Run GitLab Runner on Docker Desktop (for testing) - gitlab

I would like to run a GitLab Runner on Docker Desktop (I run a GitLab instance and a runner locally for testing purposes).
Unfornately, I could not find out how to map the Docker socket. The manual says one should use:
docker run -d --name gitlab-runner --restart always \
-v /var/run/docker.sock:/var/run/docker.sock \
-v /srv/gitlab-runner/config:/etc/gitlab-runner \
gitlab/gitlab-runner:latest
but apparently, this does not work on Windows. The information I found on StackOverflow seems to use older versions of Docker Desktop which use a Virtual Machine instead of WSL 2.
Can anybody tell me how to do the mapping on a "modern" Docker Desktop using WSL 2?

Related

Parent Docker Containers using Docker in Docker

I am working on a jenkins ssh agent for my builds
I want to have docker installed so it can run and build docker images
I currently have the following in my Dockerfile
RUN curl -fsSL get.docker.com -o /opt/get-docker.sh
RUN chmod +x /opt/get-docker.sh
RUN sh /opt/get-docker.sh
This works fine when I run docker with
docker run <image> -v /var/run/docker.sock:/var/run/docker.sock
Issue I'm having is when I run docker ps with in the container, it shows all my parent containers as well, is there a way to prevent this?
If you mount the host's /var/run/docker.sock your docker client will connect to the host's docker daemon, and so see everything that is running on the host.
To make it so your containers can run docker in a way that appears isolated from the host you should investigate Docker-in-docker.

Issue docker commands on Jenkins slave

I have a Jenkins master running on Windows Server 2016. I need to be able to run linux containers to run some automated e2e tests. For reasons I won't get into, I cannot enable hyper-v on this machine. This is preventing me from installing lcow and docker on my Jenkins master
What I've done instead is setup a Ubuntu 18.04 VM in virtualbox and installed docker there. I've configured the VM as a Jenkins slave using ssh to login as the jenkins user. I've setup and configured everything for this user to be able to run docker commands without using sudo. If I manually ssh into the server as the jenkins user I can run docker commands without an issue. Everything works the way you would expect.
I've then setup a test build to check that everything was working correctly. The problem is that when I try to run docker commands using the Execute Shell build step I'm getting a docker: not found error. From what I can tell, the build is running as the correct user. I added who -u to the build step so I could check which user the build was running as.
Here is the output from my build:
[TEST - e2e - TEST] $ /bin/sh -xe /tmp/jenkins16952572249375249520.sh
+ who -u
jenkins pts/0 2018-08-10 16:43 . 10072 (10.0.2.2)
+ docker run hello-world
/tmp/jenkins16952572249375249520.sh: 3: /tmp/jenkins16952572249375249520.sh: docker: not found
As I mentioned, the jenkins user has been added to the docker group and Docker has been added to $PATH (/snap/bin/):
jenkins#jenkins-docker-slave:~$ which docker
/snap/bin/docker
jenkins#jenkins-docker-slave:~$ $PATH
-bash:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin: No such file or directory
jenkins#jenkins-docker-slave:~$ who -u
jenkins pts/0 2018-08-10 16:43 . 10072 (10.0.2.2)
jenkins#jenkins-docker-slave:~$ cat /etc/group | grep docker
docker:x:1001:qctesting,jenkins
As you can see by this snippet I can successfully run docker commands by logging into the server as the jenkins user:
jenkins#jenkins-docker-slave:~$ docker run hello-world
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/engine/userguide/
I have also configured the path to docker in the slaves node properties as I thought it would fix my issue. As you can see I have both git and docker listed. Git commands are working just fine. It is only the docker commands that are giving me problems. I have tried both /snap/bin and /snap/bin/docker with no luck.
I am trying to build a jenkins job that will clone a git repo, spin up the containers I need using docker-compose and some build parameters I pass in at build time, and run my e2e tests against any environment (qa, staging, production, etc.). I just can't get the jenkins slave to run the docker commands. What am I missing? How can I get the slave to recognize that docker is already installed on the system and the user has the correct permissions to execute those commands.
NOTE: I am NOT trying to run docker in docker. Practically all questions/documentation I've found on running docker commands on a jenkins slave describe how to solve this issue by running the slave in a docker container and installing the docker client in the slave container. That is not what I'm trying to accomplish. I am trying to ssh from a jenkins master into a jenkins slave that already has docker installed and run docker commands on that server as the jenkins user.
I finally figured this out thanks to the answer for this question. After reading that answer I realized I had installed the wrong version of docker on Ubuntu. I removed the previous installation and installed the correct docker package using sudo curl -sSL https://get.docker.com/ | sh. I then restarted my jenkins slave and everything started working.

