Monitoring Gefyra with Vigilmon

Gefyra is a developer tooling project that lets you run a local Docker container as if it were running inside your Kubernetes cluster — full network access, same DNS resolution, same service mesh membership. It's invaluable for inner-loop development: write code locally, test against real cluster services, without a kubectl cp or image rebuild cycle. But Gefyra's bridge tunnel can go stale, the operator can get stuck, and when that happens developers lose their cluster connection silently. Vigilmon lets you monitor the Gefyra operator's health endpoint and set up a heartbeat that verifies the bridge tunnel is actually routing traffic end-to-end.

What You'll Set Up

• HTTP monitor for the Gefyra operator pod readiness
• TCP probe to confirm the Gefyra proxy port is open
• Heartbeat from a dev tunnel round-trip to verify end-to-end connectivity
• Notifications for platform engineering teams who maintain shared dev clusters

Prerequisites

• Kubernetes cluster running Gefyra operator (v2.0+)
• kubectl access to the namespace where Gefyra is installed
• A free Vigilmon account

Step 1: Monitor the Gefyra Operator

Gefyra deploys an operator (gefyra-operator) that manages GefeyraBridgeRequest and connection lifecycle resources. Check that it's running:

kubectl get deploy -n gefyra
# gefyra-operator   1/1   Running

The operator pod exposes a readiness probe internally. Expose it for external monitoring:

kubectl expose deploy gefyra-operator \
  -n gefyra \
  --name gefyra-operator-health \
  --port 8080 \
  --target-port 8080 \
  --type NodePort

If port 8080 isn't exposed by the operator, check with:

kubectl describe deploy gefyra-operator -n gefyra | grep -A5 "readiness"

Then add a Vigilmon monitor:

1. Log in to vigilmon.online and click Add Monitor.
2. Set Type to HTTP / HTTPS.
3. Enter http://<node-ip>:<node-port>/healthz (or the actual readiness path).
4. Set Check interval to 2 minutes (Gefyra is a dev tool — 2-minute resolution is fine).
5. Set Expected HTTP status to 200.
6. Click Save.

Step 2: Monitor the Gefyra Stowaway Proxy Port

Gefyra uses a component called gefyra-stowaway — a WireGuard-based proxy that runs in the cluster and handles traffic between the local container and cluster services. It listens on a specific port (default: 31820/UDP for WireGuard, but also exposes a TCP status port).

Check what's exposed:

kubectl get svc -n gefyra

If gefyra-stowaway has a TCP port exposed, add a Vigilmon TCP monitor:

1. Click Add Monitor → TCP Port.
2. Enter the stowaway service IP/hostname and its TCP port.
3. Set Check interval to 2 minutes.
4. Click Save.

This catches cases where the stowaway pod is running but its service endpoint has been lost — a common failure mode after cluster upgrades.

Step 3: Verify Bridge Connectivity with a Heartbeat

The most meaningful Gefyra health check is a round-trip: a local container that uses the Gefyra bridge, makes a request to an in-cluster service, and pings Vigilmon. This verifies that the entire tunnel path (WireGuard tunnel → cluster DNS → in-cluster service) is functional.

Create a test script

#!/bin/bash
# gefyra-heartbeat.sh
# Run inside a container connected to a Gefyra bridge session

# Try to reach an in-cluster service
if curl -fsS --max-time 5 http://my-service.default.svc.cluster.local/health > /dev/null; then
  # Tunnel is working — ping Vigilmon heartbeat
  curl -fsS https://vigilmon.online/api/heartbeat/<YOUR_HEARTBEAT_ID>
  echo "Heartbeat sent: cluster reachable"
else
  echo "ERROR: cluster service unreachable via Gefyra bridge"
  exit 1
fi

Run it from a bridged container

# Start a Gefyra session bridged into the cluster
gefyra run -i curlimages/curl -n gefyra-heartbeat \
  --namespace default \
  -- sh /heartbeat.sh

Automate with a host-side cron

On the developer machine or a dedicated monitoring host with a persistent Gefyra session:

# crontab -e
*/10 * * * * gefyra run -i curlimages/curl -n hb-$(date +%%s) \
  --namespace default -- sh -c \
  'curl -fsS http://my-service.default.svc.cluster.local/health && \
   curl -fsS https://vigilmon.online/api/heartbeat/<YOUR_HEARTBEAT_ID>'

In Vigilmon:

1. Click Add Monitor → Heartbeat.
2. Set Expected interval to 10 minutes.
3. Set Grace period to 3 minutes.
4. Paste the heartbeat URL into the script.

Step 4: Monitor the Gefyra Cargo (Registry Mirror) if Used

Gefyra includes an optional component called gefyra-cargo — a local registry mirror that lets the cluster pull images from your local build. If your team uses it, add a monitor:

kubectl get svc gefyra-cargo -n gefyra
# Look for the NodePort exposing port 5000 (registry port)

Add a Vigilmon HTTP monitor at http://<node-ip>:<cargo-port>/v2/ expecting HTTP 200. A registry mirror that stops responding silently causes ErrImagePull for local development images.

Step 5: Set Up Platform Team Notifications

Gefyra is typically maintained by a platform engineering team who provides it as a shared dev cluster service. Set up team-level notifications:

1. In Vigilmon, go to Settings → Notifications.
2. Add a Slack webhook for #platform-engineering (or equivalent).
3. Assign it to all Gefyra monitors.
4. Recommended settings: Alert after 2 consecutive failures (Gefyra can have brief reconnection events during cluster node restarts).

For the heartbeat monitor, use a 15-minute notification delay — a slow heartbeat often means a developer's Gefyra session is simply idle, not that the infrastructure is broken.

What You've Built

| Monitor | Type | Signal | |---|---|---| | Operator /healthz | HTTP | Operator pod alive | | Stowaway proxy port | TCP | WireGuard gateway reachable | | Bridge heartbeat | Heartbeat | Full tunnel connectivity | | Cargo registry mirror | HTTP | Local image pull available |

Why This Matters

Gefyra failures are silent productivity killers: developers get connection refused errors, assume their local code is broken, and spend 30 minutes debugging before realizing the tunnel is down. With Vigilmon proactively alerting the platform team, bridge outages get fixed before they derail developer workflows. For shared dev clusters where multiple engineers depend on Gefyra, this monitoring setup pays for itself in reclaimed developer time with the first caught outage.