Docker debugging docs

Dockerfile

@@ -43,15 +43,13 @@ ARG DEBIAN_FRONTEND=noninteractive
 RUN apt-get update && apt-get install -y --no-install-recommends python3 \
         # To generate certificates
         openssl \
-        # Required for the setup.py install
+        # Required for the setup.py install and progressbar (required by pyrdp-convert)
         python3-distutils \
         # GUI and notifications stuff
         libgl1-mesa-glx libxcb-xinerama0 \
         notify-osd dbus-x11 libxkbcommon-x11-0 \
         # Runtime requirement for PyAV (pyrdp-convert to MP4)
         libavcodec58 libavdevice58 \
-        # Runtime requirement by progressbar (required by pyrdp-convert)
-        python3-distutils \
         && rm -rf /var/lib/apt/lists/*
 
 # Copy preinstalled dependencies from compile image

docs/debugging-recipes.adoc

@@ -0,0 +1,40 @@
+= Debugging recipes
+
+== Debugging from the docker container
+
+Build the container (or use an existing tag):
+
+    docker build -t pyrdp -f Dockerfile .
+
+Run it interactive to get a shell but specify root user (to be able to run `pip install`):
+
+    docker run -ti -v $PWD:/home/pyrdp/ --user root pyrdp bash
+
+In the container, install pip:
+
+    apt update
+    apt install python3-pip
+
+Now move away from `/home/pyrdp/` to avoid loading order conflicts and activate the `venv`:
+
+    cd /
+    source /opt/venv/bin/activate
+
+Install the debugger:
+
+    pip install ipdb
+
+Run pyrdp, for example:
+
+    ipdb3 /opt/venv/bin/pyrdp-convert.py -f mp4 /home/pyrdp/rdp_replay_20210112_16-14-08_535_Elizabeth685320.pyrdp
+
+Run `c` to continue on loading breakpoint:
+
+```
+> /opt/venv/bin/pyrdp-convert.py(3)<module>()
+      2 # EASY-INSTALL-SCRIPT: 'pyrdp==1.1.1.dev0','pyrdp-convert.py'
+----> 3 __requires__ = 'pyrdp==1.1.1.dev0'
+      4 __import__('pkg_resources').run_script('pyrdp==1.1.1.dev0', 'pyrdp-convert.py')
+
+ipdb> c
+```