Fix kubectl exec command: use -- separator and grep instead of Select-String

README.md

@@ -1 +1,20 @@
-# thomas.github.com
+# thomas.github.com
+
+## Kubernetes Debugging
+
+### Checking environment variables in a pod
+
+To inspect environment variables (e.g., database/datasource settings) in a running container, use the correct `kubectl exec` syntax with `--` to separate the pod name from the command:
+
+```bash
+kubectl exec -n contentautomation contentautomation-appmanager-557994955f-5x254 -- printenv | grep -E "DB|POSTGRES|JDBC|SPRING_DATASOURCE"
+```
+
+**Common mistakes to avoid:**
+
+| Incorrect | Correct |
+|-----------|---------|
+| `kubectl exec <pod> - <command>` (single dash) | `kubectl exec <pod> -- <command>` (double dash) |
+| `Select-String` (PowerShell only) | `grep -E` (Linux/bash) |
+
+The single `-` causes the error `exec: "-": executable file not found in $PATH` because kubectl tries to execute `-` as a command inside the container instead of treating it as the argument separator.