[PATCH v6 22/25] python: add Makefile for some common tasks

[John Snow]

Add "make venv" to create the pipenv-managed virtual environment that
contains our explicitly pinned dependencies.

Add "make check" to run the python linters [in the host execution
environment].

Add "make venv-check" which combines the above two: create/update the
venv, then run the linters in that explicitly managed environment.

Add "make develop" which canonizes the runes needed to get both the
linting pre-requisites (the "[devel]" part), and the editable
live-install (the "-e" part) of these python libraries.

make clean: delete miscellaneous python packaging output possibly
created by pipenv, pip, or other python packaging utilities

make distclean: delete the above, the .venv, and the editable "qemu"
package forwarder (qemu.egg-info) if there is one.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 python/README.rst |  3 +++
 python/Makefile   | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 python/Makefile

diff --git a/python/README.rst b/python/README.rst
index e107bd12a69..3e09d20c23c 100644
--- a/python/README.rst
+++ b/python/README.rst
@@ -35,6 +35,9 @@ Files in this directory
 - ``qemu/`` Python package source directory.
 - ``tests/`` Python package tests directory.
 - ``avocado.cfg`` Configuration for the Avocado test-runner.
+  Used by ``make check`` et al.
+- ``Makefile`` provides some common testing/installation invocations.
+  Try ``make help`` to see available targets.
 - ``MANIFEST.in`` is read by python setuptools, it specifies additional files
   that should be included by a source distribution.
 - ``PACKAGE.rst`` is used as the README file that is visible on PyPI.org.
diff --git a/python/Makefile b/python/Makefile
new file mode 100644
index 00000000000..184f59e5634
--- /dev/null
+++ b/python/Makefile
@@ -0,0 +1,42 @@
+.PHONY: help venv venv-check check clean distclean develop
+
+help:
+       @echo "python packaging help:"
+       @echo ""
+       @echo "make venv:       Create pipenv's virtual environment."
+       @echo "    NOTE: Requires Python 3.6 and pipenv."
+       @echo "          Will download packages from PyPI."
+       @echo "    Hint: (On Fedora): 'sudo dnf install python36 pipenv'"
+       @echo ""
+       @echo "make venv-check: run linters using pipenv's virtual environment."
+       @echo "    Hint: If you don't know which test to run, run this one!"
+       @echo ""
+       @echo "make develop:    Install deps for 'make check', and"
+       @echo "                 the qemu libs in editable/development mode."
+       @echo ""
+       @echo "make check:      run linters using the current environment."
+       @echo ""
+       @echo "make clean:      remove build output."
+       @echo ""
+       @echo "make distclean:  remove venv files, qemu package forwarder, and"
+       @echo "                 everything from 'make clean'."
+
+venv: .venv
+.venv: Pipfile.lock
+       @PIPENV_VENV_IN_PROJECT=1 pipenv sync --dev --keep-outdated
+       @touch .venv
+
+venv-check: venv
+       @pipenv run make check
+
+develop:
+       pip3 install -e .[devel]
+
+check:
+       @avocado --config avocado.cfg run tests/
+
+clean:
+       rm -rf build/ dist/
+
+distclean: clean
+       rm -rf qemu.egg-info/ .venv/
-- 
2.30.2