GitLab (via Docker) on a QNAP NAS with ARM CPU ("exec format error") - docker

Question

I just bought a QNAP TS-832X NAS (Firmware: 4.3.4.0695 Build 20180830).
This machine comes with an ARM CPU (Annapurna Labs Alpine AL324 Quad-core ARM Cortex-A57 CPU # 1.70GHz).
I bought it only to install GitLab on it, but the official image doesn't seem to work.
When I try to run the image it fails.
[~] # docker run -d --name gitlab-server --hostname build1 -p 10080:10080 -p 10022:22 -p 10443:443 -v /share/GitLab/config:/etc/gitlab -v /share/GitLab/logs:/var/log/gitlab -v /share/GitLab/data:/var/opt/gitlab --restart always gitlab/gitlab-ce:latest
[~] # docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a176158729ad gitlab/gitlab-ce:latest "/assets/wrapper" 5 seconds ago Restarting (1) 1 second ago gitlab-server
[~] # docker logs a1
standard_init_linux.go:185: exec user process caused "exec format error"
standard_init_linux.go:185: exec user process caused "exec format error"
standard_init_linux.go:185: exec user process caused "exec format error"
standard_init_linux.go:185: exec user process caused "exec format error"
standard_init_linux.go:185: exec user process caused "exec format error"
standard_init_linux.go:185: exec user process caused "exec format error"
standard_init_linux.go:185: exec user process caused "exec format error"
After googling I figured it might be caused by the host architecture, so I tried running ulm0/gitlab, but with the same result.
I also tried other images with "ARM" in their tags like arm64v8/ubuntu. This one didn't even give any logs.
[~] # docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2b2b68bc912c arm64v8/ubuntu:latest "/bin/bash" 7 seconds ago Restarting (0) 1 second ago ubuntu-arm
a176158729ad gitlab/gitlab-ce:latest "/assets/wrapper" 2 hours ago Restarting (1) 51 seconds ago gitlab-server
[~] # docker logs 2b
[~] #
uname -a
Linux build1 4.2.8 #2 SMP Thu Aug 30 07:33:01 CST 2018 aarch64 GNU/Linux
docker version
Client:
Version: 17.09.1-ce
API version: 1.32
Go version: go1.8.3
Git commit: a9fd393
Built: Fri Aug 3 04:31:20 2018
OS/Arch: linux/arm64
Server:
Version: 17.09.1-ce
API version: 1.32 (minimum version 1.12)
Go version: go1.8.3
Git commit: a9fd393
Built: Fri Aug 3 04:31:20 2018
OS/Arch: linux/arm64
Experimental: false

Answer 1

Sorry to hear about your problem, unfortunately I don't believe there is any official GitLab Docker image for ARM devices.
From personal experience I've found that most developers will make a Docker image for Intel devices but not work on ARM Devices.
This topic has been discussed on the QNAP Forums already:
My QNAP is Intel based, so I can't corroborate your results, but quoting a few sentences from a page about docker on Raspberry Pi:
"Docker-based apps you use have to be packaged specifically for ARM architecture! Docker-based apps packaged for x86/x64 will not work and will result in an error such as:
FATA[0003] Error response from daemon: Cannot start container 0f0fa3f8e510e53908e6a459e817d600b9649e621e7dede974d6a65761ad39e5: exec format error
Keep this in mind when searching for apps on the Docker Hub - the source for Docker apps/images. If you see the keyword RPI or ARM in the heading or description, this app can usually be used for the Raspberry Pi."
The TS-831X has a "AnnapurnaLabs, an Amazon company Alpine AL-314 Quad-core 1.7 GHz Cortex-A15 processor" CPU, which is an ARM architecture much like the Raspberry Pi..
So, I suspect you may be limited in what Docker images you have access to and unless an official/canonical maintainer of an app also makes an ARM build, you may be stuck with either rolling your own or trusting a 3rd party hobbyist to do so...
I hate to say this but I'd say you should have picked up an Intel one instead.
I have a QNAP TS-251+ (Intel based) with 8GB RAM and 2x8TB in a RAID Configuration and this works perfectly for my Gitlab instance, in addition to running PLEX and using it as a Webserver as well.
I would also suggest when you do finally get it up and running to map the volumes to directories that are easy to access so you can make configuration changes easily.