ArgoCD集成部署到Kubernetes

1：环境

kubernetes	1.23.3
ArgoCD	2.3.3

2：ArgoCD介绍

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. Argo CD是一个基于Kubernetes的声明式的GitOps工具。那么，什么是GitOps呢？ GitOps是以Git为基础，使用CI/CD来更新运行在云原生环境的应用，它秉承了DevOps的核心理念--“构建它并交付它(you built it you ship it)”。

它的优势总结如下：
1：应用定义、配置和环境信息是声明式的，并且可以进行版本控制；
2：应用部署和生命周期管理是全自动化的，是可审计的，清晰易懂；
3：Argo CD是一个独立的部署工具，支持对多个环境、多个Kubernetes集群上的应用进行统一部署和管理

3：部署ArgoCD

# 安装很简单，不过在实际使用中需要对数据进行持久化。

1：创建一个命名空间存放argocd的Pod
[root@k8s-master ~]# kubectl create ns argocd
namespace/argocd created

2：通过官方命令部署（镜像在国外，需要梯子，或者加速也行）
[root@k8s-master ~]# kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

3：查看部署状态
[root@k8s-master ~]# kubectl get pod,svc -n argocd
NAME                                                    READY   STATUS    RESTARTS   AGE
pod/argocd-application-controller-0                     1/1     Running   0          60s
pod/argocd-applicationset-controller-79f97597cb-mwzld   1/1     Running   0          62s
pod/argocd-dex-server-6fd8b59f5b-zx76f                  1/1     Running   0          62s
pod/argocd-notifications-controller-5549f47758-2rgjk    1/1     Running   0          61s
pod/argocd-redis-79bdbdf78f-xhd8f                       1/1     Running   0          61s
pod/argocd-repo-server-5569c7b657-t5ftv                 1/1     Running   0          61s
pod/argocd-server-664b7c6878-9tjlh                      1/1     Running   0          61s

4：因为需要访问，我们可以通过NodePort或者Ingress暴露 argocd-server
# 我这里使用 NodePort
# 但是我们需要修改一下argocd-server的暴露方式为NodePort
[root@k8s-master argocd]# kubectl edit svc -n argocd argocd-server
......
  selector:
    app.kubernetes.io/name: argocd-server
  sessionAffinity: None
  type: NodePort
status:
  loadBalancer: {}
[root@k8s-master argocd]# kubectl get svc -n argocd
NAME                                      TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                      AGE
argocd-applicationset-controller          ClusterIP   200.1.73.127    <none>        7000/TCP                     15m
argocd-dex-server                         ClusterIP   200.1.77.207    <none>        5556/TCP,5557/TCP,5558/TCP   15m
argocd-metrics                            ClusterIP   200.1.88.62     <none>        8082/TCP                     15m
argocd-notifications-controller-metrics   ClusterIP   200.1.185.23    <none>        9001/TCP                     15m
argocd-redis                              ClusterIP   200.1.5.40      <none>        6379/TCP                     15m
argocd-repo-server                        ClusterIP   200.1.249.26    <none>        8081/TCP,8084/TCP            15m
argocd-server                             NodePort    200.1.15.59     <none>        80:31715/TCP,443:30604/TCP   15m
argocd-server-metrics                     ClusterIP   200.1.216.113   <none>        8083/TCP                     15m

访问节点IP+30604即可

账号：admin
# 获取密码方式如下
[root@k8s-master argocd]# echo $(kubectl get secret -n argocd argocd-initial-admin-secret -o yaml | grep password | awk -F: '{print $2}') | base64 -d
密码：U8g9xqXAPIRz6Ds3

4：使用ArgoCD简单的做一个CD

# 这里我只展示CD并不接触CI

配置完成之后我们就可以创建项目了

准备项目yaml并上传到git仓库

[root@k8s-master flask]# cat demo.yaml 
apiVersion: v1
kind: Namespace
metadata:
  name: demo
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo
  namespace: demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      imagePullSecrets:
      - name: harbor
      containers:
      - name: demo
        image: registry.kubernetes-devops.cn/library/nginx:alpine
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: demo
  namespace: demo
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
  selector:
    app: demo
    
[root@k8s-master flask]# git add .
[root@k8s-master flask]# git commit -m "demo"
[master eddda10] demo
 1 file changed, 9 insertions(+), 9 deletions(-)
 rename nginx.yaml => demo.yaml (77%)
[root@k8s-master flask]# git push origin master 
Username for 'http://10.0.0.10:31179': devops
Password for 'http://devops@10.0.0.10:31179': 
Counting objects: 4, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 509 bytes | 0 bytes/s, done.
Total 3 (delta 0), reused 0 (delta 0)
remote: . Processing 1 references
remote: Processed 1 references in total
To http://10.0.0.10:31179/devops/flask.git
   d31d433..eddda10  master -> master

# 然后我们去ArgoCD去部署这个demo

我们查看一下部署情况，并看看部署之后是否可以访问

[root@k8s-master flask]# kubectl get pod,svc -n demo 
NAME                        READY   STATUS    RESTARTS   AGE
pod/demo-8645cf44c9-2pkv6   1/1     Running   0          84s

NAME           TYPE       CLUSTER-IP    EXTERNAL-IP   PORT(S)        AGE
service/demo   NodePort   200.1.73.45   <none>        80:30808/TCP   84s


