Get output from a shell script that does ssh two level - bash

Question

I have two shell scripts like below:
Script1:
ssh -q -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null my_username#jump_box <<EOF
ls
ssh -q -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null actual_host <<EOF1
sudo docker ps --format='{{json .}}'
EOF1
EOF
Script2:
details=nothing
ssh -q -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null my_username#jump_box <<EOF
ls
details=$(ssh -q -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null actual_host "sudo docker ps --format='{{json .}}'")
EOF
echo "${details}"
I need the docker details in a varilable in my local machine so that I can do some operations on it. The first script runs fine and I can see the output of the docker command on my local machine but the second script doesn't work. It seems to be hung/stuck and doesn't do anything and I have to forcefully quit it.

Answer 1

Like the comment from #Gordon Davisson, use a jumpbox.
But you can define it in the ~/.ssh/config file, too.
HOST my_jump_box
hostname jump_box
user my_username
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
HOST actual
hostname actual_hostname
user actual_user
ProxyJump my_jump_box
StrictHostKeyChecking no
UserKnownHostsFile /dev/null
RemoteCommand sudo docker ps --format='{{json .}}'"
Then you can just use ssh actual
To fetch the output details=$(ssh actual).
Btw. Your specific problem could also be solved by changing script2 to:
#!/bin/bash
details=$(./script1)
echo "$details"