feat: add troubleshoot page ✨

  - add DNS issues entry

gefyra/versioned_docs/version-2.x/troubleshoot.md

@@ -0,0 +1,19 @@
+---
+title: Troubleshooting
+sidebar_position: 11
+---
+# Troubleshooting
+
+## DNS Issues
+Sometimes you might have the following situation:
+1. An arbitrary cluster with gefyra installed
+2. Some application (for example a database) running in a namespace
+3. Another application (running in a different namespace) consuming the first application via e.g. an API
+
+You then most likely use a cluster service url for communication.  
+Something like `my-application-service.my-namespace.svc.cluster.local`.
+
+Now, sometimes when you execute `gefyra run` for your second application resolving the DNS entry for the first application fails.
+Most of the time this is due to the service being headless. 
+
+We recommend checking your services and cluster communication again.