I work on a cluster that requires two-factor login for every new connection. When I try creating a remote python interpreter in PyCharm, I can successfully connect, which requires 1 round of two-factor login via Duo. But then, PyCharm tries to test whether rsync works, which requires another round of two-factor authentication:
Successfully connected to rschaef@login.sherlock.stanford.edu:22
> pwd
Failed to execute command
Checking rsync connection...
/usr/bin/rsync -n -e "ssh -p 22 " rschaef@login.sherlock.stanford.edu:
rschaef@login.sherlock.stanford.edu's password:
(rschaef@login.sherlock.stanford.edu) Duo two-factor login for rschaef
Enter a passcode or select one of the following options:
1. Duo Push to XXX-XXX-3013
2. Phone call to XXX-XXX-3013
3. SMS passcodes to XXX-XXX-3013
Passcode or option (1-3):
The problem is that PyCharm gives me no way to specify 1, 2 or 3, so I cannot authenticate again for rsync to complete. Consequently, I cannot move past this rsync step. Can someone please help me?
The comment by OP could serve as a good answer already, I elaborate here slightly.
Multiplexing aggregates all connection into one. To enable multiplexing you should modify ~/.ssh/config on your local machine and add there:
Host *
ControlMaster auto
ControlPath ~/.ssh/control-%r@%h:%p
ControlPersist 10m
You can also limit it to some nodes only by changing Host * into e.g. Host 1.2.3.4.
Security consideration: make sure that the control path is accessible only by you. It is also possible that remote system admin blocks the multiplexing.