How do you monitor status of multiple docker containers? My home server has about 15 distinct services running, each represented by a Docker container. Depending on how the developers implemented the Dockerfile, some services have health checks, but most do not.

At the moment, I do not have a way to make sure these services remain healthy and running. I do have the restart: always setting set, but worst case this just means Docker endlessly restarts a server if it fails to start or crashes on startup for whatever reason. Or maybe a docker pull caused an issue during an update. There could be many reasons why these services do not start, or stop running during the day.

What I'd like is to know when they go down. Maybe an email that notifies me, so I can go fix the issue, instead of only finding out about the issue when a family member notifies me or when I try to use that service.

Is there a reasonable way to monitor multiple Docker containers in this way? Do I have to hand-write a bunch of scripts that do ps to check for process up time or something? Preferably an out-of-the-box solution would be great. Note I use Docker Compose for everything, and I only have 1 physical machine where I run these services, so I don't need to worry about complex setups.
Note: answer based only on docs, I didn't play with docker much.

If you choose scripting you could pick a higher layer than just ps, based on either:


the docker-compose events CLI:



Usage: events [options] [SERVICE...]

Options:
    --json      Output events as a stream of json objects

  
  Stream container events for every container in the project.



the docker events CLI:



  Description 
  
  Get real time events from the server


You'd be looking for the die event of the container(from Extended description):


  Use docker events to get real-time events from the server. These
  events differ per Docker object type.
  
  Object types
  
  CONTAINERS
  
  
  die
  


The event appears to be generated regardless of the restart policy (from Docker Events Explained):



But you're right, there's a ton of monitoring tools out there, I also suspect some already do what you're seeking.

Just aimlessly wandering through those links I got to Implementing Docker event monitoring from scratch:


  What else? I can create alerts on them. The next time any of my
  containers decide to puke and die, I can get an SMS message about
  their doomed state.