Antrea Container Cluster Status is Down

If the status of the Antrea container cluster is down, follow the steps in this documentation either to determine the cause of this issue and recover from it, or collect the support bundle.

Problem

The cluster control plane node is down. The Antrea container cluster is disconnected from the Central Control Plane (CCP).

Cause

In the NSX Manager UI, navigate to System > Fabric > Nodes > Container Clusters > Antrea. If required, filter the list of clusters on the Antrea page with the External ID field.

Click the Status column of the problematic cluster. If all the components are down, the possible causes are:

The Kubernetes cluster is deleted.
Network connectivity issue with the CCP.
The adapters are crashed or deleted for some reason.
The client certificate of the adapters is incorrect.
The version of the adapters is incompatible with the CCP.

If only the Central Control Plane Adapter is down, the CCP Adapter might have crashed.

Solution

If the Kubernetes cluster is deleted, clean up the leftover registration and inventory data in NSX. See Clean up Antrea Data from NSX.
Get the kubectl and kubeconfig access for the container cluster. Use kubectl to retrieve the node name on which the interworking pod is running. Start an SSH session to the node and use the curl or nc command to connect to every NSX Manager IP on ports 1234 and 1235. If the connection cannot be established, the cause is network connectivity issue with the CCP.
Example of the curl command:
Ensure that you replace NSX-Manager-IP with the IP address of NSX Manager in your environment.
```
curl -v NSX-Manager-IP:1235

Trying NSX-Manager-IP... 
Connected to NSX-Manager-IP (NSX-Manager-IP) port 1235 (#0) 
... 
Empty reply from server 
Connection #0 to host NSX-Manager-IP left intact 
curl: (52) Empty reply from server
```
Example of the nc command:
```
nc -v NSX-Manager-IP 1235 < /dev/null

Ncat: Version 7.50 (https://nmap.org/ncat)
Ncat: Connected to NSX-Manager-IP:1235.
Ncat: 0 bytes sent, 0 bytes received in 0.37 seconds.
```
Use kubectl to check whether all containers of the interworking pod in the vmware-system-antrea namespace are up.
If any container is down, use kubectl to get logs of the crashed containers and check the error message. This step can help you identify failure due to any of these reasons:
- The adapters are crashed or deleted for some reason.
- CCP Adapter is crashed.
Example of the kubectl command for getting the interworking pod:
```
kubectl get pod -o wide -l app=antrea-interworking -n vmware-system-antrea
```
Note down the interworking pod name.

Example of the kubectl command for getting the detailed state of the interworking pod:

Ensure that you replace pod-name with the actual pod name.
```
kubectl get pod -o yaml pod-name -n vmware-system-antrea
```
Example of the kubectl command for getting container logs:

Ensure that you replace pod-name with the actual pod name.
```
kubectl logs pod-name -c mp-adapter -n vmware-system-antrea > mp-adapter.log
kubectl logs pod-name -c ccp-adapter -n vmware-system-antrea > ccp-adapter.log
kubectl logs pod-name -c tn-proxy -n vmware-system-antrea > tn-proxy.log
kubectl logs pod-name -c election-runner -n vmware-system-antrea > election-runner.log
```
If the vmware-system-antrea namespace is missing or the interworking pod is missing, the adapters might have been deleted from the Kubernetes cluster without running the deregistration steps. You can clean up the leftover registration data and inventory from the system, and then register the Kubernetes cluster again. The cluster ID will be different after reregistering the cluster. If there is any Antrea policy applied to the cluster, you must apply the policy again after reregistering the cluster.

For instructions about cleaning up the leftover registration data, see Clean up Antrea Data from NSX.

For instructions about registering an Antrea container cluster to NSX, see Registering an Antrea Container Cluster to NSX-T Data Center.
Use kubectl to get nsx-proxy container logs from the interworking pod, and check the error messages.
This step can help you identify failure due to any of these reasons:
- The client certificate of the adapters is incorrect.
- The version of the adapters is incompatible with the CCP.
For example commands, see step 3.
If the Management Plane Adapter is up, use the support bundle feature in NSX to collect log files for the container cluster.

For more information, see Collect Support Bundles for an Antrea Container Cluster.