Env-vars with prefix PRE_COMMAND are sorted and used to inject commands before autossh is invoked.
NB: you'll need to be really sure you want to inject arbitrary shell commands like this!
docker run \
--cap-add=NET_ADMIN \
-e PRE_COMMAND_03='ping -c5 10.10.10.10' \
-e PRE_COMMAND_02='ip route show' \
-e PRE_COMMAND_01='ip route add 10.10.10.0/24 via 172.17.10.1' \
threatpatrols/autossh -T user@10.10.10.10