[FAQ Bot] NEW: Why does Agent Relay fail to connect to PostgreSQL in a local kind Kuber

_questions/ai-dev-tools-zoomcamp/03-deployment/004_2f63569378_agent-relay-postgres-kind-localhost-service-dns.md

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+---
+id: 2f63569378
+question: Why does Agent Relay fail to connect to PostgreSQL in a local kind Kubernetes
+  cluster when the DB host is set to `localhost`, and what should I change?
+sort_order: 4
+---
+
+In Kubernetes, `localhost` inside the Agent Relay pod refers to the Agent Relay container itself, not to the PostgreSQL server. So if you set the PostgreSQL host to `localhost:5432`, Agent Relay will look for PostgreSQL inside its own pod and fail.
+
+Change the configuration to use a Kubernetes `Service` hostname instead of `localhost`. For example, if you create a `Service` for PostgreSQL named `postgres`, Agent Relay should connect to `postgres:5432` (or the matching service DNS name in your manifests).
+
+Example `Service`:
+```yaml
+apiVersion: v1
+kind: Service
+metadata:
+  name: postgres
+spec:
+  selector:
+    app: postgres
+  ports:
+    - port: 5432
+      targetPort: 5432
+```
+
+Then in Agent Relay’s DB URL, use the service name:
+```text
+postgresql://<user>:<password>@postgres:5432/<database>
+```
+
+If you’re running locally with `kind` and building the Agent Relay image yourself, make sure the image is available to the cluster:
+```bash
+docker build -t agent-relay:local .
+kind load docker-image agent-relay:local
+```
+
+After applying manifests, you can verify things by checking pods/services and reviewing logs:
+```bash
+kubectl get pods
+kubectl get services
+kubectl logs deployment/agent-relay
+```
+
+This is different from Docker Compose: in Compose, container-to-container access can often use service names directly, while Kubernetes requires using Services (and their DNS) for stable cross-pod connectivity.