I've been trying to get to grips with Docker over the last few days, and as learning
exercise I've been trying to build a chain of images from scratch, however I've
run into some problems and I hope someone can put me on the right track.
I working in a VM running Fedora 21 Beta Server, fully up to date. My Docker version is
docker-io 1.3.2-2.fc21.
The steps I've taken are:
1) Downloaded Fedora-Docker-Base-20141029-21_Beta.x86_64.tar.gz to a directory called
fedora and created a file in that directory called Dockerfile with only three lines:
FROM scratch
MAINTAINER Keith Sharp <kms(a)passback.co.uk>
ADD Fedora-Docker-Base-20141029-21_Beta.x86_64.tar.gz /
2) Used the docker command to build a new image:
$ sudo docker build -t passback/fedora:21beta .
Sending build context to Docker daemon 83.58 MB
Sending build context to Docker daemon
Step 0 : FROM scratch
Pulling repository scratch
511136ea3c5a: Pulling image (latest) from scratch, endpoint:
https://registry-1.511136ea3c5a: Download complete
Status: Downloaded newer image for scratch:latest
---> 511136ea3c5a
Step 1 : MAINTAINER Keith Sharp <kms(a)passback.co.uk>
---> Running in 9091a442001f
---> bbcce511a8de
Removing intermediate container 9091a442001f
Step 2 : ADD Fedora-Docker-Base-20141029-21_Beta.x86_64.tar.gz /
---> 7058f928f119
Removing intermediate container de568a0cb7f8
Successfully built 7058f928f119
3) So far so good, the images show up as expected:
$ sudo docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL
SIZE
passback/fedora 21beta 7058f928f119 2 minutes ago 225.7 MB
scratch latest 511136ea3c5a 17 months ago 0 B
4) However, when I try to launch my new image I hit a problem:
$ sudo docker run --rm -ti passback/fedora:21beta /bin/sh
2014/11/26 14:15:10 Error response from daemon: Cannot start container
19fad5c0c8e1a11784b616d17d632c9a8978bdfed2fb2aca75252e28619ef5c1: exec:
"/bin/sh": stat /bin/sh: no such file or directory
5) I had thought it was because I was missing a CMD or ENTRYPOINT instruction so I tried
creating a new image based on this Dockerfile:
FROM passback/fedora:21beta
MAINTAINER Keith Sharp <kms(a)passback.co.uk>
CMD ["/bin/bash"]
6) The build works, but when I try to run I get the same error:
$ sudo docker run --rm -ti passback/test
2014/11/26 14:19:24 Error response from daemon: Cannot start container
1a20d7ceade9f4bc2d729ca081c10d849fe941e748de804fb1ad75abbf4d4941: exec:
"/bin/bash": stat /bin/bash: no such file or directory
I'm sure I'm missing something simple, but no amount of searching is helping.
Could someone point me in the right direction?
Thanks,
Keith.