Jenkinsfile: connect to a server and perform operations on the server - jenkins

Question

In Jenkinsfile I am trying to login to a server and from there run docker-compose. However, I am getting an AccessDeniedException error. Root user has permissions to all folders on the server.
I assume I have a thinking error: I suspect that after ssh to the server, the dir command doesn't not run in the server but rather where the jenkins is run.
Jenkinsfile:
pipeline {
agent any
environment {
PATH = "$PATH:/usr/local/bin/"
}
stages {
stage('Deploy to digital ocean') {
steps {
sshagent(['my-private-ssh-key']) {
sh """
ssh root#host
"""
dir("/var/www/car_prices"){
sh "docker-compose down"
}
}
}
}
}
}
Error stack:
[Pipeline] dir
Running in /var/www/car_prices
[Pipeline] {
[Pipeline] sh
[Pipeline] }
[Pipeline] // dir
[Pipeline] }
$ ssh-agent -k
unset SSH_AUTH_SOCK;
unset SSH_AGENT_PID;
echo Agent pid 67144 killed;
[ssh-agent] Stopped.
[Pipeline] // sshagent
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] }
[Pipeline] // withEnv
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
java.nio.file.AccessDeniedException: /var/www
Question:
1. Why does it throw an error?

Answer 1

You need to use ssh to do the job for you, which is rather straight forward:
...
sshagent(['my-private-ssh-key']) {
sh """
ssh root#host "cd /var/www/car_prices; docker-compose down"
"""
}
...
This is kind of ugly, but works. If you care, you can split commands into multiple lines for better readability. This approach becomes even trickier if you want to provide some more complex functionality, like error handling.