Cisco NSO debug service python PyDev pydevd

This post presents  NSO python service debugging.

To debug you will need:

• PyDev plugin for eclipse
• pydevd python module

There two VMs configured in this case:

VM1: eclipse+pydev is installed

VM2: NSO+pydevd is installed (NSO service with pydevd initialized that is connecting to the Eclipse/PyDev Debugger.)

First configure NSO to increase the transaction timeout:

config t

java-vm service-transaction-timeout 12000

Second:

install eclipse and pydev in VM1:

• Link to install Eclipse https://www.eclipse.org/downloads/packages/installer
• Link to install the Pydev https://www.pydev.org/manual_101_install.html

install “pydevd” with pip/pip3 in VM2.

In VM1 Eclipse/PyDev has a debugger. To start the debugger you will need to perform the actions decribed below.

You have to open tab “Pydev”. To make visible tab Pydev you need to chose Pydev “Perspective”:

Window->Perspective->Open Perspective->Other->PyDev

Window->Perspective->Open Perspective->Other->Debug

Then you have to activate Debug Server( check the top of the window for tabs “File”,”Edit”, etc.:

PyDev->Start Debug Server

In the console you will find the next information:

Debug Server at port: 5678

So Pydevd from NSO service will connect to Eclipce PyDev Debugger via port [5678] and ip address of machine where Debug server is Running.

The last thing left is to initialize the pydevd python module in the service:

import pydevd

pydevd.settrace('10.0.10.100', port=5678, stdoutToServer=True, stderrToServer=True)

to apply the modification in the NSO you have to do

LINUX SHELL: /rfs/service_dmytro_shytyi_net/src/$ make clean all

NSO: package reload

NSO: dmytro_shytyi_net 1

NSO: commit

When the service will be activated the pydevd module will connect the Eclipse/PyDev Debugger.

The Eclipse/PyDev Debugger will open an window and propose to open a file with the code of the service saved locally in the VM1.
It should be the same as the file in the NSO VM2.

Open in the appeared window the python file located in the NSO service: “/rfs/service_dmytro_shytyi_net/python/dmytro_shytyi_net/dmytro_shytyi_net.py”

Now you may debug your service. This is free opensource analog to PyCharm (in the PyCharm commynity edition the remote debuggin is not available).

In the figure below you may see the value ” Hello from Dmytro” of the variable “helloworld” of the NSO service.