I want to set the docker container hostname to the machine hostname on which docker is installed. Please note than I want to set the hostname dynamically and don't want to hardcode the machine hostname in my docker run command.
How do I achieve this?
My docker run command:
sudo docker run --name=rabbitmq -d -p 5672:5672 -p 15672:15672 \
-e RABBITMQ_DEFAULT_USER=admin \
-e RABBITMQ_DEFAULT_PASS=admin \
--hostname ?? \
-v rmq_vol:/var/lib/rabbitmq \
rabbitmq:3.9.0
What KamilCuk said.
add to docker run: --hostname $(hostname)
You're just passing in the result of the linux "hostname" command to your docker run configuration.
Related
I'm trying to register a gitlab-runner that is running within Docker as per https://docs.gitlab.com/runner/install/docker.html
docker run \
-p 8093:8093 \
-v /var/run/docker.sock:/var/run/docker.sock \
--mount type=bind,source=/etc/ssl/certs/ca-certificates.crt,target=/etc/ssl/certs/ca-certificates.crt \
gitlab/gitlab-runner:latest register \
--non-interactive \
--executor shell \
--url "$REGISTRATION_URL" \
--registration-token "$REGISTRATION_TOKEN" \
--limit "1" \
--name "cumulus-runner" \
--tls-ca-file="/etc/ssl/certs/ca-certificates.crt" \
--tag-list "cumulus"
When the container starts, the process exits immediately afterwards:
❯ docker run -p 8093:8093 -v /var/run/docker.sock:/var/run/docker.sock --mount type=bind,source=/etc/ssl/certs/ca-certificates.crt,target=/etc/ssl/certs/ca-certificates.crt gitlab/gitlab-runner:latest register -n --executor shell -u "$REGISTRATION_URL" -r "$REGISTRATION_TOKEN" --limit "1" --name "cumulus-runner" --tls-ca-file="/etc/ssl/certs/ca-certificates.crt" --tag-list "cumulus" Runtime platform arch=amd64 os=linux pid=6 revision=7a6612da version=13.12.0
Running in system-mode.
Registering runner... succeeded runner=jMkWoLVS
Runner registered successfully. Feel free to start it, but if it's running already the config should be automatically reloaded!
❯ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
62febd5e7573 gitlab-runner:latest "/usr/bin/dumb-init …" 4 minutes ago Exited (0) 4 minutes ago practical_shamir
When I run the command outside of docker, the gitlab-runner process is kept alive:
❯ ps aux | grep gitlab-
root 1717 0.0 0.1 1904556 21200 ? Ssl Jun08 0:35 /usr/bin/gitlab-runner run --working-directory /var/lib/gitlab-runner --config /etc/gitlab-runner/config.toml --service gitlab-runner --syslog --user gitlab-runner
Am I overlooking something? I feel like the container should be kept alive?
In my test, I did not use -p
docker volume create gitlab-runner-config
docker run -d --name gitlab-runner --restart always \
-v /var/run/docker.sock:/var/run/docker.sock \
-v gitlab-runner-config:/etc/gitlab-runner \
gitlab/gitlab-runner:latest
or you can check the logs, what's the error?
docker logs gitlab-runner
I'm trying to run a Docker build within a Docker container based upon Ubuntu 20.04. The container needs to run as a non-root use for the build process before the Docker build occurs.
Here's some snippets of my Dockerfile to show what I'm doing:
FROM amd64/ubuntu:20.04
# Install required packages
RUN apt-get update && apt-get install -y software-properties-common
build-essential \
libssl-dev \
openssl \
libsqlite3-dev \
libtool \
wget \
autoconf \
automake \
git \
make \
pkg-config \
cmake \
doxygen \
graphviz \
docker.io
# Add user for CI purposes
RUN useradd -ms /bin/bash ciuser
RUN passwd -d ciuser
# Set docker group membership
RUN usermod -aG docker ciuser
# Run bash as the non-root user
CMD ["su", "-", "ciuser", "/bin/bash"]
When I run the container up, and try to run docker commands, I get an error:
$ docker run -ti --privileged=true -v /var/run/docker.sock:/var/run/docker.sock ci_container_staging
ciuser#0bb768506106:~$ docker ps
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.40/containers/json: dial unix /var/run/docker.sock: connect: permission denied
If I remove the running as ciuser it works ok:
$ docker run -ti --privileged=true -v /var/run/docker.sock:/var/run/docker.sock /ci_container_staging
root#d71654581cec:/# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
d71654581cec ci_container_staging "/bin/bash" 3 seconds ago Up 2 seconds vigilant_lalande
root#d71654581cec:/#
Where am I going wrong with setting up Docker via Dockerfile and then setting user to run as?
