Monitor Docker Containers on Coolify

Coolify is a deployment platform. It builds your application, starts the container, and points Traefik at it. What it does not do is tell you at 03:00 that the container has been restart-looping for twenty minutes, that a certificate expires on Thursday, or that a nightly backup job stopped reporting.

Maintenant fills that gap, and it deploys the same way everything else on your Coolify server does.

Install as a Coolify resource

In your Coolify project, add a new resource of type Docker Compose and paste:

services:
  maintenant:
    image: ghcr.io/kolapsis/maintenant:latest
    ports:
      - "8080:8080"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - /proc:/host/proc:ro
      - maintenant-data:/data
    environment:
      MAINTENANT_ADDR: "0.0.0.0:8080"
      MAINTENANT_DB: "/data/maintenant.db"
    restart: unless-stopped
volumes:
  maintenant-data:

Assign a domain in Coolify and its proxy — Traefik by default, Caddy if you switched — will terminate TLS and route to port 8080 for you.

One thing to decide before you expose it: Maintenant ships no authentication of its own, by design. On Coolify the simplest answer is Traefik basic-auth middleware, or an existing SSO proxy if you already run one. Do not put it on a public domain unprotected.

What you get on a Coolify host

Because Maintenant reads the socket rather than a Coolify API, it sees the whole host, not just the resources Coolify manages:

• every container’s state, health check, restart loop and logs — your applications, Coolify’s own services, Traefik, and the databases Coolify provisioned;
• HTTP and TCP checks on the domains you publish, so an application that returns 502 behind a healthy container still pages you;
• SSL/TLS expiry, auto-detected from those endpoints — useful when a certificate stops renewing quietly;
• cron and background job deadlines through heartbeat URLs;
• per-container CPU, memory, network and disk metrics;
• image updates, by comparing OCI registry digests against what you are running.

That last one pairs well with Coolify: it tells you which of your deployed images have moved upstream, before you decide to redeploy.

Caveats worth knowing

• One host, one instance. If you run Coolify across several servers, install Maintenant once and enroll the others with an agent. That is a Personal or Pro capability; Community covers the machine it runs on.
• Coolify restarts things. A redeploy is a container replacement, which Maintenant reports as a restart. Nothing is wrong; adjust the restart-loop threshold if your deploy cadence is high.
• Not an APM. It watches containers and endpoints, not your application’s internals.

Start with the free Community edition on the Coolify server you already have. It takes about 30 seconds, and nothing about your existing deployments changes.