Jenkins does not run docker container as agent - docker

Question

I am new to Jenkins. Sorry if my question is basic.
I am trying to use Jenkins inside a container using the following command:
docker run --name jenkins --privileged -u root -d -p 8080:8080 -p 50000:50000 -v /var/run/docker.sock:/var/run/docker.sock:Z -v $(which docker):/usr/bin/docker -v jenkins_home:/var/jenkins_home jenkins/jenkins:lts
and after initializing Jenkins by its web page on localhost:8080, I installed docker pipeline and docker plugin plugins and restarted container. Then I created a multibranch pipeline and used my repositories to pull code from. The jenkins file in my repo:
pipeline {
agent {
docker {
image 'python'
}
}
stages {
stage('build') {
steps {
sh 'python --version'
}
}
}
}
However, at first, it didn't work due to some permission problems with docker. I noticed that docker socket inside the container had a uid and gid of nobody. Then I tried to change docker permission in my host machine to 666. Then, it no longer had the permission problem. But, still it doesn't run python --version command inside the container. I have also to add --entrypoint= as args inside jenkins file, -it entrypoint=/bin/bash, -u root. But none of them worked. Here are the logs of jenkins:
Started by user sobhan
07:20:29 Connecting to https://api.github.com using sobhansaf/******
Obtained Jenkinsfile from 2bd22bad5bfca8114cd9d98cc4f56b3915dd012e
[Pipeline] Start of Pipeline
[Pipeline] node
Running on Jenkins in /var/jenkins_home/workspace/mypipe_main
[Pipeline] {
[Pipeline] stage
[Pipeline] { (Declarative: Checkout SCM)
[Pipeline] checkout
The recommended git tool is: NONE
using credential cd26ef85-7736-498b-9629-813934e651fb
> git rev-parse --resolve-git-dir /var/jenkins_home/workspace/mypipe_main/.git # timeout=10
Fetching changes from the remote Git repository
> git config remote.origin.url https://github.com/sobhansaf/circlecitest.git # timeout=10
Fetching without tags
Fetching upstream changes from https://github.com/sobhansaf/circlecitest.git
> git --version # timeout=10
> git --version # 'git version 2.30.2'
using GIT_ASKPASS to set credentials
> git fetch --no-tags --force --progress -- https://github.com/sobhansaf/circlecitest.git +refs/heads/main:refs/remotes/origin/main # timeout=10
Checking out Revision 2bd22bad5bfca8114cd9d98cc4f56b3915dd012e (main)
> git config core.sparsecheckout # timeout=10
> git checkout -f 2bd22bad5bfca8114cd9d98cc4f56b3915dd012e # timeout=10
Commit message: "Update Jenkinsfile"
> git rev-list --no-walk eb8007c2dd9171cf306a04b75cdc48b9cb0da32e # timeout=10
[Pipeline] }
[Pipeline] // stage
[Pipeline] withEnv
[Pipeline] {
[Pipeline] isUnix
[Pipeline] withEnv
[Pipeline] {
[Pipeline] sh
+ docker inspect -f . python
.
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] withDockerContainer
Jenkins seems to be running inside container ccd4d26ae72e22da420697318327033c77e8ff720034a8573a384d6ba442ca4b
but /var/jenkins_home/workspace/mypipe_main could not be found among []
but /var/jenkins_home/workspace/mypipe_main#tmp could not be found among []
$ docker run -t -d -u 0:0 -w /var/jenkins_home/workspace/mypipe_main -v /var/jenkins_home/workspace/mypipe_main:/var/jenkins_home/workspace/mypipe_main:rw,z -v /var/jenkins_home/workspace/mypipe_main#tmp:/var/jenkins_home/workspace/mypipe_main#tmp:rw,z -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** python cat
$ docker top 453918fd912510c869adad2cd3f9fb422108484c7af3ca02a91c42eea9b77b66 -eo pid,comm
[Pipeline] {
[Pipeline] stage
[Pipeline] { (build)
[Pipeline] sh
process apparently never started in /var/jenkins_home/workspace/mypipe_main#tmp/durable-ef6dc772
(running Jenkins temporarily with -Dorg.jenkinsci.plugins.durabletask.BourneShellScript.LAUNCH_DIAGNOSTICS=true might make the problem clearer)
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
$ docker stop --time=1 453918fd912510c869adad2cd3f9fb422108484c7af3ca02a91c42eea9b77b66
$ docker rm -f 453918fd912510c869adad2cd3f9fb422108484c7af3ca02a91c42eea9b77b66
[Pipeline] // withDockerContainer
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
ERROR: script returned exit code -2
GitHub has been notified of this commit’s build result
Finished: FAILURE
also it is worth mentioning that, after creating a container by Jenkins, when I check container, its command is always a cat command. Could you please help me realize what is wrong?