amd64/ubuntu:20.04 has a docker group with group id 103. Most likely the gid of the docker group for your local machine is not 103 (check getent group docker). So even though ciuser is part of the docker group, the id is different and so the user is not granted access to the docker socket.
A simple fix would be to change the gid of the docker group in the container to match your host's:
RUN groupmod -g <HOST_DOCKER_GROUP_ID> docker
There are plenty of other ways to solve issues with mapping uid/gid to docker containers but this should give you enough information to move forward.
Example/more info:
# gid on docker socket is 998
root#c349e1d13b76:/# ls -al /var/run/docker.sock
srw-rw---- 1 root 998 0 Apr 12 14:54 /var/run/docker.sock
# But gid of docker group is 103
root#c349e1d13b76:/# getent group docker
docker:x:103:ciuser
# root can `docker ps`
root#c349e1d13b76:/# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c349e1d13b76 nonroot:latest "/bin/bash" About a minute ago Up About a minute kind_satoshi
# but fails for ciuser
root#c349e1d13b76:/# runuser -l ciuser -c 'docker ps'
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.24/containers/json: dial unix /var/run/docker.sock: connect: permission denied
# change docker gid in the container to match the one on the socket/localhost
# 998 is the docker gid on my machine, yours may (will) be different.
root#c349e1d13b76:/# groupmod -g 998 docker
# run `docker ps` again as ciuser, works.
root#c349e1d13b76:/# runuser -l ciuser -c 'docker ps'
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c349e1d13b76 nonroot:latest "/bin/bash" About a minute ago Up About a minute kind_satoshi
Part of the Docker metadata when it starts a container is which user it should run as; you wouldn't generally use su or sudo.
USER ciuser
CMD ["/bin/bash"] # or the actual thing the container should do
This is important because you can override the user when the container starts up, with the docker run -u option; or you can docker run --group-add extra groups. These should typically be numeric group IDs, and they do not need to exist in the container's /etc/passwd or /etc/group files.
If the host's Docker socket is mode 0660 and owned by a docker group, you can look up the corresponding group ID and specify the container process has that group ID:
docker run \
--group-add $(getent group docker | cut -d: -f3) \
-v /var/run/docker.sock:/var/run/docker.sock \
--rm \
ci_container_staging \
docker ps
(The container does not specifically need to be --privileged, though nothing stops it from launching additional privileged containers.)
I run a docker container by
[root#compute maven]# docker run -d -p 8083:8080 --name jenkins -v /usr/bin/docker:/usr/bin/docker -v /var/run/docker.sock:/var/run/docker.sock -v /root/maven-tar/:/root csphere/jenkins:1.609
e40f704478e5e37ee3f214a1469f5851a78c324099610a12e79238b8599e194a
Then I get into the container by "docker exec"
[root#compute maven]# docker exec -it jenkins /bin/bash
jenkins#e40f704478e5:
I try run "docker ps",it showes this
jenkins#e40f704478e5:/$ docker ps
/usr/bin/docker: 2: .: Can't open /etc/sysconfig/docker
I just started a Jenkins docker container with a mounted docker socket like the following:
docker run -d \
--publish 8080:8080 \
--publish 50000:50000 \
--volume /my_jenkins_home:/var/jenkins_home \
--volume /var/run/docker.sock:/var/run/docker.sock \
--restart unless-stopped \
--name my_jenkins_container \
company/my_jenkins:latest
Then I bash into the container like this:
docker exec -it my_jenkins_container bash
A tool 'docker' command in a Jenkins pipeline script has automatically installed a Docker binary at the following path: /var/jenkins_home/tools/org.jenkinsci.plugins.docker.commons.tools.DockerTool/docker/bin/docker
However, when I try to run Docker commands from that Docker binary (assuming that it will connect with the Docker socket that has been mounted at /var/run/docker.sock) it returns the following error:
$ /var/jenkins_home/tools/org.jenkinsci.plugins.docker.commons.tools.DockerTool/docker/bin/docker images
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
How can I ensure that this Docker binary (the binary that has been automatically installed via the Jenkins' tool 'docker' command) runs its Docker commands by connecting to the mounted Docker socket at /var/run/docker.sock?
