Hacker News Reader

Comment by thecolorblue | Hacker News Reader

Is this docker for BSD or is there more going on here?

The technologies upon which this is based have been part of FreeBSD long before Docker was even conceived. This appears to be a new management tool for existing functionality, along with a praxis for use.

The technologies that Docker was based on had also been part of linux for a long time beforehand. Docker was simply a new management tool for handling them.

Both correct, adding some concrete dates and names for the technologies:

FreeBSD Jails were added in FreeBSD 4 which was released in 2000

Docker (on Linux) is based on Linux CGroups which were added in 2007

Initial release of docker in March 2013

Initial support for Docker based on jails added to FreeBSD in July 2015

Docker for FreeBSD is over a year out of date and not production ready. I tried to use it for some things and it does work, but doesn't support any of the newer APIs in newer versions of docker compose and other orchestration tools.

I really wish the Docker team would have made FreeBSD a first-class citizen, considering the native zfs support in FreeBSD. Currently the only thing Docker runs on natively is Linux. Even with the newest MacOS/Win variants, it still running in a hypervisor.

Docker runs natively on Windows as well as Linux, with no hypervisor. There is a Solaris port being worked on (unless it got cancelled). We would love an upstream FreeBSD port, I have talked to a few people who are interested in working on it. The ZFS side should be fine as there is already support, and the old port should be useful as a basis.

Containers use the Linux kernel. How does a Linux container run native on Windows? Are the entry points mapped? How does Windows enable shared read between containers? With Linux it is the dir path and then inodes. How does Windows pull this off? How does SElinux work?

What is exposed inside Windows?

Windows containers use the Windows kernel. Windows does not have SELinux so of course that is not supported. It runs Windows program not Linux programs, so there is no mapping of entry points. There is lots of docs from Microsoft eg https://docs.microsoft.com/en-us/virtualization/windowsconta...

What's MacOS's version of LXC? Windows Server Containers look like a plausible foundation, but really new.

Mac OS X has an hypervisor framework, which is also used by Docker

https://github.com/docker/hyperkit

https://developer.apple.com/reference/hypervisor

Also there is App Sandbox for writing safer applications, but it requires programming explicitly against it.

https://developer.apple.com/library/content/documentation/Se...

But a hypervisor is a full VM. LXC, and Windows containers provide that funky process level virtualization.

I guess the point i'm trying to make, there will be no "native" docker for MacOS. You'll always (or for the foreseeable future) have to start a linux VM (mabye windows?!?) to host the processes.

Windows containers are based on Hyper-V.

As for Mac OS, I use it for Cocoa and iOS development, so no experience with containers as such.

Nah, MS added a lightweight version with no hyper-v

https://docs.microsoft.com/en-us/virtualization/windowsconta...

Have to look it better then, thanks.

Reply on news.ycombinator.com