open gnome terminal tabs programmatically and execute commands in sequence - shell

Question

When working remotely, I have a series of tabs that I open in gnome-terminal, and commands that I execute in them. I would like to automate all this setup as a single command.
If these commands could run independently and in parallel, I'd just adapt the answer to this question. In fact, I tried, using the following shell script:
gnome-terminal --working-directory="/home/superelectric" --tab -t "gate" -e 'bash -c "export BASH_POST_RC=\"ssh gate_tunnel\"; exec bash"' --tab -t "mydesktop" -e 'bash -c "export BASH_POST_RC=\"ssh tunneled_mydesktop\"; exec bash"'
Spread out over multiple lines, for readability:
gnome-terminal \
--working-directory="/home/superelectric" \
--tab \
-t "gate" \
-e \
'bash -c "export BASH_POST_RC=\"ssh gate_tunnel\"; exec bash"' \
--tab \
-t "mydesktop" \
-e \
'bash -c "export BASH_POST_RC=\"ssh tunneled_mydesktop\"; exec bash"'
The first part opens a tab, names it 'gate', and executes 'ssh gate_tunnel' within it. This is an ssh alias that opens a tunnel to 'mydesktop' at school, through the school's outward-facing server, 'gate'.
The second part opens another tab, names it 'mydesktop', and executes 'ssh tunneled_mydesktop' within it. This is another ssh alias, which connects to mydesktop through the tunnel.
~/.ssh/config:
Host gate_tunnel
LocalForward 8023 <my_desktop_at_school>:22
HostName <my_school_server>
That's the theory. In practice, the two commands execute in parallel, whereas I need to ensure that the first tab's command (open tunnel) completes before executing the second tab's command (connect through tunnel).
Is there maybe some command I can execute in the second tab, that 'waits' until the ssh tunnel is opened?

Answer 1

Ok, I think i get it. As i mentioned in the comments the first thing that comes to mind for reaching your school desktop from the outside is to ssh into the school gate and from there ssh into your desktop with something like:
$ ssh -t gate.school.edu ssh desktop_name
There's only one tab then, so your problem doesn't exist.
However there's something very cool with your current setup:
From home it's almost as if you had a direct connection to your desktop machine, so you can scp into it directly and forget about gate. With the solution above that's not possible anymore because we end up with an indirect connection: If you want to scp you have to do it from gate and that sucks.
Check out this article on using ssh's ProxyCommand feature:
Transparent Multi-hop SSH
You get the best of both worlds then :)

Answer 2

Hmm... this may not be a perfect solution. Ideally you should use something that monitors the ssh connection. But, you can check the ssh process with ps. And wait for ssh command to come alive.
#!/bin/bash
COUNTER=0
while [ $COUNTER -lt 10 ]; do # try 10 times
if ps aux ¦ grep <my_desktop_at_school> then
# the tunnel connected now execute the second command
'bash -c "export BASH_POST_RC=\"ssh tunneled_mydesktop\"; exec bash"'
else
continue # or you could do something here if you wish
fi
sleep 10 # sleep for 10 seconds and try again
let COUNTER=COUNTER+1
done
You will have to run this script in the second tab.
Hope it helps.