web_based_terminal.md

Web-based Terminal

Since v2.4, Argo CD has a web-based terminal that allows you to get a shell inside a running pod just like you would with kubectl exec. It's basically SSH from your browser, full ANSI color support and all! However, for security this feature is disabled by default.

This is a powerful privilege. It allows the user to run arbitrary code on any Pod managed by an Application for which they have the exec/create privilege. If the Pod mounts a ServiceAccount token (which is the default behavior of Kubernetes), then the user effectively has the same privileges as that ServiceAccount.

Enabling the terminal

1. In the argocd-cm ConfigMap, set the exec.enabled key to "true". This enables the exec feature in Argo CD.

   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: argocd-cm
     namespace: <namespace>  # Replace <namespace> with your actual namespace
   data:
     exec.enabled: "true"
   

2. Patch the argocd-server Role (if using namespaced Argo) or ClusterRole (if using clustered Argo) to allow argocd-server to exec into pods

    - apiGroups:
      - ""
      resources:
      - pods/exec
      verbs:
      - create
   

   If you'd like to perform the patch imperatively, you can use the following command:

   • For namespaced Argo

     kubectl patch role <argocd-server-role-name> -n argocd - type='json' -p='[{"op": "add", "path": "/rules/-", "value": {"apiGroups": ["*"], "resources": ["pods/exec"], "verbs": ["create"]}}]'
     

   • For clustered Argo

     kubectl patch clusterrole <argocd-server-clusterrole-name> - type='json' -p='[{"op": "add", "path": "/rules/-", "value": {"apiGroups": ["*"], "resources": ["pods/exec"], "verbs": ["create"]}}]'
     ```
     
     

3. Add RBAC rules to allow your users to create the exec resource i.e.

    p, role:myrole, exec, create, */*, allow 
   

   This can be added either to the argocd-cm Configmap manifest or an AppProject manifest.

   See RBAC Configuration for more info.

Changing allowed shells

By default, Argo CD attempts to execute shells in this order:

1. bash
2. sh
3. powershell
4. cmd

If none of the shells are found, the terminal session will fail. To add to or change the allowed shells, change the exec.shells key in the argocd-cm ConfigMap, separating them with commas.