]# kubectl get services superhowe
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
superhowe ClusterIP None <none> 80/TCP 36s
[root@k8s-master ~]# dig superhowe.default.svc.cluster.local. @10.96.0.10
; <<>> DiG 9.16.23-RH <<>> superhowe.default.svc.cluster.local. @10.96.0.10
;; global options: +cmd
;; Got answer:
;; WARNING: .local is reserved for Multicast DNS
;; You are currently testing what happens when an mDNS query is leaked to DNS
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43354
;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: 4bb1245f5b902f9b (echoed)
;; QUESTION SECTION:
;superhowe.default.svc.cluster.local. IN A
;; ANSWER SECTION:
superhowe.default.svc.cluster.local. 30 IN A 10.244.57.222 #直接解析到pod上
superhowe.default.svc.cluster.local. 30 IN A 10.244.57.221
;; Query time: 30 msec
;; SERVER: 10.96.0.10#53(10.96.0.10)
;; WHEN: Tue Sep 10 12:32:26 CST 2024
;; MSG SIZE rcvd: 178
#开启一个busyboxplus的pod测试
[root@k8s-master ~]# kubectl run test --image busyboxplus -it
If you don't see a command prompt, try pressing enter.
/ # nslookup superhowe
Server: 10.96.0.10
Address 1: 10.96.0.10 kube-dns.kube-system.svc.cluster.local
Name: superhowe
Address 1: 10.244.57.227 10-244-57-227.superhowe.default.svc.cluster.local
Address 2: 10.244.57.226 10-244-57-226.superhowe.default.svc.cluster.local
/ #
/ # curl superhowe
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
/ # curl superhowe/hostname.html
howe-7b74f758bd-pnmpg
/ #
4.3 nodeport
通过ipvs暴漏端口从而使外部主机通过master节点的对外ip:<port>来访问pod业务
其访问过程为:
示例:
---
apiVersion: v1
kind: Service
metadata:
labels:
app: howe-service
name: howe-service
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: howe
type: NodePort
[root@k8s-master ~]# kubectl apply -f howe.yml
deployment.apps/howe created
service/howe-service created
[root@k8s-master ~]# kubectl get services howe-service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
howe-service NodePort 10.96.182.56 <none> 80:31502/TCP 26s
nodeport在集群节点上绑定端口,一个端口对应一个服务
[root@k8s-master ~]# for i in {1..5}
> do
> curl 172.25.250.100:31771/hostname.html
> done
howe-service-c56f584cf-fjxdk
howe-service-c56f584cf-5m2z5
howe-service-c56f584cf-z2w4d
howe-service-c56f584cf-tt5g6
howe-service-c56f584cf-fjxdk
Note:
nodeport默认端口
nodeport默认端口是30000-32767,超出会报错
[root@k8s-master ~]# vim timinglee.yaml
apiVersion: v1
kind: Service
metadata:
labels:
app: timinglee-service
name: timinglee-service
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
nodePort: 33333
selector:
app: timinglee
type: NodePort
[root@k8s-master ~]# kubectl apply -f timinglee.yaml
deployment.apps/timinglee created
The Service "timinglee-service" is invalid: spec.ports[0].nodePort: Invalid value: 33333: provided port is not in the valid range. The range of valid ports is 30000-32767
如果需要使用这个范围以外的端口就需要特殊设定
[root@k8s-master ~]# vim /etc/kubernetes/manifests/kube-apiserver.yaml
- --service-node-port-range=30000-40000
NOTE:
添加“--service-node-port-range=“ 参数,端口范围可以自定义
修改后api-server会自动重启,等apiserver正常启动后才能操作集群
集群重启自动完成在修改完参数后全程不需要人为干预
4.4 loadbalancer
云平台会为我们分配vip并实现访问,如果是裸金属主机那么需要metallb来实现ip的分配
LoadBalancer模式适用云平台,裸金属环境需要安装metallb提供支持
[root@k8s-master ~]# vim loadbalancer.yaml
---
apiVersion: v1
kind: Service
metadata:
labels:
app: howe-service
name: loadbalancer
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: howe
type: LoadBalancer
[root@k8s-master ~]#
[root@k8s-master ~]# kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
loadbalancer LoadBalancer 10.99.217.26 172.25.250.50 80:30908/TCP 12s
4.5 metalLB
官网:Installation :: MetalLB, bare metal load-balancer for Kubernetes
metalLB功能:
为LoadBalancer分配vip
1.设置ipvs模式
[root@k8s-master ~]# kubectl edit cm -n kube-system kube-proxy
44 strictARP: true
59 mode: "ipvs"
2.下载部署文件
wget https://raw.githubusercontent.com/metallb/metallb/v0.13.12/config/manifests/metallb-native.yaml
[root@k8s-master metallb]# ls
configmap.yml metallb-native.yaml metalLB.tag.gz
[root@k8s-master metallb]# docker load -i metalLB.tag.gz
3.修改文件中镜像地址,与harbor仓库路径保持一致
[root@k8s-master ~]# vim metallb-native.yaml
...