# 测试访问
[root@k8s-master flask]# curl 10.0.0.10:30808 -I
HTTP/1.1 200 OK
Server: nginx/1.21.5
Date: Sat, 23 Apr 2022 12:46:29 GMT
Content-Type: text/html
Content-Length: 615
Last-Modified: Tue, 28 Dec 2021 18:48:00 GMT
Connection: keep-alive
ETag: "61cb5be0-267"
Accept-Ranges: bytes

这个时候我们去变更一下代码。（变更一下yaml）

[root@k8s-master flask]# cat demo.yaml 
apiVersion: v1
kind: Namespace
metadata:
  name: demo
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo
  namespace: demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      imagePullSecrets:
      - name: harbor
      containers:
      - name: demo
        image: registry.kubernetes-devops.cn/library/httpd:latest
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: demo
  namespace: demo
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
  selector:
    app: demo
    
# 这里更换一个镜像，然后我们提交以下代码并在ArgoCD再次 SYNC一下
[root@k8s-master flask]# git add .
[root@k8s-master flask]# git commit -m "fix httpd"
[master 0d963aa] fix httpd
 1 file changed, 1 insertion(+), 1 deletion(-)
[root@k8s-master flask]# git push origin master 
Username for 'http://10.0.0.10:31179': devops
Password for 'http://devops@10.0.0.10:31179': 
Counting objects: 5, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 280 bytes | 0 bytes/s, done.
Total 3 (delta 1), reused 0 (delta 0)
remote: . Processing 1 references
remote: Processed 1 references in total
To http://10.0.0.10:31179/devops/flask.git
   eb92f56..0d963aa  master -> master

# 我们在增加新服务的时候我们可以看看pod的变化
[root@k8s-master flask]# kubectl get pod -n demo --watch
NAME                    READY   STATUS    RESTARTS   AGE
demo-8645cf44c9-jf4g5   1/1     Running   0          3m20s
demo-9f6c4b7f5-5mmqp    0/1     Pending   0          0s
demo-9f6c4b7f5-5mmqp    0/1     Pending   0          0s
demo-9f6c4b7f5-5mmqp    0/1     ContainerCreating   0          0s
demo-9f6c4b7f5-5mmqp    0/1     ContainerCreating   0          0s
demo-9f6c4b7f5-5mmqp    1/1     Running             0          2s
demo-8645cf44c9-jf4g5   1/1     Terminating         0          3m28s
demo-8645cf44c9-jf4g5   1/1     Terminating         0          3m28s
demo-8645cf44c9-jf4g5   0/1     Terminating         0          3m29s
demo-8645cf44c9-jf4g5   0/1     Terminating         0          3m29s
demo-8645cf44c9-jf4g5   0/1     Terminating         0          3m29s

# 这里可以看到，更新策略是先启动一个新的然后再删除老的，这里测试一下访问

[root@k8s-master flask]# kubectl get pod,svc -n demo 
NAME                       READY   STATUS    RESTARTS   AGE
pod/demo-9f6c4b7f5-5mmqp   1/1     Running   0          95s

NAME           TYPE       CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
service/demo   NodePort   200.1.240.228   <none>        80:31086/TCP   5m1s
[root@k8s-master flask]# curl 10.0.0.10:31086
<html><body><h1>It works!</h1></body></html>
# 这里可以看到已经更新了

# 那么如果我们在这个yaml里面再增加一个pod呢？我们来实践一下，再次变更代码
[root@k8s-master flask]# cat demo.yaml 
apiVersion: v1
kind: Namespace
metadata:
  name: demo
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo
  namespace: demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      imagePullSecrets:
      - name: harbor
      containers:
      - name: demo
        image: registry.kubernetes-devops.cn/library/httpd:latest
        ports:
        - containerPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: demos
  namespace: demo
spec:
  replicas: 1
  selector:
    matchLabels:
      app: demos
  template:
    metadata:
      labels:
        app: demos
    spec:
      imagePullSecrets:
      - name: harbor
      containers:
      - name: demos
        image: registry.kubernetes-devops.cn/library/nginx:alpine
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: demo
  namespace: demo
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
  selector:
    app: demo
---
apiVersion: v1
kind: Service
metadata:
  name: demos
  namespace: demo
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
  selector:
    app: demos

# 提交代码
[root@k8s-master flask]# git add .
[root@k8s-master flask]# git commit -m "add service"
[master 16ccff1] add service
 1 file changed, 38 insertions(+)
[root@k8s-master flask]# git push origin master 
Username for 'http://10.0.0.10:31179': devops
Password for 'http://devops@10.0.0.10:31179': 
Counting objects: 5, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (3/3), 318 bytes | 0 bytes/s, done.
Total 3 (delta 1), reused 0 (delta 0)
remote: . Processing 1 references
remote: Processed 1 references in total
To http://10.0.0.10:31179/devops/flask.git
   0d963aa..16ccff1  master -> master

# 在ArgoCD内再次SYNC，然后观察容器的更新
[root@k8s-master flask]# kubectl get pod -n demo --watch
NAME                   READY   STATUS    RESTARTS   AGE
demo-9f6c4b7f5-5mmqp   1/1     Running   0          6m43s
demos-7d56f6966c-brsvt   0/1     Pending   0          0s
demos-7d56f6966c-brsvt   0/1     Pending   0          0s
demos-7d56f6966c-brsvt   0/1     ContainerCreating   0          0s
demos-7d56f6966c-brsvt   0/1     ContainerCreating   0          0s
demos-7d56f6966c-brsvt   1/1     Running             0          1s