Update external docs

external/source/HACKING.md

@@ -185,13 +185,42 @@ git submodules:
 Refer to the [testing README](test/README.md) for details on running the Cockpit
 integration tests locally.
 
-## Testing the Python bridge
+## Python bridge
 
-Cockpit currently has an experimental replacement for `cockpit-bridge`
-written in Python. It resides in `src/cockpit` with most of its rules in
-`src/Makefile.am`. This directory was chosen because it matches the standard
-so-called "src layout" convention for Python packages, where each package
-(`cockpit`) is a subdirectory of the `src` directory.
+Most distro releases now ship a replacement for the C bridge written in Python.
+It resides in `src/cockpit` with most of its rules in `src/Makefile.am`. This
+directory was chosen because it matches the standard so-called "src layout"
+convention for Python packages, where each package (`cockpit`) is a
+subdirectory of the `src` directory.
+
+### Running the bridge
+
+The Python bridge can be used interactively on a local machine:
+
+ PYTHONPATH=src python3 -m cockpit.bridge
+
+To make it easy to test out channels without having to write out messages
+manually, `cockpit.misc.print` can be used:
+
+ PYTHONPATH=src python3 -m cockpit.misc.print open fslist1 path=/etc watch=False | PYTHONPATH=src python3 -m cockpit.bridge
+
+These shell aliases might be useful when experimenting with the protocol:
+
+ alias cpy='PYTHONPATH=src python3 -m cockpit.bridge'
+ alias cpf='PYTHONPATH=src python3 -m cockpit.misc.print'
+
+When working with the Python bridge on test images, note that `RHEL/CentOS 8`,
+`debian-stable`, and `ubuntu-2204` still use the C bridge. So if you want to
+explicitly have the Python bridge on those images use:
+
+ ./test/image-prepare --python
+
+To enable debug logging in journal on a test image, you can pass `--debug` to
+`image-prepare`. This will set `COCKPIT_DEBUG=all` to `/etc/environment`, if
+you are only interested channel debug messages change `all` to
+`cockpit.channel`.
+
+### Testing the Python bridge
 
 There are a growing number of Python `unittest` tests being written to test
 parts of the new bridge code. You can run these with `make pytest` or

external/source/test/README.md

@@ -160,8 +160,8 @@ You can set these environment variables to configure the test suite:
   "centos-8-stream"
   "debian-stable"
   "debian-testing"
-  "fedora-37"
   "fedora-38"
+  "fedora-39"
   "fedora-coreos"
   "fedora-testing"
   "rhel-8-9"