xcjs

Of course!

The Docker client communicates over a UNIX socket. If you mount that socket in a container with a Docker client, it can communicate with the host's Docker instance.

It's entirely optional.

There's a container web UI called Portainer, but I've never used it. It may be what you're looking for.

I also use a container called Watchtower to automatically update my services. Granted there's some risk there, but I wrote a script for backup snapshots in case I need to revert, and Docker makes that easy with image tags.

There's another container called Autoheal that will restart containers with failed healthchecks. (Not every container has a built in healthcheck, but they're easy to add with a custom Dockerfile or a docker-compose.)

It's really not! I migrated rapidly from orchestrating services with Vagrant and virtual machines to Docker just because of how much more efficient it is.

Granted, it's a different tool to learn and takes time, but I feel like the tradeoff was well worth it in my case.

I also further orchestrate my containers using Ansible, but that's not entirely necessary for everyone.

You can tinker in the image in a variety of ways, but make sure to preserve your state outside the container in some way:

1. Extend the image you want to use with a custom Dockerfile
2. Execute an interactive shell session, for example docker exec -it containerName /bin/bash
3. Replace or expose filesystem resources using host or volume mounts.

Yes, you can set a variety of resources constraints, including but not limited to processor and memory utilization.

There's no reason to "freeze" a container, but if your state is in a host or volume mount, destroy the container, migrate your data, and resume it with a run command or docker-compose file. Different terminology and concept, but same result.

It may be worth it if you want to free up overhead used by virtual machines on your host, store your state more centrally, and/or represent your infrastructure as a docker-compose file or set of docker-compose files.