Jenkins docker - running a container, executing shell script etc - docker

Question

I'm trying to run docker containers in the Jenkins Pipeline.
I have the following in my Jenkinsfile:
stage('test') {
steps {
script {
parallel (
"gatling" : {
sh 'bash ./test-gatling.sh'
},
"python" : {
sh 'bash ./test-python.sh'
})
}
}
}
In the test-gatling.sh I have this:
#!/bin/bash
docker cp RecordedSimulation.scala denvazh/gatling:/RecordedSimulation.scala
docker run -it -m denvazh/gatling /bin/bash
ls
./gatling.sh
The ls command is there just for test, but when it's executed it lists files and folders of my github repository, rather than the files inside the denvazh/gatling container. Why is that? I thought the docker run -it [...] command would open the container so that commands could be run inside it?
================
Also, how do I run a container and just have it running, without executing any commands inside it? (In the Jenkins Pipeline ofc)
I'd like to run: docker run -d -p 8080:8080 -t [my_container] and access it on port 8080. How do I do that...?

Answer 1

If anyone has the same or similar problem, here are the answers:
Use docker exec [name of container] command, and to run any terminal commands inside a container, add /bin/bash -c "[command]"
To be able to access a container/app that is running on any port from a second container, when starting the second container run it with --net=host parameter