This commit changes the Dockerfile ot use the multi-stage build and help
to get an automated build on Docker.
The idea of the multi-stage build is to use the already stable Debian
distribution channel to provide up-to-date versions of ZeroTier.
The benefit is that it would be possible to automate the image build,
either on Docker Hub, Travis or taking advantage of the [docker-library/official-images] infrastructure.
This changes follows the best-practices suggested by
[docker-library/official-images], such as using a High Availability GPG
keyserver, providing a default CMD, allowing "bash" on `docker run` and
others.
Given that both the builder `debian:stretch` and `alpine:latest` are
official messages and have [manifests], this means that this Dockerfile
is also multi-platform. This means that this same Dockerfile will
pick-up the correct Debian package according to the architecture of the
running system during build.
With this changes we could try to promote the image to be parte of
[docker-library/official-images], and take advantage of automated
publishing of multi-architecture images. Others would be able to use
`docker run zerotier` and download the latest version appropriate to
their system.
Related to #682
[docker-library/official-images]: https://github.com/docker-library/official-images
[manifests]: https://blog.docker.com/2017/09/docker-official-images-now-multi-platform/
* Fixed a bug that caused exits to take a long time on Mac due to huge numbers of redundant attempts to delete managed routes.
* Fixed a socket limit problem on Windows that caused the ZeroTier service to run out of sockets, causing the UI and CLI to be unable to access the API.
* Fixed a threading bug in the ZeroTier Core, albeit one that never manifested on the regular ZeroTier One service/client.
* Fixed a bug that could cause the service to crash if an authorized local client accessed an invalid URL via the control API. (Not exploitable since you needed admin access anyway.)
when building with `ZT_DEBUG=1` this hint produces a warning:
> node/Packet.cpp:335:43: error: 'register' storage class specifier is deprecated and incompatible with C++17 [-Werror,-Wdeprecated-register]
See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4340
