在Kubernetes集群中搭建Istio微服务网格的过程详解

1.设置主机名
hostnamectl set-hostname k8s-master
hostnamectl set-hostname k8s-node1
hostnamectl set-hostname k8s-node2
2.关闭selinux及防火墙
setenforce 0
sed -ri '/^SELINUX=/c SELINUX=disabled' /etc/sysconfig/selinux 
sed -ri '/^SELINUX=/c SELINUX=disabled' /etc/selinux/config 
systemctl stop firewalld
systemctl disable firewalld

1.sealos官网获取软件包
[root@k8s-master1 ~]# ll
总用量 507472
-rw-r--r-- 1 root root  552591411 8月   5 2021 kube1.19.16.tar.gz
-rw-r--r-- 1 root root  44322816  4月  29 13:47 sealos
2.将kube1.19.16.tar.gz文件上传到所有k8s节点
3.安装sealos
[root@k8s-master1 ~/soft]# chmod +x sealos && mv sealos /usr/bin
[root@k8s-master1 ~/soft]# sealos version
Version: 3.3.9-rc.3
Last Commit: 4db4953
Build Date: 2021-04-10T11:25:04Z
4.部署K8S1.19.16版本
[root@k8s-master ~]# sealos init --passwd 'teacher' --master 192.168.20.10  --node 192.168.20.11  --node 192.168.20.12 --pkg-url /root/kube1.19.16.tar.gz --version v1.19.16

[root@k8s-master ~]# curl -L https://istio.io/downloadIstio | ISTIO_VERSION=1.8.2 TARGET_ARCH=x86_64 sh -

1.准备istio命令
[root@k8s-master ~]# cp istio-1.8.2/bin/istioctl /usr/bin/
2.查看可用的配置列表
[root@k8s-master ~]# istioctl profile list
Istio configuration profiles:
    default					#默认配置档，功能丰富，建议生产使用
    demo					#快速入门使用，适中配置，不适合性能测试
    empty
    minimal					#功能最少的组件集配置
    openshift
    preview
    remote					#用于配置共享控制平面的多集群服务网格
3.指定安装的配置档
$ istioctl install --set profile=demo -y

1.安装istio
[root@k8s-master ~]# istioctl install -y
Detected that your cluster does not support third party JWT authentication. Falling back to less secure first party JWT. See https://istio.io/v1.8/docs/ops/best-practices/security/#configure-third-party-service-account-tokens for details.
✔ Istio core installed
✔ Istiod installed                              
✔ Ingress gateways installed                              
✔ Installation complete        
2.查看istio在K8S集群创建的资源
[root@k8s-master ~]# kubectl get all -n istio-system
NAME                                        READY   STATUS    RESTARTS   AGE
pod/istio-ingressgateway-559f565fcd-jxn5b   1/1     Running   0          7m46s
pod/istiod-545bb98448-vqf84                 1/1     Running   0          12m

NAME                           TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)                                                                      AGE
service/istio-ingressgateway   LoadBalancer   10.107.107.206   <pending>     15021:32381/TCP,80:31105/TCP,443:30793/TCP,15012:32259/TCP,15443:31377/TCP   7m45s
service/istiod                 ClusterIP      10.109.130.252   <none>        15010/TCP,15012/TCP,443/TCP,15014/TCP                                        12m

NAME                                   READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/istio-ingressgateway   1/1     1            1           7m46s
deployment.apps/istiod                 1/1     1            1           12m

NAME                                              DESIRED   CURRENT   READY   AGE
replicaset.apps/istio-ingressgateway-559f565fcd   1         1         1       7m46s
replicaset.apps/istiod-545bb98448                 1         1         1       12m

NAME                                                       REFERENCE                         TARGETS         MINPODS   MAXPODS   REPLICAS   AGE
horizontalpodautoscaler.autoscaling/istio-ingressgateway   Deployment/istio-ingressgateway   <unknown>/80%   1         5         1          7m45s
horizontalpodautoscaler.autoscaling/istiod                 Deployment/istiod                 <unknown>/80%   1         5         1          12m

#程序部署了2个，分别是istiod以及istio-ingressgateway
#istio-ingressgateway的service资源通过loadblancer暴露了一组端口，我们可以通过这些端口访问到istio中的应用程序，loadblancer需要依靠公有云的负载均衡器，我们没有因此处于pending状态，但是该service资源也是可用的，loadblancer不存在公有云负载均衡器默认就会使用nodeport类型进行端口映射

[root@k8s-master ~]# istioctl profile dump default

#显示istio在k8s集群中部署使用的yaml编排文件内容
[root@k8s-master istio-1.8.2]# istioctl manifest generate 
#将编排文件内容导入到文件中
[root@k8s-master istio-1.8.2]# istioctl manifest generate > istio-generate.yaml
#后期不使用istio时，可以通过这个文件直接卸载istio
$ kubectl delete -f istio-generate.yaml