image: metallb/controller:v0.14.8
image: metallb/speaker:v0.14.8
4.上传镜像到harbor
[root@k8s-master ~]# docker tag quay.io/metallb/speaker:v0.14.8 reg.exam.com/metallb/speaker:v0.14.8
[root@k8s-master ~]# docker tag quay.io/metallb/controller:v0.14.8 reg.exam.com/metallb/controller:v0.14.8
[root@k8s-master ~]# docker push reg.exam.com/metallb/speaker:v0.14.8
[root@k8s-master ~]# docker push reg.exam.com/metallb/controller:v0.14.8
部署服务
[root@k8s-master ~]# kubectl apply -f metallb-native.yaml
[root@k8s-master metalLB]# kubectl -n metallb-system get pods
NAME READY STATUS RESTARTS AGE
controller-65957f77c8-spdkq 1/1 Running 0 28s
speaker-8wgsh 1/1 Running 0 28s
speaker-ct8ld 1/1 Running 0 28s
speaker-w7699 1/1 Running 0 28s
配置分配地址段
[root@k8s-master ~]# vim configmap.yml
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
name: first-pool
namespace: metallb-system
spec:
addresses:
- 172.25.250.50-172.25.250.99 #修改为自己本地地址段
--- #两个不同的kind中间必须加分割
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
name: example
namespace: metallb-system
spec:
ipAddressPools:
- first-pool #使用地址池
[root@k8s-master ~]# kubectl apply -f configmap.yml
ipaddresspool.metallb.io/first-pool created
l2advertisement.metallb.io/example created
[root@k8s-master ~]# kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
clusterip ClusterIP 10.100.145.164 <none> 80/TCP 43h
howe ClusterIP 10.99.13.95 <none> 80/TCP 43h
howe-service NodePort 10.96.182.56 <none> 80:31502/TCP 42h
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 4d21h
loadbalancer LoadBalancer 10.99.217.26 172.25.250.50 80:30908/TCP 94s
#通过分配地址从集群外访问服务
[root@k8s-master ~]# curl 172.25.250.50
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
4.6 externalname
-
开启services后,不会被分配IP,而是用dns解析CNAME固定域名来解决ip变化问题
-
一般应用于外部业务和pod沟通或外部业务迁移到pod内时
-
在应用向集群迁移过程中,externalname在过度阶段就可以起作用了。
-
集群外的资源迁移到集群时,在迁移的过程中ip可能会变化,但是域名+dns解析能完美解决此问题
示例:
---
apiVersion: v1
kind: Service
metadata:
labels:
app: howe-service
name: ExternalName
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: howe
type: ExternalName
externalName: www.baidu.com
[root@k8s-master ~]# kubectl get services howe-service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
howe-service ExternalName <none> www.baidu.com 80/TCP 14s
五 Ingress-nginx
官网:
Installation Guide - Ingress-Nginx Controller
5.1 ingress-nginx功能
-
一种全局的、为了代理不同后端 Service 而设置的负载均衡服务,支持7层
-
Ingress由两部分组成:Ingress controller和Ingress服务
-
Ingress Controller 会根据你定义的 Ingress 对象,提供对应的代理能力。
-
业界常用的各种反向代理项目,比如 Nginx、HAProxy、Envoy、Traefik 等,都已经为Kubernetes 专门维护了对应的 Ingress Controller。
5.2 部署ingress
5.2.1 下载部署文件
[root@k8s-master ~]# wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.11.2/deploy/static/provider/baremetal/deploy.yaml
上传ingress所需镜像到harbor
[root@k8s-master ~]# docker tag reg.harbor.org/ingress-nginx/controller:v1.11.2 reg.exam.com/ingress-nginx/controller:v1.11.2
[root@k8s-master ~]# docker push reg.exam.com/ingress-nginx/controller:v1.11.2
[root@k8s-master ~]# docker tag reg.harbor.org/ingress-nginx/kube-webhook-certgen:v1.4.3 reg.exam.com/ingress-nginx/kube-webhook-certgen:v1.4.3
[root@k8s-master ~]# docker push reg.exam.com/ingress-nginx/kube-webhook-certgen:v1.4.3
5.2.2 安装ingress
[root@k8s-master ~]# vim deploy.yaml
445 image: ingress-nginx/controller:v1.11.2
