markdown 在Docker for Mac Moby VM中获取Shell

Posted 2021-05-06

## 2018 Update: Easiest option is Justin's repo and image

Just run this from your Mac terminal and it'll drop you in a container with full permissions on the Moby VM. **This also works for Docker for Windows for getting in Moby Linux VM** (doesn't work for Windows Containers).

`docker run -it --rm --privileged --pid=host justincormack/nsenter1`

more info: https://github.com/justincormack/nsenter1

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## Option 1: use Screen (not as easy as nsenter)

Note this isn't a list of commands to run in order. The first one gets you in the VM (hit return twice 
to see a prompt). Then other commands are for managing that connection. Not a great CLI expirence but gets
the job done. Using the ctrl- options prevents garbled text on reconnect.

connect to tty on Docker for Mac VM

`screen ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty`

disconnect that session but leave it open in background

`Ctrl-a d`

list that session that's still running in background

`screen -ls`

reconnect to that session (don't open a new one, that won't work and 2nd tty will give you garbled screen)

`screen -r`

kill this session (window) and exit

`Ctrl-a k`

## Option 2 (easier): Use nsenter in priviledged container

`docker run -it --privileged --pid=host debian nsenter -t 1 -m -u -n -i sh`

Phil Estes (Docker Maintainer) says:

> it’s running a container (using the debian image..nothing special about it other than it apparently has 
`nsenter` installed), with pid=host (so you are in the process space of the mini VM running Docker4Mac), 
and then nsenter says “whatever is pid 1, use that as context, and enter all the namespaces of that, and run a shell there"

### Or even easier, from Justin Cormack (Docker Maintainer)

`docker run -it --rm --privileged --pid=host justincormack/nsenter1`

Justin Says: 

> Personally I mostly use screen, but then I also use the above too. That's my minimal nsenter image.