Setting up container auto-healing with Docker involves two main steps, monitoring your Docker containers and then automating the process of restarting them if they fail. Here’s a basic guide on how:
1. Monitoring Docker Containers:
Docker has a built-in mechanism for monitoring containers and restart them if they fail. This is controlled by the —restart flag when you run a new container. You can set this flag to several different values:- no – This is the default value, Docker will not attempt to restart the container if it fails.
- on-failure – Docker will only restart your container if it exits with a non-zero exit status.
- unless-stopped – Docker will always restart the container regardless of exit status unless it has been manually stopped.
- always – Docker will always restart a container regardless of exit status.
1. Automating Recovery:
If you wish to have more dynamic control over your Docker containers than the built-in restart policy offers or if you want to scale out the recovery process across a cluster of containers, then you’ll need to look at Docker Swarm or a third-party orchestrator such as Kubernetes. Please note, Docker itself can’t automatically repair a container if it starts failing. It can only restart the same, possibly broken, container image. If you need to automatically deploy new container images, handle more complex failover scenarios, or manage multi-container applications, you should look into orchestration solutions which handle these scenarios. With Docker Swarm or Kubernetes, you can set up full service health checks and even automate the rollout of new container versions.Remember, the right method for handling container recovery depends entirely on your individual application and business requirements. It’s advisable to understand the capabilities and limitations of Docker’s built-in tools and consider third-party options as needed.