546 image: ingress-nginx/kube-webhook-certgen:v1.4.3
599 image: ingress-nginx/kube-webhook-certgen:v1.4.3
[root@k8s-master ~]# kubectl apply -f deploy.yaml
namespace/ingress-nginx created
serviceaccount/ingress-nginx created
serviceaccount/ingress-nginx-admission created
role.rbac.authorization.k8s.io/ingress-nginx created
role.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrole.rbac.authorization.k8s.io/ingress-nginx created
clusterrole.rbac.authorization.k8s.io/ingress-nginx-admission created
rolebinding.rbac.authorization.k8s.io/ingress-nginx created
rolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx created
clusterrolebinding.rbac.authorization.k8s.io/ingress-nginx-admission created
configmap/ingress-nginx-controller created
service/ingress-nginx-controller created
service/ingress-nginx-controller-admission created
deployment.apps/ingress-nginx-controller created
job.batch/ingress-nginx-admission-create created
job.batch/ingress-nginx-admission-patch created
ingressclass.networking.k8s.io/nginx created
validatingwebhookconfiguration.admissionregistration.k8s.io/ingress-nginx-admission created
[root@k8s-master ~]# kubectl -n ingress-nginx get pods
NAME READY STATUS RESTARTS AGE
ingress-nginx-admission-create-n2txq 0/1 Completed 0 29s
ingress-nginx-admission-patch-r8cpf 0/1 Completed 1 29s
ingress-nginx-controller-bb7d8f97c-56frl 1/1 Running 0 29s
[root@k8s-master ~]# kubectl -n ingress-nginx get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-nginx-controller NodePort 10.101.239.212 <none> 80:30311/TCP,443:31161/TCP 62s
ingress-nginx-controller-admission ClusterIP 10.109.186.61 <none> 443/TCP 62s
#修改微服务为loadbalancer
[root@k8s-master ~]# kubectl -n ingress-nginx edit svc ingress-nginx-controller
49 type: LoadBalancer
[root@k8s-master ~]# kubectl -n ingress-nginx get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
ingress-nginx-controller LoadBalancer 10.101.36.67 172.25.250.50 80:31025/TCP,443:30477/TCP 2m5s
ingress-nginx-controller-admission ClusterIP 10.111.255.211 <none> 443/TCP 2m5s
Note:在ingress-nginx-controller中看到的对外IP就是ingress最终对外开放的ip
5.2.3 测试ingress
#生成yaml文件
[root@k8s-master ~]# kubectl create ingress webcluster --rule '*/=howe-svc:80' --dry-run=client -o yaml > howe-ingress.yml
[root@k8s-master ~]# vim howe-ingress.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: test-ingress
spec:
ingressClassName: nginx
rules:
- http:
paths:
- backend:
service:
name: howe-svc
port:
number: 80
path: /
pathType: Prefix
#Exact(精确匹配),ImplementationSpecific(特定实现),Prefix(前缀匹配),Regular expression(正则表达式匹配)
#建立ingress控制器
[root@k8s-master ~]# kubectl apply -f howe-ingress.yml
ingress.networking.k8s.io/test-ingress created
[root@k8s-master ~]# kubectl get ingress
NAME CLASS HOSTS ADDRESS PORTS AGE
test-ingress nginx * 172.25.250.20 80 81s
[root@k8s-master ~]# for i in {1..5};
> do
> curl 172.25.250.50/hostname.html;
> done
howe-7b74f758bd-4vw2v
howe-7b74f758bd-jvb7q
howe-7b74f758bd-4vw2v
howe-7b74f758bd-jvb7q
howe-7b74f758bd-4vw2v
Note:ingress必须和输出的service资源处于同一namespace
5.3 ingress 的高级用法
5.3.1 基于路径的访问
1.建立用于测试的控制器myapp
[root@k8s-master ~]# kubectl create deployment myapp-v1 --image myapp:v1 --dry-run=client -o yaml > myapp-v1.yaml
