Establishing SSH Connection from Ignition and executing commands & Python

[Sri_Haran]

Hey All,
This is the Exact task i need to do with, Though i have tried this with python using the library paramiko,
i was unable to find the way for doing can anyone guide me.

Python/Java Library for SSH from Ignition to SSH server computer to run a script

Working on the an application where when I press a button on Ignition, I need the the action to establish a SSH connection to the remote server and run a python script and also get a return value. ParaMiko is a python library and has a lot of Dependencies which I am assuming wont work in Jython [ I haven’t tried it] Wanted to get some guidance on what would be the best option to execute this application ? Are there any other libraries in python I could use since I am not a java programmer ?

Thanks,
Sri

[pturmel]

To run python externally, you need no libraries locally. You need them wherever python will run.

In Ignition, I would use java’s normal classes (starting with ProcessBuilder) to spawn your platform’s ssh executable with suitable parameters (to connect to the remote system and launch your script), with a stream attached to the process’ stdout. Parse/decode that stream to get your result.

Use SSH keys to avoid any prompts while connecting. I recommend arranging for the selected key to only allow running the target script. (A limitation applied to the corresponding line of authorized_keys in the remote system.)

[Sri_Haran]

hi @pturmel can you give me any links for example.
Thanks
Sri

[pturmel]

I have no sample I can share, sorry. Look at the man-page for ssh and StackOverflow for ProcessBuilder.

[PGriffith]

ProcessBuilder sample:

Procedure for installing python libraries from source

Oh, right - system.util.execute is a ‘fire-and-forget’, it doesn’t give you access to standard output. Try adapting this: from java.lang import ProcessBuilder, String pb = ProcessBuilder([r"C:\Users\pgriffith\AppData\Local\Microsoft\WindowsApps\python3.exe", r"C:\Users\pgriffith\Downloads\test.py"]) process = pb.start() output = String(process.getInputStream().readAllBytes()) print output

[Sri_Haran]

Thanks @PGriffith,
That worked Fine for me
Regards,
Sri