Connecting to a remote IPython instance

Question

I would like to run an IPython instance on one machine and connect to it (over LAN) from a different process (to run some python commands). I understand that it is possible

Answer 1

If you just want to connect interactively, you can use SSH forwarding. I didn't find this documented anywhere on Stack Overflow yet, yet this question comes closest. This answer has been tested on Ipython 0.13. I got the information from this blog post.

1. Run ipython kernel on the remote machine:

   user@remote:~$ ipython3 kernel
   [IPKernelApp] To connect another client to this kernel, use:
   [IPKernelApp] --existing kernel-25333.json
   

2. Look at the kernel-25333.json file:

   user@remote:~$ cat ~/.ipython/profile_default/security/kernel-25333.json 
   {
     "stdin_port": 54985, 
     "ip": "127.0.0.1", 
     "hb_port": 50266, 
     "key": "da9c7ae2-02aa-47d4-8e67-e6153eb15366", 
     "shell_port": 50378, 
     "iopub_port": 49981
   }
   

3. Set up port-forwarding on the local machine:

   user@local:~$ ssh user@remote -f -N -L 54985:127.0.0.1:54985
   user@local:~$ ssh user@remote -f -N -L 50266:127.0.0.1:50266
   user@local:~$ ssh user@remote -f -N -L 50378:127.0.0.1:50378
   user@local:~$ ssh user@remote -f -N -L 49981:127.0.0.1:49981
   

4. Copy the kernel-25333.json file to the local machine:

   user@local:~$ rsync -av user@remote:.ipython/profile_default/security/kernel-25333.json ~/.ipython/profile_default/security/kernel-25333.json
   

5. Run ipython on the local machine using the new kernel:

   user@local:~$ ipython3 console --existing kernel-25333.json
   Python 3.2.3 (default, Oct 19 2012, 19:53:16)
   Type "copyright", "credits" or "license" for more information.
   
   IPython 0.13.1.rc2 -- An enhanced Interactive Python.
   ?         -> Introduction and overview of IPython's features.
   %quickref -> Quick reference.
   help      -> Python's own help system.
   object?   -> Details about 'object', use 'object??' for extra details.
   
   
   In [1]: import socket; print(socket.gethostname())
   remote