Patch Paramiko channel.py to add channel logging (to debug SCP for example)

paramiko.channel.monkey-patch.py

import paramiko

def patch_paramiko():
  from paramiko.common import DEBUG
  recv_ori = paramiko.channel.Channel.recv
  send_ori = paramiko.channel.Channel.send
  exec_command_ori = paramiko.channel.Channel.exec_command

  def patched_exec_command(self, command):
    self._log(DEBUG, 'Executing command: {}'.format(command))
    return exec_command_ori(self, command)

  def patched_recv(self, nbytes):
    out = recv_ori(self, nbytes)
    self._log(DEBUG, 'recv: {}'.format(out))
    return out

  def patched_send(self, s, from_all=False):
    if not from_all:
      self._log(DEBUG, 'send: {}'.format(s if isinstance(s, bytes) else s.encode('utf-8')))
    return send_ori(self, s)

  def patched_sendall(self, s):
    self._log(DEBUG, 'sendall: {}'.format(s if isinstance(s, bytes) else s.encode('utf-8')))
    while s:
      sent = self.send(s, True)
      s = s[sent:]
    return None

  paramiko.channel.Channel.exec_command = patched_exec_command
  paramiko.channel.Channel.recv = patched_recv
  paramiko.channel.Channel.send = patched_send
  paramiko.channel.Channel.sendall = patched_sendall


import logging
logging.basicConfig(level=logging.DEBUG)
patch_paramiko()

paramiko.channel.py.diff

diff --git a/channel.py b/channel.patched.py
index 41b1895..2766b94 100644
--- a/channel.py
+++ b/channel.patched.py
@@ -187,6 +187,9 @@ class Channel(ClosingContextManager):
             `.SSHException` -- if the request was rejected or the channel was
             closed
         """
+        self._log(DEBUG, 'Requesting PTY (termtype={}, width={}, heigth={}, width_pixel={}, heigth_pixel={})'.format(
+            term, width, height, width_pixels, height_pixels
+        ))
         m = Message()
         m.add_byte(cMSG_CHANNEL_REQUEST)
         m.add_int(self.remote_chanid)
@@ -220,6 +223,7 @@ class Channel(ClosingContextManager):
             `.SSHException` -- if the request was rejected or the channel was
             closed
         """
+        self._log(DEBUG, 'Invoking shell')
         m = Message()
         m.add_byte(cMSG_CHANNEL_REQUEST)
         m.add_int(self.remote_chanid)
@@ -246,6 +250,7 @@ class Channel(ClosingContextManager):
             `.SSHException` -- if the request was rejected or the channel was
             closed
         """
+        self._log(DEBUG, 'Executing command: {}'.format(command))
         m = Message()
         m.add_byte(cMSG_CHANNEL_REQUEST)
         m.add_int(self.remote_chanid)
@@ -272,6 +277,7 @@ class Channel(ClosingContextManager):
             `.SSHException` -- if the request was rejected or the channel was
             closed
         """
+        self._log(DEBUG, 'Invoking subsystem: {}'.format(subsystem))
         m = Message()
         m.add_byte(cMSG_CHANNEL_REQUEST)
         m.add_int(self.remote_chanid)
@@ -297,6 +303,9 @@ class Channel(ClosingContextManager):
             `.SSHException` -- if the request was rejected or the channel was
             closed
         """
+        self._log(DEBUG, 'Resizing PTY (width={}, heigth={}, width_pixel={}, heigth_pixel={})'.format(
+            width, height, width_pixels, height_pixels
+        ))
         m = Message()
         m.add_byte(cMSG_CHANNEL_REQUEST)
         m.add_int(self.remote_chanid)
@@ -709,6 +718,7 @@ class Channel(ClosingContextManager):
             m.add_int(ack)
             self.transport._send_user_message(m)
 
+        self._log(DEBUG, 'recv: {}'.format(out))
         return out
 
     def recv_stderr_ready(self):
@@ -757,6 +767,7 @@ class Channel(ClosingContextManager):
             m.add_int(ack)
             self.transport._send_user_message(m)
 
+        self._log(DEBUG, 'recv stderr: {}'.format(out))
         return out
 
     def send_ready(self):
@@ -772,6 +783,7 @@ class Channel(ClosingContextManager):
             ``True`` if a `send` call on this channel would immediately succeed
             or fail
         """
+        self._log(DEBUG, 'send ready')
         self.lock.acquire()
         try:
             if self.closed or self.eof_sent:
@@ -795,6 +807,7 @@ class Channel(ClosingContextManager):
             by `settimeout`.
         """
 
+        self._log(DEBUG, 'send: {}'.format(s if isinstance(s, bytes) else s.encode('utf-8')))
         m = Message()
         m.add_byte(cMSG_CHANNEL_DATA)
         m.add_int(self.remote_chanid)
@@ -818,6 +831,7 @@ class Channel(ClosingContextManager):
         .. versionadded:: 1.1
         """
 
+        self._log(DEBUG, 'send stderr: {}'.format(s if isinstance(s, bytes) else s.encode('utf-8')))
         m = Message()
         m.add_byte(cMSG_CHANNEL_EXTENDED_DATA)
         m.add_int(self.remote_chanid)
@@ -842,6 +856,7 @@ class Channel(ClosingContextManager):
             sent, there is no way to determine how much data (if any) was sent.
             This is irritating, but identically follows Python's API.
         """
+        self._log(DEBUG, 'sendall: {}'.format(s if isinstance(s, bytes) else s.encode('utf-8')))
         while s:
             sent = self.send(s)
             s = s[sent:]
@@ -863,6 +878,7 @@ class Channel(ClosingContextManager):
 
         .. versionadded:: 1.1
         """
+        self._log(DEBUG, 'sendall stderr: {}'.format(s if isinstance(s, bytes) else s.encode('utf-8')))
         while s:
             sent = self.send_stderr(s)
             s = s[sent:]