Passing arguments for a remote Python script using ssh

Question

Echo Enter the Report ID

read varname

ssh -t root@192.168.10.10 '
  python myscript.py --user User1 --password Password1 --report \$varname
'

I am trying pass an argument 'varname' to a remotely located python script using ssh but unable to do so. Getting an error 'Invalid report uuid provided'

Value for --report looks like as follow efc4c534-5d1d-11e9-844b-fa163e069095

What is the question here? What went wrong when you tried what you did above? — Devesh Kumar Singh, Apr 17 '19 at 00:54
sounds like this has something to do with your program/database and not SSH. Can you log into the machine and run the same command? — Paul H, Apr 17 '19 at 00:59
@PaulH For a static value of --report, program runs both remotely and locally. I would like to provide the value dynamically (during run time). — Yogesh, Apr 17 '19 at 01:02
Why the \ before `$varname`? `varname` is define only locally, not on the remote machine. — Keldorn, Apr 17 '19 at 01:04
@Keldorn I tried without \ and $ but couldn't get it worked. — Yogesh, Apr 17 '19 at 01:06

Keldorn · Accepted Answer · 2019-04-17T01:22:39.133

1

varname is defined locally only, so $varname needs to be expanded:

Use double quotes instead of single quotes, see e.g. https://stackoverflow.com/a/6697781/6352677.
Remove the backslash before $varname.

Echo Enter the Report ID

read varname

ssh -t root@192.168.10.10 "python myscript.py --user User1 --password Password1 --report $varname"

edited Apr 17 '19 at 01:22

answered Apr 17 '19 at 01:15

Keldorn

1,980
15
25

Depending on the value of `varname`, its expansion may need to be quoted on the remote end. `ssh ... "python ... '$varname'"` would suffice as long as you can guarantee that `$varname` itself doesn't contain any single quotes. If it could, things get a lot trickier. – chepner Apr 17 '19 at 01:26
Good point. In the case of OP's example (efc4c534-5d1d-11e9-844b-fa163e069095), that will probably not be necessary. – Keldorn Apr 17 '19 at 01:32
The sketchy thing is, though, that you are logging in to a machine as root using a script that effectively lets you run arbitrary code: consider `varname="; echo gotcha"`. It would be a good idea to validate `varname` against the expected input format and only run `ssh` if the validation succeeds. – chepner Apr 17 '19 at 01:38
True. Feel free to edit or delete my answer. This question looks like a duplicate anyway, and has a negative vote. – Keldorn Apr 17 '19 at 01:47

Passing arguments for a remote Python script using ssh

1 Answers1