Uhm. The log message earlier clearly stated you do not have binary called 'ssh' installed inside the docker container.
doveadm(u...@abc.net): Fatal: execvp(ssh) failed: No such file or directory You can install it however with docker exec -it apt install ssh *Alternatively* you can configure doveadm server and use that. service doveadm { inet_listener { port = 12412 } } doveadm_port = 12412 doveadm_password = secretpass Then you can do doveadm backup -D -u user@name tcp:remoteip:12412 Aki > On 15/05/2020 08:02 Gregory Sloop <gr...@sloop.net> wrote: > > > I'm no docker guru - so I'm more than a little out of my depth in this case. > But clearly ssh is installed, because that's what I'm running, and the sshd > allows a connect and I get a return from ls. So, it's working fine outside > the container. > > And I only need to execute doveadm sync inside the container. [Because > that's where docecot/doveadm is installed.] > > So, it sure seems to me that I've got everything in place, at least in terms > of ssh/sshd. I'm not even sure how I'd ssh directly to a sshd inside the > container. > > AT> You need both. sshd where you try to connect to, and ssh on where you > try to connect from. > > AT> Aki > >