[root@k8s-master ~]# kubectl create deployment myapp-v2 --image myapp:v2 --dry-run=client -o yaml > myapp-v2.yaml
[root@k8s-master ~]# vim myapp-v1.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: myapp-v1
name: myapp-v1
spec:
replicas: 1
selector:
matchLabels:
app: myapp-v1
strategy: {}
template:
metadata:
labels:
app: myapp-v1
spec:
containers:
- image: myapp:v1
name: myapp
---
apiVersion: v1
kind: Service
metadata:
labels:
app: myapp-v1
name: myapp-v1
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: myapp-v1
[root@k8s-master ~]# vim myapp-v2.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: myapp-v2
name: myapp-v2
spec:
replicas: 1
selector:
matchLabels:
app: myapp-v2
template:
metadata:
labels:
app: myapp-v2
spec:
containers:
- image: myapp:v2
name: myapp
---
apiVersion: v1
kind: Service
metadata:
labels:
app: myapp-v2
name: myapp-v2
spec:
ports:
- port: 80
protocol: TCP
targetPort: 80
selector:
app: myapp-v2
[root@k8s-master ~]# kubectl apply -f myapp-v1.yaml
deployment.apps/myapp-v1 created
service/myapp-v1 created
[root@k8s-master ~]# kubectl apply -f myapp-v2.yaml
deployment.apps/myapp-v2 created
service/myapp-v2 created
#端口暴露
[root@k8s-master ~]# kubectl expose deployment myapp-v1 --port 80 --target-port 80 --dry-run=client -o yaml >> myapp-v1.yaml
[root@k8s-master ~]# kubectl expose deployment myapp-v2 --port 80 --target-port 80 --dry-run=client -o yaml >> myapp-v2.yaml
[root@k8s-master ~]# kubectl get services
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 5d2h
myapp-v1 ClusterIP 10.99.69.251 <none> 80/TCP 6m10s
myapp-v2 ClusterIP 10.98.76.17 <none> 80/TCP 8s
[root@k8s-master ~]# curl 10.99.69.251
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-master ~]# curl 10.98.76.17
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
2.建立ingress的yaml
[root@k8s-master ~]# vim ingress1.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/rewrite-target: / #访问路径后加任何内容都被定向到/
name: ingress1
spec:
ingressClassName: nginx
rules:
- host: www.exam.com
http:
paths:
- backend:
service:
name: myapp-v1
port:
number: 80
path: /v1
pathType: Prefix
- backend:
service:
name: myapp-v2
port:
number: 80
path: /v2
pathType: Prefix
[root@k8s-master ~]# vim /etc/hosts
[root@k8s-master ~]# kubectl apply -f ingress1.yml
ingress.networking.k8s.io/ingress1 created
[root@k8s-master ~]# kubectl describe ingress ingress1
Name: ingress1
Labels: <none>
Namespace: default
Address: 172.25.250.20 #添加IP
Ingress Class: nginx
Default backend: <default>
Rules:
Host Path Backends
---- ---- --------
www.exam.com
/v1 myapp-v1:80 (10.244.1.10:80)
/v2 myapp-v2:80 (10.244.2.11:80)
Annotations: nginx.ingress.kubernetes.io/rewrite-target: /
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Sync 8m35s (x2 over 8m52s) nginx-ingress-controller Scheduled for sync
#测试:
[root@k8s-node1 ~]# echo 172.25.254.50 www.exam.com >> /etc/hosts
[root@k8s-node1 ~]# curl www.exam.com/v1
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-node1 ~]# curl www.exam.com/v2
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
#nginx.ingress.kubernetes.io/rewrite-target: / 的功能实现
[root@k8s-node1 ~]# curl www.exam.com/v1/aaaa
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
5.3.2 基于域名的访问
#在测试主机中设定解析
[root@k8s-node1 ~]# vim /etc/hosts
172.25.250.250 reg.exam.com
