docker中的jenkins-无法通过unix：///var/run/docker.sock连接到Docker守护程序。 泊坞窗守护程序正在运行吗？

Question

I'm running https://hub.docker.com/r/jenkinsci/blueocean/ in docker. Trying to build a docker image in jenkins.

but i get the following error:

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

clearly the jenkins version in docker does not have access to the docker binary.

I confirmed this by,

docker exec -it db4292380977 bash
docker images
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

"db4292380977" is the running container. It shows the same error.

Question:

• how do I allow access to docker in the jenkins container?

Answer 1

The docker client is installed on the jenkinsci/blueocean image, but not the daemon. Docker client will use the daemon (by default via the socket unix:///var/run/docker.sock ). Docker client needs a Docker daemon in order to work, you can read Docker Architecture for more info.

What you can do:

Use docker-in-docker (DinD) image

Library Docker image provides a way to run a Docker daemon in Docker, you can then use it from another container. For example, using plain docker CLI:

docker run --name docker-dind --privileged -d docker:stable-dind
docker run --name jenkins --link=docker-dind -d jenkinsci/blueocean
docker exec jenkins docker -H docker-dind images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

Docker daemon runs in docker-dind container and can be reached using the same hostname. You just need to provide the docker client with the daemon host ( -H docker-dind in the example, you can also use DOCKER_HOST env variable as described in the doc ).

Mount host machine /var/run/docker.sock in your container

As described by @Herman Garcia answer:

docker run -p 8080:8080 --user root \
     -v /var/run/docker.sock:/var/run/docker.sock jenkinsci/blueocean

Answer 2

You need to mount your local /var/run/docker.sock and run the container as root user

NOTE: this might be a security flaw so be careful who has access to the jenkins container

docker run -p 8080:8080 --user root \
     -v /var/run/docker.sock:/var/run/docker.sock jenkinsci/blueocean

you will be able to execute docker inside the container

➜  ~  docker exec -it gracious_agnesi bash                                                                                              
bash-4.4# docker ps                                                                                                                     
CONTAINER ID        IMAGE                 COMMAND                  CREATED             STATUS              PORTS                        
       NAMES                                                                                                                            
c4dc85b0d88c        jenkinsci/blueocean   "/sbin/tini -- /usr/…"   18 seconds ago      Up 16 seconds       0.0.0.0:8080->8080/tcp, 50000
/tcp   gracious_agnesi

Answer 3

Just only try to do the same command but with sudo in the beginning

For example

sudo docker images
sudo docker exec -it db4292380977 bash

To avoid use sudo in the future you should run this command in Unix OS

sudo usermod -aG docker <your-user>

Change for the user that you are using at this moment. Remember to log out and back in for this to take effect! More information about Docker installation click here