I have just started Jenkins setup on docker. I started docker container and am planning to run the ANT script I have written, this is where problems started.
Jenkins kept on reporting
ERROR: Unable to find build script at /var/jenkins_home/workspace/SampleSCM/.SampleProject/build.xml
I am not sure how to access /var/Jenkins_home in my local host. Can someone please help ?
Thanks.
You won't find this location on your laptop, because it is not there. It is inside the docker container.
Normally you would checkout out the sources as part of your build. You do not put them there yourself.
If you want to see the files you can use the jenkins gui, or ssh/attach your container (docker attach) and look in there. The idea about docker is that it runs isolated, unless you tell it to map volumes (See here for a reference)
Related
I have Jenkins configured with lots of jobs that I would like to put into Docker container.
Is there a easy way to do such thing?
PS I'm completely new to docker, therefore good guide would be great.
Had to do the same some month ago.
I used ThinBackup to extract the complete jenkins_home and move it to another server. This can be mounted inside a docker container and your Jenkins should work as before. But since your old Jenkins is still running there is no risk if it should fail for some reason.
You can follow this (where jenkins-data is the backup):
https://medium.com/#chrisemerson/first-time-setup-with-jenkins-on-docker-f0632dce9853
If you use Docker inside Jenkins you have to mount the docker.sock of the host as well, if not you can leave out that part.
I am currently running a Jenkins with Docker. When trying to build docker apps, i am facing some doubt on if i should use Docker in Docker (Dind) by binding the /var/run/docker.sock file or by installing another instance of docker in my Jenkins Docker. I actually saw that previously, it was discouraged to use something else than the docker.sock.
I don't actually understand why we should use something else than the docker daemon from the host apart from not polluting it.
sources : https://itnext.io/docker-in-docker-521958d34efd
Best solution for "jenkins in docker container needs docker" case is to add your host as a node(slave) in jenkins. This will make every build step (literally everything) run in your host machine. It took me a month to find perfect setup.
Mount docker socket in jenkins container: You will lose context. The files you want to COPY inside image is located inside workspace in jenkins container and your docker is running at host. COPY fails for sure.
Install docker client in jenkins container: You have to alter official jenkins image. Adds complexity. And you will lose context too.
Add your host as jenkins node: Perfect. You have the contex. No altering the official image.
Without completely understanding why you would need to use Docker in Docker - I suspect you need to meet some special requirements considering the environment in which you build the actual image, may I suggest you multistage building of docker images? You might find it useful as it enables you to first build the building environment and then build the actual image (hence the name 'multistage-building). Check it out here: https://docs.docker.com/develop/develop-images/multistage-build/
I currently run a Jenkins instance inside a Docker container. I've been doing some experimenting with Jenkins and their pipelines. I managed to make my Maven app build successful using a Jenkinsfile.
Right now I am trying to automatically deploy the app I built to a docker container that's a sibling to the Jenkins container. I did already mount the /var/run/docker.sock so I have access to the parent docker. But right now I can't seem to find any good information to guide me through the next part, which is modifying the Jenkinsfile to deploy my app in a new container.
How would I go over and run my Maven app inside a sibling docker container?
It might be more appropriate to spin up a slave node (a physical or virtual box) and then run something in there with docker.
If you check your instance URL: https://jenkins.address/job/myjob/pipeline-syntax/
You will find more information about what are the commands you need for this.
Anyway best way to do this is to actually create a dockerfile and as a step copy the artifact in it, push the image to a registry and then find somewhere to deploy the just built image
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....
Is there a way to do automation with Jenkins to deploy and run containers? I heard we can use the Docker plugins for it. But there isn't any tutorials or info that explains how we can use Jenkins and Docker together. Anyone who uses them both care to share?
First off in my implementation of things Jenkins is actually a container in Docker.
Here's where it may seem things get bizarre: I actually install docker-ce inside of that container, not because I want to run Docker-in-Docker. I disable the Docker daemon from running (sysctl) but I want the command line.
I install docker-compose and docker-machine on the Jenkins host and add the "jenkins" userid to the docker group.
There's a bunch of other steps that I do but basically they are the same steps that a user is going to go through (except it's all in my Docker file) and I add the results of "docker-machine env" to the global variables in the Jenkins configuration.
head spinning yet?
Applications I have Jenkins deploying all have a "jenkins" subdirectory with a Jenkins file in it to perform the dirty work as a pipeline. (build/test/deploy)
Deployments for Java apps for instance involve copying the warfile for the application to the correct directory and when the container (or containers) start the application engine (tomcat, Jboss, whatever) picks it up and the application runs.
Have a look at
https://registry.hub.docker.com/search?q=jenkins&searchfield=
and at some Dockerfiles such as
https://registry.hub.docker.com/u/niaquinto/jenkins/dockerfile/
or
https://registry.hub.docker.com/u/aespinosa/jenkins/dockerfile/