Several SidecarGateway CRs point to the same Pod

As described in CR SidecarGateway, the podSelector selects the Pods to which the CustomResource SidecarGateway should be applied.

Two different SidecarGateway CRs might point to the same Pod. That is an invalid configuration and could be detected as follows:

List the SidecarGateway CustomResources

Example

kubectl get sidecargateways.microgateway.airlock.com  
NAME        STATUS    AGE 
webapp      Active    140m 
webapp2     Error     21m

The status Error indicates that something is wrong.
Use kubectl describe sidecargateways.microgateway.airlock.com to inspect the status.

Example

kubectl describe sidecargateways.microgateway.airlock.com webapp2
...
... 
Status: 
  Conditions: 
    Last Transition Time:  2022-09-13T14:55:26Z 
    Status:                True 
    Type:                  ConfigReferencesLoaded 
    Last Transition Time:  2022-09-13T14:55:26Z 
    Message:               The Pod 'webapp-84b785f954-r49wt' is already owned by the SidecarGateway 'webapp' 
    Reason:                PodAlreadyOwned 
    Status:                False 
    Type:                  PodsSelected 
    Last Transition Time:  2022-09-13T14:55:26Z 
    Status:                True 
    Type:                  EnvoyConfigSynced 
  Pods: 
    Envoy Config:  webapp-84b785f954-r49wt 
    Name:          webapp-84b785f954-r49wt 
  Status:          Error 
Events:            <none>

The Status.Conditions.Message field contains the reason for the issue and says, that already another SidecarGateway is configuring the same Pod.
Adjust the existing SidecarGateway CustomResources which point to the same Pod.
The status of the SidecarGateway CRs has changed to Active.