Short Answer:
The file permissions of the mounted Docker socket file had to be revised.
Long Answer:
When I simply tried to execute /path/to/dockerTool/bin/docker ps -a on the Docker container, it was producing an error.
$ docker exec -it my_jenkins_container bash -c "/var/jenkins_home/tools/org.jenkinsci.plugins.docker.commons.tools.DockerTool/docker/bin/docker ps -a"
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
Then, when I tried to execute /path/to/dockerTool/bin/docker ps -a with user=root, it worked fine.
$ docker exec -it --user=root my_jenkins_container bash -c "/var/jenkins_home/tools/org.jenkinsci.plugins.docker.commons.tools.DockerTool/docker/bin/docker ps -a"
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c9dd56411efe company/my_jenkins:latest "/bin/tini -- /usr/lo" 49 seconds ago Up 49 seconds 0.0.0.0:8080->8080/tcp, 0.0.0.0:50000->50000/tcp my_jenkins_container
So it means I just needed to set the right permissions to the Docker socket. All I had to do was chgrp the socket file to the jenkins group so that the jenkins group/users can read/write to that socket file (the before & after of the chgrp command is included here):
$ docker exec -it my_jenkins_container bash -c "ls -l /var/run/docker.sock"
srw-rw---- 1 root 999 0 Jan 15 08:29 /var/run/docker.sock
$ docker exec -it --user=root my_jenkins_container bash -c "chgrp jenkins /var/run/docker.sock"
$ docker exec -it my_jenkins_container bash -c "ls -l /var/run/docker.sock"
srw-rw---- 1 root jenkins 0 Jan 15 08:29 /var/run/docker.sock
After that, executing /path/to/dockerTool/bin/docker ps -a as a non-root user worked fine
$ docker exec -it my_jenkins_container bash -c "/var/jenkins_home/tools/org.jenkinsci.plugins.docker.commons.tools.DockerTool/docker/bin/docker ps -a"
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
c9dd56411efe company/my_jenkins:latest "/bin/tini -- /usr/lo" 3 minutes ago Up 3 minutes 0.0.0.0:8080->8080/tcp, 0.0.0.0:50000->50000/tcp my_jenkins_container
I created a tar file of live centOS with:
tar --numeric-owner \
--exclude=/proc \
--exclude=/sys \
--exclude=/mnt \
--exclude=/var/cache \
--exclude=/usr/share/doc \
--exclude=/tmp \
--exclude=/var/log \
-zcvf /mnt/rhel7-base.tar.gz /
and then run
cat rhel7-base.tar.gz | docker import - rhel7/01
to load it into docker. It finished without an error and I can find it with
docker images command. Finally, i tried to run it docker run -i -t rhel7/01 (also without -i,-t switches), but nothing result
[root#vhp~]# docker run rhel7/01
[root#vhp~]#
I'm wondering if any one corrects me.
Not 100% sure, but it seems that you're missing command for docker to execute inside your image, try:
[root#vhp~]# docker run -it rhel7/01 bash # this should drop you into bash inside docker container
Also you can check if container is running with docker ps -a
It better you pull centos image from official docker repo,then configure according to your use and then push image to a registry.It is easy and simple.
docker push imagename
Make a Dockerfile like this:
#- pull base image.
FROM centos:latest
#- setting locale
ENV LANG en_US.UTF-8
ENV LANGUAGE en_US:en
ENV LC_ALL en_US.UTF-8
#- add for terminal
ENV TERM xterm