如何在jenkins管道的docker容器中运行python脚本

Question

I have a docker image in dockerhub that I want to add as an agent in my jenkins pipeline script. As a part of the image, I perform git clone to fetch a repository from github that has multiple python scripts which corresponds to multiple stages in my jenkins pipeline. I tried searching everywhere but I'm not able to find relevant information that talks about how to access the files inside a docker container in jenkins pipeline.

I'm running jenkins on a VM and it has docker installed. The pipeline performs a build on a docker container. Since there are many steps involved in every single stage of the pipeline, I tried to use python API as much as possible.

This is how my dockerfile looks like and the image builds successfully and I'm able to host it in dockerhub. When I run the container, I'm able to see "jenkins_pipeline_scripts" directory which contains all the necessary python scripts for the pipeline stages.

FROM ros:melodic-ros-core-stretch

RUN apt-get update && apt-get -y install python-pip

RUN git clone <private-repo with token>

This is how my current jenkins pipeline script looks like.

pipeline {
    agent {
        docker {
            image '<image name>'
            registryUrl 'https://registry.hub.docker.com'
            registryCredentialsId 'docker-credentials'
            args '--network host -u root:root'
        }
    }

    stages {
        stage('Test') {
            steps {
                sh 'python jenkins_pipeline_scripts/scripts/test.py'   
            }
        }
    }
}

This is the error I'm getting when I execute the job.

$ docker top 05587cd75db5c4282b86b2f1ded2c43a0f4eae161d6c7d7c03d065b0d45e1 -eo pid,comm
[Pipeline] {
[Pipeline] stage
[Pipeline] { (Test)
[Pipeline] sh
+ python jenkins_pipeline_scripts/scripts/test.py
python: can't open file 'jenkins_pipeline_scripts/scripts/test.py': [Errno 2] No such file or directory

Answer 1

When Jenkins Pipeline to launch the agent container, it will change the container's WORKDIR via -w option and mount the Jenkins job's workspace folder via -v option.

As a result of both options, the Jenkins job's workspace folder will becomes your container's WORKDIR .

Following is my jenkins job console output:

docker run -t -d -u 29001:100 
-w /bld/workspace/test/agent-poc 
-v /bld/workspace/test/agent-poc:/bld/workspace/test/agent-poc:rw,z 
-v /bld/workspace/test/agent-poc@tmp:/bld/workspace/test/agent-poc@tmp:rw,z 
-e ******** -e ******** -e ******** -e ******** 
docker.hub.com/busybox cat

You clone the code when build the image and they are not inside the WORKDIR , thus reports no such file error.

Two approaches to fix your issue.

1) cd your code folder at firstly, you should know that path.

    stage('Test') {
        steps {
            sh '''
              cd <your code folder in container>
              python jenkins_pipeline_scripts/scripts/test.py
            '''   
        }
    } 

2) move git clone code repo from Dockerfile into pipeline stage

As I explained at begin, your job's workspace will become container's WORKDIR , thus you can clone your code into jenkins job workspace via pipeline step, then you no need to cd <your code folder in container> .