Finding the pid by grepping might be error prone. Alternative option would be to use ControlPath and ControlMaster options of SSH. This way you will be able to have your ssh command listen on a control socket and wait for commands from subsequent ssh calls.
Try this
ssh -D localhost:8087 -S /tmp/.ssh-aws-gateway-vpc1 -M -fN aws-gateway-vpc1 # (...) # later, when you want to terminate ssh connection ssh -S /tmp/.ssh-aws-gateway-vpc1 -O exit aws-gateway-vpc1 The exit command lets you kill the process without knowing the PID. If you do need the PID for anything, you can use the check command to show it:
$ ssh -S /tmp/.ssh-aws-gateway-vpc1 -O check aws-gateway-vpc1 Master running (pid=1234) 
