How to make sshd startup after zerotier-one?

[pvanthony]

I have bind sshd to the zerotier-one ip address.
That works.

After reboot, sshd dies because it cannot bind to zerotier-one interface.
Tried adding zerotie-one.service to After, Wants and Requires in systemd
But still does not work.

How to make sshd to startup only after zerotier-one has started up and got an ip address?

[senseivita]

hmm… How about from the other side? Add in sshd.service: RequiredBy=, or Before=/After=. Or, create a .target unit to manipulate service launch at your will.

Off the top of my head, maybe a launch a .timer unit as part of ZeroTier’s (so you know ZT has started) that waits just a little bit after (OnActiveSec=##) starting to restart sshd…or maybe reset the failed unit, depending on the error given when it died.

Good luck. =)

[pvanthony]

Thank you for the advice.

Did the following and it seems to work. May not be perfect so please continue to advice.

Here is the systemd startup for zerotier.

[Unit]
Description=ZeroTier One
After=network-online.target network.target
Wants=network-online.target

[Service]
ExecStart=/usr/sbin/zerotier-one
Restart=always
KillMode=process
ExecStartPost=/usr/bin/sleep 30 #<-- added this to make 30sec delay
ExecStartPost=-/root/scripts/zerotier/restart_ssh #<-- this is the script that does the work.
                                                  # Please note the "-" at the start
                                                  # so the systemctl will continue even with a fail

[Install]
WantedBy=multi-user.target

Here is the script.

#!/usr/bin/bash

#script to restart ssh if ssh is failed
/usr/bin/systemctl is-failed --quiet ssh.service && /usr/bin/systemctl restart ssh.service
/usr/bin/systemctl is-failed --quiet dovecot.service && /usr/bin/systemctl restart dovecot.service
/usr/bin/systemctl restart postfix.service
# strange for me. Even the dovecot and postfix needs to be restarted
# might be because of the zerotier affects the network.