Standardize and fix (Auto-)DNS for Linux, Windows 7/8/10 and MacOS (Native and Docker Toolbox)

# Auto-DNS standardization and fixes

This ticket will address various Auto-DNS related issues for all operating systems and all Docker versions.

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## Idea

I will introduce a second DNS container which will always be able to point to whatever IP the Devilbox is running. A second container is necessary to be independent of the internal DNS name resolution. This one can then also be bound to a computers external interface to be shared within the corporate LAN.

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## Goal

* Automatically have access to all projects (via Auto-DNS) from
- your local computer (native or Docker Toolbox)
- your local LAN
- other computers on the LAN
- Android mobiles on the LAN
- iPhones on the LAN

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## Open tasks

* [ ] Fix Auto-DNS for Docker Toolbox
- [ ] Introduce dedicated `autodns` container
- [ ] Update documentation
* [ ] Documentation: Setup Devilbox in a LAN
- [ ] Lan computer: how to use Devilbox remote DNS server
- [ ] Android: how use Devilbox remote DNS server
- [ ] iPhone: how to use Devilbox remote DNS server
* [ ] Documentation: Auto-DNS for Linux (various methods: nm, systemd, etc)

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## Note

I have closed all related tickets and linked them here. As soon as the first pull request is ready I will add it here including new instructions.

## Comments, suggestions, wishes

Any ideas, comments or feature requests regarding (Auto-)DNS are welcome and I will try to include them in the new setup. Feel free to add anything you wish to see for that.

## Pull request

* https://github.com/cytopia/devilbox/pull/411