how to test an aws lambda function using docker

I am trying to test a simple lambda function using docker on windows.
I already have a docker lambcy/lambda image
But this line:
docker run --rm -v "$PWD":/var/task lambci/lambda
does not work on windows.
What is the appropiate way to do this?
docker run --rm -v "$PWD":/var/task lambci/lambda
The command that you running is targeting linux platform, as for windows platform maybe you can try below instead
docker run --rm -it -v %cd%:/var/task lambci/lambda

Only some locally built Docker images fail to work on remote server (error: "No command specified")

I have a perplexing Docker problem. I am running Docker on my Mint laptop and on a Ubuntu VPS. I have been able to build images in the past locally and send them to the server and have them run there. However, for clarity, the ones that work were probably built when I was running Ubuntu locally (more on that later).
I have an example based on Alpine:
FROM alpine:3.5
# Do a system update
RUN apk update
ENTRYPOINT ["sleep", "3"]
I build like so, and send to the remote:
docker build -t alpine-sleep .
docker save alpine-sleep | gzip > alpine-sleep.tgz
rsync --progress alpine-sleep.tgz myserver.example.com:/path/to/images/
I then unpack/import on the remote, and run, thus:
docker import /path/to/images/alpine-sleep.tgz alpine-sleep
docker run -it alpine-sleep
I get this console reply:
docker: Error response from daemon: No command specified.
See 'docker run --help'.
However, if I copy the Dockerfile to the remote, then do this:
docker build -t alpine-sleep-localbuild .
docker run -it alpine-sleep-localbuild
then I get the sleep working fine.
My Docker and kernel versions locally:
jon#jvb ~/alpine_test $ uname -r
4.4.0-79-generic
jon#jvb ~/alpine_test $ docker -v
Docker version 1.12.6, build 78d1802
And remotely:
root#vps:~/alpine-sleep# uname -r
3.13.0-24-generic
root#vps:~/alpine-sleep# docker -v
Docker version 17.05.0-ce, build 89658be
I wonder, does the major difference in the kernel make a difference? I expect 3.13 to 4.4 is quite a big jump. I don't recall what version of the kernel I was using when I build things when I was running Ubuntu locally, but it would not surprise me if it is was 3.x.
The other thing that strikes me as unexpected is the high variation in Docker version numbers. How do I have version 1.x locally, and 17.x remotely? Has the project been through a version re-numbering?
Update
I've just checked the kernel version when I was running Ubuntu locally, and that was:
4.4.0-75-generic
So, this makes me think that a major kernel discrepancy could not be to blame.
The issue is that Docker won't warn you when you use the wrong combination of save/load and export/import. You save/load an image, and you export/import a tar file from a container. Since you are doing a docker save to save your image, you need to do a docker load to restore it on the other host:
docker load < /path/to/images/alpine-sleep.tgz
I have found this very old issue: https://github.com/moby/moby/issues/1826
An image imported via docker import won't know what command to run. Any image will lose all of its associated metadata on export, so the default command won't be available after importing it somewhere else.
So, run it with the entrypoint:
docker run --entrypoint sleep alpine-sleep 3

Docker image for sailsjs development on macosx hangs

I have a docker image build on Arch Linux (sailsjs-dev) with node and sailsjs which I would like to use for development, mounting the app directory inside the container as follows:
docker run --rm --name testapp -p 1337:1337 -v $PWD:/app \
sailsjs-dev sails lift
$PWD is the directory with the sails project.
This works fine on linux, but if I try to run it on macosx (with docker-machine) it hangs forever at the very beginning, with log level set on silly (in config/log.js):
info: Starting app...
There is no other output, this is all we get.
Note, the same docker image works perfectly also on mac with an express app. What could be peculiar of sail that causes the problem?
I can also add that on a mac docker uses a virtualbox instance named docker machine.
We solved it running npm install from within the docker container:
docker run --rm --name testapp -p 1337:1337 -ti -v $PWD:/app \
sailsjs-dev /bin/bash
npm install --no-bin-links
--no-bin-links avoids the creation of symlinks.

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