172.25.250.50 www.exam.com myappv1.exam.com myappv2.exam.com
# 建立基于域名的yml文件
[root@k8s-master ~]# vim ingress2.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
name: ingress2
spec:
ingressClassName: nginx
rules:
- host: myappv1.exam.com
http:
paths:
- backend:
service:
name: myapp-v1
port:
number: 80
path: /
pathType: Prefix
- host: myappv2.exam.com
http:
paths:
- backend:
service:
name: myapp-v2
port:
number: 80
path: /
pathType: Prefix
#利用文件建立ingress
[root@k8s-master ~]# kubectl apply -f ingress2.yml
ingress.networking.k8s.io/ingress2 created
[root@k8s-master ~]# kubectl describe ingress ingress2
Name: ingress2
Labels: <none>
Namespace: default
Address:
Ingress Class: nginx
Default backend: <default>
Rules:
Host Path Backends
---- ---- --------
myappv1.exam.com
/ myapp-v1:80 (10.244.1.12:80)
myappv2.exam.com
/ myapp-v2:80 (10.244.2.14:80)
Annotations: nginx.ingress.kubernetes.io/rewrite-target: /
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Sync 17s nginx-ingress-controller Scheduled for sync
#在测试主机中测试
[root@k8s-node1 ~]# curl www.exam.com/v1
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-node1 ~]# curl www.exam.com/v2
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
5.3.3 建立tls加密
#建立证书
[root@k8s-master ~]# openssl req -newkey rsa:2048 -nodes -keyout tls.key -x509 -days 365 -subj "/CN=nginxsvc/O=nginxsvc" -out tls.crt
#建立加密资源类型secret
[root@k8s-master ~]# kubectl create secret tls web-tls-secret --key tls.key --cert tls.crt
secret/web-tls-secret created
[root@k8s-master ~]# kubectl get secrets
NAME TYPE DATA AGE
web-tls-secret kubernetes.io/tls 2 3m41s
Note:secret通常在kubernetes中存放敏感数据,他并不是一种加密方式
#建立ingress3基于tls认证的yml文件
[root@k8s-master ~]# vim ingress3.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
name: ingress3
spec:
tls:
- hosts:
- www.exam.com
secretName: web-tls-secret
ingressClassName: nginx
rules:
- host: www.exam.com
http:
paths:
- backend:
service:
name: myapp-v1
port:
number: 80
path: /
pathType: Prefix
[root@k8s-master ~]# kubectl apply -f ingress3.yml
ingress.networking.k8s.io/ingress3 created
#测试
[root@k8s-node1 ~]# curl -k https://www.exam.com
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
5.3.4 建立auth认证
#建立认证文件
[root@k8s-master ~]# dnf install httpd-tools -y
[root@k8s-master ~]# htpasswd -cm auth howe
New password:
Re-type new password:
Adding password for user howe
[root@k8s-master ~]# cat auth
howe:$apr1$1F6Ny7Nx$/u.EcLHUia5jTPqT4X3zL1
#建立认证类型资源
[root@k8s-master ~]# kubectl create secret generic auth-web --from-file auth
secret/auth-web created
[root@k8s-master ~]# kubectl describe secrets auth-web
Name: auth-web
Namespace: default
Labels: <none>
Annotations: <none>
Type: Opaque
Data
====
auth: 43 bytes
#建立ingress4基于用户认证的yaml文件
[root@k8s-master ~]# vim ingress4.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/auth-type: basic
nginx.ingress.kubernetes.io/auth-secret: auth-web
nginx.ingress.kubernetes.io/auth-realm: "Please input username and password"
name: ingress4
spec:
tls:
- hosts:
- www.exam.com
secretName: web-tls-secret
ingressClassName: nginx
rules:
- host: www.exam.com
http:
paths:
- backend:
service:
name: myapp-v1
port:
number: 80
path: /
pathType: Prefix
[root@k8s-master ~]# kubectl apply -f ingress4.yml
ingress.networking.k8s.io/ingress4 created
