I'd like to run the postgres docker image instead of the postgres binary provided by cloudbees due to the lack of uuid and postgis support. However, the only two docker plugins I have access to are CloudBees Docker Custom Build Environment Plugin and Docker Commons Plugin. I'd like to avoid the extra complexity associated with the custom build env plugin due to the need to setup docker in docker(outer image for the slave and inner image for postgres).
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I'm running Jenkins version 2.176.3 on Openshift online. And I want to build a pipeline which uses Docker commands to build the image. When I tried to build it gives me an error saying Docker command not found.
I think that is because I don't have Docker installed in Jenkins. I tried to do that using the Jenkins Plugin Manager but the Docker plugin requires Jenkins version 2.19 or later.
I also tried accessing the Jenkins container using oc CLI and tried to install Docker but did not work.
So what would be the best method for me to install Docker inside Jenkins?
The error means you need to have/install docker inside your agent/slave image. For a test purpose try to run your pipeline with docker images, which already contain docker tool.
I am trying to start a container using Jenkins and a Dockerfile in my SCM.
Jenkins uses the Dockerfile from my SCM repository and builds the image on a remote server having a Dockerfile. This is done using the "cloud bees docker build and publish plugin".
When I ssh to the server, I see that the image has been built with the tags I had defined in Jenkins.
# docker image ls
What I am not able to do is run a container for the image that has been built. How to get the image-id and start the container? Shouldn't it have been very simple given many plugins are provided?
Could your problem be related to how to refer to the recently created docker in order tu run it? Can you provide an extract of your pipeline and how you are trying to achieve this?
It that was the case, there are different solutions, one being specifying a tag during the Docker creation, so you can then refer to it to run it.
In reply to how to work with image-ids, the docker build process will return the image id of the docker it creates. You can capture that id, and then use to run the docker.
start the container yourself on the VM by using standard docker run command.
use a software like watchtower to restart the container with an updated version when available
Hi I'm learning how to use Jenkins integrated with Docker and I don't understand what should I do to communicate them.
I'm running Jenkins inside a Docker container and I want to build an image in a pipeline. So I need to execute some docker commands inside the Jenkins container.
So the thing here is where docker come from. I understand that we need to bind mount the docker host daemon (socket) to the Jenkins container but this container still needs the binaries to execute Docker.
I have seen some approaches to achieve this and I'm confused what should I do. I have seen:
bind mount the docker binary (/usr/local/bin/docker:/usr/bin/docker)
installing docker in the image
if I'm not wrong the blue ocean image comes with Docker pre-installed (I have not found any documentation of this)
Also I don't understand what Docker plugins for Jenkins can do for me.
Thanks!
Docker has a client server architecture. The server is the docker deamon and the client is basically the command line interface that allows you to execute docker ... from the command line.
Thus when running Jenkins inside Docker you will need access to connect to the deamon. This is acheieved by binding the /var/run/docker.sock into the container.
At this point you need something to communicate with the Deamon which is the server. You can either do that by providing access to docker binaries. This can be achived by either mounting the docker binaries, or installing the
client binaries inside the Jenkins container.
Alternatively, you can communicate with the deamon using the Docker Rest API without having the docker client binaries inside the Jenkins container. You can for instance build an image using the API.
Also I don't understand what Docker plugins for Jenkins can do for me
The Docker plugin for Jenkins isn't useful for the use case that you described. This plugin allows you to provision Jenkins slaves using Docker. You can for instance run a compilation inside a Docker container that gets automatically provisioned by Jenkins
It is not best practice to use Docker with Jenkins. It is also not a bad practice. The relationship between Jenkins and Docker is not determined in such a manner that having Docker is good or bad.
Jenkins is a Continuous Integration Server, which is a fancy way of saying "a service that builds stuff at various times, according to predefined rules"
If your end result is a docker image to be distributed, you have Jenkins call your docker build command, collect the output, and report on the success / failure of the docker build command.
If your end result is not a docker image, you have Jenkins call your non-docker build command, collect the output, and report on the success / failure of the non-docker build.
