Container Service for Kubernetes:Use ACK One GitOps to deploy applications

Use the ACK One GitOps (ArgoCD) console to deploy applications

Step 1: Add a Git repository in the ArgoCD console and synchronize application configurations to specified clusters

1. Access the ArgoCD server domain name from a web browser to log on to the ArgoCD console. For more information about how to obtain the domain name of the ArgoCD server, see Log on to the GitOps system.

2. On the ArgoCD homepage, click LOGIN VIA ALIYUN.

3. Add a source Git repository.

   1. In the left-side navigation pane, choose Settings > Repositories and click + CONNECT REPO.

   2. In the panel that appears, specify the following information and click CONNECT.

      Then, the CONNECTION STATUS column of the Git repository displays Successful.

4. Create an ArgoCD application and deploy the application to the specified cluster.

   1. On the Applications page, click + NEW APP and specify the following information. The application will pull the Helm chart in the source Git repository and deploy it to the default namespace of the specified cluster.

   2. After the configuration is complete, click CREATE in the upper part of the panel.

      Then, you can view the status of the echo-server-app application on the Applications page.

   3. Click SYNC below the application to deploy the application to the specified cluster.

   4. If Healthy and Synced appear to the right of Status, the application is deployed. Click echo-server to view the details of the application, including the topology and status of the Kubernetes resources related to the application.

Step 2: Query the deployment of the application

Use the kubeconfig file to connect to the Fleet instance and run the following commands to query the deployment of the application.

1. Run the following command to query information about the clusters that are associated with the Fleet instance:

   kubectl amc get managedcluster

   Expected output:

   Name         Alias             HubAccepted
   cd****      ackpro-cluster2      true
   ce****      ackpro-cluster1      true    // The cluster in which the application is deployed.

2. Run the following command to query Deployments, Services, and pods in the default namespace. Configure the amc -m parameter to specify the cluster in which the application is deployed.

   kubectl amc get all -n default -m ce****

   Expected output:

   Run on ManagedCluster ce**** (ackpro-cluster1)
   NAME                               READY   STATUS    RESTARTS   AGE
   pod/echo-server-5cf54bdbcb-jv58k   1/1     Running   0          59m
   
   NAME                  TYPE           CLUSTER-IP        EXTERNAL-IP    PORT(S)          AGE
   service/echo-server   LoadBalancer   192.XX.XX.XX      39.XX.XX.XX   8080:31769/TCP   59m        21d
   
   NAME                          READY   UP-TO-DATE   AVAILABLE   AGE
   deployment.apps/echo-server   1/1     1            1           59m

3. Run the following command to access the public IP address of the LoadBalancer Service to query the version of the application:

   curl http://39.XX.XX.XX:8080/version

   Expected output:

   "Hello Echo Server v1.0"

   The application version is v1.0.

Step 3: Update the application

1. Change the tag of the pod image in the Git repository from v1.0 to v2.0.

   Due to the tag change in the Git repository, the ArgoCD application displays OutOfSync.

2. Click the OutOfSync icon in yellow to view the difference.

   

   The following figure shows the difference.

3. Click SYNC to initiate a synchronization task. After the task is completed, the tag of the pod image changes to v2.0.

4. Run the following command to access the Service and check the actual version:

   curl http://39.XX.XX.XX:8080/version

   Expected output:

   "Hello Echo Server v2.0"

   The output indicates that the application is updated to v2.0.

Step 4: Roll back to an application version

After the application is updated to v2.0, ArgoCD retains the original ReplicaSet for rollback.

1. Run the following command with the amc -m parameter on the Fleet instance to query the status of the resources in the specified cluster:

   kubectl amc get replicaset  -n default -m ce****

   Expected output:

   Run on ManagedCluster ce**** (ackpro-cluster1)
   NAME                     DESIRED   CURRENT   READY   AGE
   echo-server-55664c4677   1         1         1       26m    // The version is v2.0. 
   echo-server-5cf54bdbcb   0         0         0       109m   // The version is v1.0.

2. To roll back the application to v1.0, click HISTORY AND ROLLBACK on the application page to view all historical versions of the application.

3. Select v1.0 and click Rollback.

   Then, the pod image tag changes to v1.0. Due to the difference between the ArgoCD application and the source Git repository, the status of the application changes to OutOfSync. Click SYNC to initiate a synchronization task.

   Note

   ArgoCD automatically synchronizes information from the source Git repository.

Use the ArgoCD CLI to deploy applications

1. Run the following command to access ArgoCD through the ArgoCD server domain name. The ArgoCD CLI will open the web browser to complete single sign-on (SSO).

   argocd login argocd.<ackone cluster id>.<region>.alicontainer.com --sso
   Opening browser for authentication
   Performing authorization_code flow login: https://signin.aliyun.com/oauth2/v1/auth?xxx
   Authentication successful
   'root' logged in successfully
   Context 'argocd.<ackone cluster id>.<region>.alicontainer.com' update

2. Run the following command to add a source Git repository:

   argocd repo add https://github.com/AliyunContainerService/gitops-demo.git --name echo-server

   Expected output:

   Repository 'https://github.com/AliyunContainerService/gitops-demo.git' added

3. Run the following command to query Git repositories:

   argocd repo list

   Expected output:

   TYPE  NAME  REPO                                                       INSECURE  OCI    LFS    CREDS  STATUS      MESSAGE  PROJECT
   git         https://github.com/AliyunContainerService/gitops-demo.git  false     false  false  false  Successful           default

4. Run the following command to query clusters:

   argocd cluster list

   Expected output:

   SERVER                          NAME                    VERSION  STATUS   MESSAGE                                                  PROJECT
   https://10.XX.XX.XX:XX      ce****-ackpro-cluster1               Unknown  Cluster has no applications and is not being monitored.
   https://10.XX.XX.XX:XX      cd****-ackpro-cluster2               Unknown  Cluster has no applications and is not being monitored.
   https://kubernetes.default.svc  in-cluster                       Unknown  Cluster has no applications and is not being monitored.

   You can associate clusters with the Fleet instance. ACK One automatically synchronizes information about the newly associated clusters to ArgoCD.

5. Run the following command to create an application:

   argocd app create echo-server --repo https://github.com/AliyunContainerService/gitops-demo.git --path manifests/helm --revision one-demo --dest-namespace default --dest-server https://10.0.XX.XX:6443

   Expected output:

   application 'echo-server' created

6. Run the following command to pull the application configuration from the Git repository and deploy the application in the specified cluster.

   argocd app sync echo-server