How to reproduce :

1. setup a docker4mac machine as a ssh slave
2. run this pipeline :

   node ('slave'){
           docker.image("ubuntu").inside{ 
               sh 'ps -ef'
           }
   }
   

   shell step fail to run docker command.

This is expected as docker4mac client binary is installed under /usr/local/bin which isn't part of non-interactive ssh session PATH. So, never mind, let's declare a docker tool installation

node ('slave'){
    docker.withTool("docker4mac"){ 
        docker.image("ubuntu").inside{ 
            sh 'ps -ef'
        }
    }
}

Still falling.

Not sure about possible workaround.