Docker interactive exec bash does not show container's filesystem

Docker Engine General
1

when I enter a container it doesn’t actually show the container’s filesystem but my regular host-filesystem

e.g.

docker exec -it cranky_mccarthy bash
root@c394feaf6fc8:/# cat /etc/lsb-release
DISTRIB_ID=Debian
DISTRIB_RELEASE=7
DISTRIB_CODENAME=
DISTRIB_DESCRIPTION=
root@c394feaf6fc8:/# exit
root@host:/ cat /etc/lsb-release
DISTRIB_ID=Debian
DISTRIB_RELEASE=7
DISTRIB_CODENAME=
DISTRIB_DESCRIPTION=

whereas the container is actually ubuntu derived

Is this intended behaviour for the new ‘exec’ functionality?

2

This seems off to me. You should report it on the Github Issues.

3

This is not how it works for me, can you please do a totally explict test including your docker run and its /etc/lsb

root@382cc7045cef:/etc# more lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.1 LTS"
root@382cc7045cef:/etc# exit
[root@t440s docker]# more /etc/
Display all 258 possibilities? (y or n)
[root@t440s docker]# more /etc/redhat-release 
Fedora release 20 (Heisenbug)
[root@t440s docker]# ls /etc/lsb*
ls: cannot access /etc/lsb*: No such file or directory

(ubuntu container running on a fedora box)

4 
docker run -it ubuntu bash
root@a44551c973c4:/# cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.1 LTS"
[^P^Q]
docker exec -ti a44551c973c4 bash
dircolors: no SHELL environment variable, and no shell type option given
root@a44551c973c4:/# cat /etc/lsb-release
DISTRIB_ID=Debian
DISTRIB_RELEASE=7
DISTRIB_CODENAME=
DISTRIB_DESCRIPTION=

And version info:

aptitude show lxc-docker
Package: lxc-docker
New: yes
State: installed
Automatically installed: no
Version: 1.3.1
Priority: extra
Section: default
Maintainer: support@docker.com
Architecture: amd64
Uncompressed Size: 0
Depends: lxc-docker-1.3.1

Hope this helps

/update, the warning about dircolors seems unrelated, running the ‘cat /etc/lsb-release’ gives the unexpected output as well:

docker exec  a44551c973c4 cat /etc/lsb-release
DISTRIB_ID=Debian
DISTRIB_RELEASE=7
DISTRIB_CODENAME=
DISTRIB_DESCRIPTION=
5

Ok sorry for this, install documents clearly state that kernel 3.14 or newer should be used. Debian 7.7 by default is on 3.2. Installed new kernel and it’s working now.

Though a runtime warning of some kind would’ve been very helpful.

6

WOW! awesome! thats a really useful thing to know about.

I’ve added a link to this in https://github.com/docker/docker/pull/7681

7

As a bug/issue reporter, just happy to see you guys are really using this kind of information and providing nice feedback.

8

I experienced the same it seems, but I’m on 3.2.0: https://github.com/docker/docker/issues/8976