What are the strategies for restarting containers in Docker and how do they work?

Docker has several container restart strategies, which are set using the --restart option when starting a container. The main ones are:

• no — the container does not restart automatically (default value).
• on-failure[:max-retries] — the container restarts only if it exits with an error (exit code != 0). You can specify a maximum number of retries.
• always — the container always restarts, regardless of the exit code.
• unless-stopped — the container always restarts, except when it was stopped manually.

For example, docker run --restart=on-failure:3 will attempt to restart the container up to 3 times on errors.

These strategies help ensure service resilience by automatically recovering containers after failures.