[root@k8s-master ~]# kubectl describe ingress ingress4
Name: ingress4
Labels: <none>
Namespace: default
Address: 172.25.250.20
Ingress Class: nginx
Default backend: <default>
TLS:
web-tls-secret terminates www.exam.com
Rules:
Host Path Backends
---- ---- --------
www.exam.com
/ myapp-v1:80 (10.244.1.12:80)
Annotations: nginx.ingress.kubernetes.io/auth-realm: Please input username and password
nginx.ingress.kubernetes.io/auth-secret: auth-web
nginx.ingress.kubernetes.io/auth-type: basic
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Sync 2s (x2 over 18s) nginx-ingress-controller Scheduled for sync
#测试:
[root@k8s-node1 ~]# curl -k https://myappv1.exam.com -uhowe:redhat
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
5.3.5 rewrite重定向
#指定默认访问的文件到hostname.html上
[root@k8s-master ~]# vim ingress5.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/app-root: /hostname.html
nginx.ingress.kubernetes.io/auth-type: basic
nginx.ingress.kubernetes.io/auth-secret: auth-web
nginx.ingress.kubernetes.io/auth-realm: "Please input username and password"
name: ingress5
spec:
tls:
- hosts:
- www.exam.com
secretName: web-tls-secret
ingressClassName: nginx
rules:
- host: www.exam.com
http:
paths:
- backend:
service:
name: myapp-v1
port:
number: 80
path: /
pathType: Prefix
[root@k8s-master ~]# kubectl apply -f ingress5.yml
ingress.networking.k8s.io/ingress5 created
[root@k8s-master ~]# kubectl describe ingress ingress5
Name: ingress5
Labels: <none>
Namespace: default
Address:
Ingress Class: nginx
Default backend: <default>
TLS:
web-tls-secret terminates www.exam.com
Rules:
Host Path Backends
---- ---- --------
www.exam.com
/ myapp-v1:80 (10.244.1.12:80)
Annotations: nginx.ingress.kubernetes.io/app-root: /hostname.html
nginx.ingress.kubernetes.io/auth-realm: Please input username and password
nginx.ingress.kubernetes.io/auth-secret: auth-web
nginx.ingress.kubernetes.io/auth-type: basic
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Sync 21s nginx-ingress-controller Scheduled for sync
测试:
[root@k8s-node1 ~]# curl -Lk https://www.exam.com -uhowe:redhat
myapp-v1-7479d6c54d-dlz6f
[root@k8s-node1 ~]# curl -Lk https://www.exam.com/app/hostname.html -uhowe:redhat
<html>
<head><title>404 Not Found</title></head>
<body bgcolor="white">
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.12.2</center>
</body>
</html>
#解决重定向路径问题
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /$2
nginx.ingress.kubernetes.io/use-regex: "true"
nginx.ingress.kubernetes.io/auth-type: basic
nginx.ingress.kubernetes.io/auth-secret: auth-web
nginx.ingress.kubernetes.io/auth-realm: "Please input username and password"
name: ingress
spec:
tls:
- hosts:
- myappv1.exam.com
secretName: web-tls-secret
ingressClassName: nginx
rules:
- host: myappv1.exam.com
http:
paths:
- backend:
service:
name: myapp-v1
port:
number: 80
path: /
pathType: Prefix
- backend:
service:
name: myapp-v1
port:
number: 80
path: /app(/|$)(.*) #正则表达式匹配/app/,/app/abc
pathType: ImplementationSpecific
测试:
[root@k8s-node1 ~]# curl -Lk https://myappv1.exam.com/app/hostname.html -uhowe:redhat
myapp-v1-7479d6c54d-dlz6f
六 Canary金丝雀发布
6.1 什么是金丝雀发布
金丝雀发布(Canary Release)也称为灰度发布,是一种软件发布策略。
主要目的是在将新版本的软件全面推广到生产环境之前,先在一小部分用户或服务器上进行测试和验证,以降低因新版本引入重大问题而对整个系统造成的影响。
