How to Connect PostgresSQL Pod to Ruby on Rails Pod in Kubernetes

Steps to identify the possible issue:

1. Make sure that communication between different areas (namespaces) is allowed. Normally, services can only be reached within their area. Reference: Click Here

2. Check if the name “myteam-demodb” can be found within the Rails pod using tools like nslookup or dig.

3. Test the connection to the PostgreSQL service directly using its ClusterIP within the Rails application to narrow down the problem.

4. Confirm that the Network Policies permit traffic between different areas.

5. Verify that the hostname in your database.yml file (host: myteam-demodb) matches the service name.

6. Check if the IP address of the “myteam-demodb” service matches the PostgreSQL pod (use kubectl describe service myteam-demodb).

7. Ensure the kube-dns service is working properly by checking its status with kubectl get service kube-dns -n kube-system.

8. Investigate logs within the Rails pod and events related to the PostgreSQL pod (kubectl get events -n jx-staging).

9. Look for any network policies or security groups that might be blocking communication between different areas.

10. Use tools like kubectl exec for debugging within the pod.