How you have the build launched depends on how you would build the product. Makefiles are launched with make, Apache Ant with ant, Apache Maven with mvn package, docker with docker build and so on. From Jenkin's perspective, it doesn't matter, provided you provide a complete set of rules to launch the build, collect the output, and report the success or failure.
Now, for the 'Docker plugin for Jenkins'. As #yamenk stated, Jenkins uses build slaves to perform the build. That plugin will launch the build slave within a Docker container. The thing built within that container may or may not be a docker image.
Finally, running Jenkins inside a docker container just means you need to bind your Docker-ized Jenkins to the external world, as #yamenk indicates, or you'll have trouble launching builds.
Bind mounting the docker binary into the jenkins image only works if the jenkins images is "close enough" - it has to contain the required shared libraries!
So when sing a standard jenkins/jenkins:2.150.1 within an ubuntu 18.04 this is not working unfortunately. (it looked so nice and slim ;)
So the the requirement is to build or find a docker image which contains a compatible docker client for the host docker service is.
Many people seem to install docker in their jenkins image....
I have installed jenkins 2.99 on my ICP V2.1. I have configured a pipeline job to build docker images and push to the local repository in a jenkinsfile, But the docker command is not getting recognised. I am getting the error
docker build -t <tag> .
/<>/script.sh: docker: not found
If docker has to be installed separately, how do we install?
Considering ICP (IBM Cloud Private) is an application platform for developing and managing on-premises, containerized applications, docker should be installed already.
Check, outside of Jenkins, that docker is recognized.
which docker
Then, in the Jenkins page displaying the Job result, check the Environment variable section, and see if the PATH would include the folder where docker is installed.
Basic example of what I want my Jenkinsfile to do:
node {
sh 'docker build -t foo/bar .'
}
It seems like I need to install docker onto the Jenkins slave image that's executing my Jenkinsfile. Is there an easy way of doing this? (That Jenkins slave image is itself a docker container)
Are my assumptions correct?
When running with Jenkins master/slaves, the Jenkinsfile is executed by a Jenkins slave
Jenkins plugins installed via the Manage Plugins section (e.g. the Docker Plugin, or Gcloud SDK plugin) are only installed on the Jenkins masters, therefore I would need to manually build my Jenkins slave docker image and install docker on the image?
Since I also need access to the 'gcloud' command (I'm running Jenkins via Kubernetes Helm/Charts), I've been using the gcr.io/cloud-solutions-images/jenkins-k8s-slave image for my Jenkins slave.
Currently it errors out saying "docker: not found"
My assumption is that you want to docker build inside the Jenkins slave (which is a Kubernetes pod, I assume created by the Kubernetes Jenkins Plugin)
To set the stage, when Kubernetes creates pod that will act as a Jenkins slave, all commands that you execute inside the node will be executed inside that Kubernetes pod, inside one of the containers there (by default there will only be one container, but more on this later).
So you are actually trying to run a Docker command inside a container based on gcr.io/cloud-solutions-images/jenkins-k8s-slave, which is most likely based on the official Jenkins JNLP Slave, which does not container Docker!
From this point forward, there are two approaches that you can take:
use a slightly modified image based on the JNLP slave that also contains the Docker client and mount the Docker socket (/var/run/docker.sock) inside the container.
(You can find details on this approach here).
Here is an image that contains the Docker client and kubectl.
Here is a complete view of how to configure the Jenkins Plugin:
Note that you use a different image (you can create your own and add any binary you want there) and that you mount the Docker socket inside the container.
the problem with the first approach is that you create a new image forked from the official JNLP slave and manually add the Docker client. This means that whenever Jenkins or Docker have updates, you need to manually update your image and entire configuration, which is not that desirable.
Using the second approach you always use official images, and you use the JNLP slave to start other containers in the same pod.
Here is the full file from the image below
Here is the Jenkins Plugin documentation for doing this
As I said, the JNLP image will start a container that you specify in the same pod. Note that in order to use Docker from a container you still need to mount the Docker sock.
These are the two ways I found to achieve building images inside a Jenkins JNLP slave running inside a container.
The example also shows how to push the image using credential bindings from Jenkins, and how to update a Kubernetes deployment as part of the build process.
Some more resources:
deploy Jenkins to Kubernetes as Helm chart, configure plugins to install
Thanks,
Radu M