是一种Pod的发布方式。金丝雀发布采取先添加、再删除的方式,保证Pod的总量不低于期望值。并且在更新部分Pod后,暂停更新,当确认新Pod版本运行正常后再进行其他版本的Pod的更新。
6.2 Canary发布方式
其中header和weiht中的最多
6.2.1 基于header(http包头)灰度
-
通过Annotaion扩展
-
创建灰度ingress,配置灰度头部key以及value
-
灰度流量验证完毕后,切换正式ingress到新版本
-
之前我们在做升级时可以通过控制器做滚动更新,默认25%利用header可以使升级更为平滑,通过key 和vule 测试新的业务体系是否有问题。
示例:
#建立版本1的ingress
[root@k8s-master ~]# vim ingress7.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
name: myapp-v1-ingress
spec:
ingressClassName: nginx
rules:
- host: www.exam.com
http:
paths:
- backend:
service:
name: myapp-v1
port:
number: 80
path: /
pathType: Prefix
[root@k8s-master ~]# kubectl apply -f ingress7.yml
ingress.networking.k8s.io/myapp-v1-ingress created
[root@k8s-master ~]# kubectl describe ingress myapp-v1-ingress
Name: myapp-v1-ingress
Labels: <none>
Namespace: default
Address: 172.25.250.20
Ingress Class: nginx
Default backend: <default>
Rules:
Host Path Backends
---- ---- --------
www.exam.com
/ myapp-v1:80 (10.244.1.12:80)
Annotations: <none>
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Sync 78s (x2 over 116s) nginx-ingress-controller Scheduled for sync
#建立基于header的ingress
[root@k8s-master ~]# vim ingress8.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/canary: "true"
nginx.ingress.kubernetes.io/canary-by-header: "version"
nginx.ingress.kubernetes.io/canary-by-header-value: "2"
name: myapp-v2-ingress
spec:
ingressClassName: nginx
rules:
- host: www.exam.com
http:
paths:
- backend:
service:
name: myapp-v2
port:
number: 80
path: /
pathType: Prefix
[root@k8s-master ~]# kubectl apply -f ingress8.yml
ingress.networking.k8s.io/myapp-v2-ingress created
[root@k8s-master ~]# kubectl describe ingress myapp-v2-ingress
Name: myapp-v2-ingress
Labels: <none>
Namespace: default
Address: 172.25.250.20
Ingress Class: nginx
Default backend: <default>
Rules:
Host Path Backends
---- ---- --------
www.exam.com
/ myapp-v2:80 (10.244.2.14:80)
Annotations: nginx.ingress.kubernetes.io/canary: true
nginx.ingress.kubernetes.io/canary-by-header: version
nginx.ingress.kubernetes.io/canary-by-header-value: 2
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Sync 50s (x2 over 87s) nginx-ingress-controller Scheduled for sync
#测试:
[root@k8s-node1 ~]# curl www.exam.com
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@k8s-node1 ~]# curl -H "version: 2" www.exam.com
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
6.2.2 基于权重的灰度发布
-
通过Annotaion拓展
-
创建灰度ingress,配置灰度权重以及总权重
-
灰度流量验证完毕后,切换正式ingress到新版本
示例:
[root@k8s-master ~]# vim ingress8.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/canary: "true"
nginx.ingress.kubernetes.io/canary-weight: "10" #更改权重值
nginx.ingress.kubernetes.io/canary-weight-total: "100"
name: myapp-v2-ingress
spec:
ingressClassName: nginx
rules:
- host: www.exam.com
http:
paths:
- backend:
service:
name: myapp-v2
port:
number: 80
path: /
pathType: Prefix
#从机通过编写脚本测试:
[root@k8s-node1 ~]# vim check_ingress.sh
#!/bin/bash
v1=0
v2=0
for (( i=0; i<100; i++))
do
response=`curl -s www.exam.com |grep -c v1`
v1=`expr $v1 + $response`
v2=`expr $v2 + 1 - $response`
done
echo "v1:$v1, v2:$v2"
#运行脚本 #更改完毕权重后继续测试可观察变化
[root@k8s-node1 ~]# sh check_ingress.sh
v1:100, v2:0
[root@k8s-node1 ~]# sh check_ingress.sh
v1:80, v2:20
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