Update installation instructions and run the installation test unconditionally

The installation instructions were based on running `setup.py` directly.
However, my understanding is that Python best practices have moved away
from doing that and towards using `pip` to install packages in a virtual
environment, and using a file like `requirements.txt` to pin dependency
versions.

This patch documents that updated installation procedure and runs the
installation process as a test unconditionally.

Fixes #68

Author: ldionne

docs/developer_guide.rst

@@ -10,8 +10,8 @@ started.
 Installation
 ------------
 
-See :ref:`quickstart` for setting up an installation. Use the "develop" option
-when running ~/lnt/setup.py.
+See :ref:`quickstart` for setting up an installation. Pass ``-e`` to ``pip`` when
+installing the package to install it in "editable" mode.
 
 Running LNT's Regression Tests
 ------------------------------

docs/quickstart.rst

@@ -12,35 +12,24 @@ Installation
 The first thing to do is to checkout install the LNT software itself. The
 following steps should suffice on any modern Unix variant:
 
-#. Install ``virtualenv``, if necessary::
-
-           sudo easy_install virtualenv
-
-   ``virtualenv`` is a standard Python tool for allowing the installation of
-   Python applications into their own sandboxes, or virtual environments.
-
-#. Create a new virtual environment for the LNT application::
-
-            virtualenv ~/mysandbox
-
-   This will create a new virtual environment at ``~/mysandbox``.
-
 #. Checkout the LNT sources::
 
             git clone https://github.com/llvm/llvm-lnt.git ~/lnt
 
+#. Create a new virtual environment for the LNT application and activate it::
+
+            python3 -m venv .venv
+            source .venv/bin/activate
+
 #. Install LNT into the virtual environment::
 
-           ~/mysandbox/bin/python ~/lnt/setup.py develop
+            pip install -r requirements.txt
 
-   We recommend using ``develop`` instead of install for local use, so that any
-   changes to the LNT sources are immediately propagated to your
-   installation. If you are running a production install or care a lot about
-   stability, you can use ``install`` which will copy in the sources and you
-   will need to explicitly re-install when you wish to update the LNT
-   application.
+Note that if you only want to use the client-side features of ``lnt``, you can
+install the requirements specified in ``requirements.client.txt`` instead, which
+are a bit more lightweight.
 
-That's it!
+That's it! ``lnt`` should now be accessible from the virtual environment.
 
 
 Running Tests

lnt/lnttool/main.py

@@ -475,8 +475,7 @@ def _version_check():
         installed = "{} {}".format(meta['Name'], meta['Version'])
         current = "{} {}".format(lnt.__name__, lnt.__version__)
         raise SystemExit(f"""\
-error: installed distribution {installed} is not current ({current}), you may need to reinstall
-LNT or rerun 'setup.py develop' if using development mode.""")
+error: installed distribution {installed} is not current ({current}), you may need to reinstall LNT""")
 
 
 def show_version(ctx, param, value):

requirements.client.txt

@@ -1 +1,17 @@
-.
+# These requirements are what you would install to run the client.
+# The client has fewer requirements than the server code.
+.
+aniso8601==1.2.0
+click==6.7
+Flask-RESTful==0.3.4
+Flask-WTF==0.12
+Flask==0.12.2
+itsdangerous==0.24
+Jinja2==2.11.3
+MarkupSafe==1.1.1
+python-gnupg==0.3.7
+pytz==2016.10
+SQLAlchemy==1.3.24
+Werkzeug==0.15.6
+WTForms==2.0.2
+pyyaml==5.1.2

requirements.server.txt

@@ -1,19 +1,6 @@
 # These requirements are what you would install on a production server.
+# The server has more requirements than the client.
 .
-aniso8601==1.2.0
-click==6.7
-Flask-RESTful==0.3.4
-Flask-WTF==0.12
-Flask==0.12.2
+-r requirements.client.txt
 gunicorn==19.9.0
-itsdangerous==0.24
-Jinja2==2.11.3
-MarkupSafe==1.1.1
-progressbar2
 psycopg2==2.9.10
-python-gnupg==0.3.7
-pytz==2016.10
-pyyaml==5.1.2
-SQLAlchemy==1.3.24
-Werkzeug==0.15.6
-WTForms==2.0.2

requirements.txt

@@ -1 +1 @@
--r requirements.server.txt
+-r requirements.server.txt

setup.py

@@ -14,12 +14,6 @@
     os.environ["CXX"] = "xcrun --sdk macosx clang"
     cflags += ['-stdlib=libc++', '-mmacosx-version-min=10.7']
 
-# setuptools expects to be invoked from within the directory of setup.py, but
-# it is nice to allow:
-#   python path/to/setup.py install
-# to work (for scripts, etc.)
-os.chdir(os.path.dirname(os.path.abspath(__file__)))
-
 cPerf = Extension('lnt.testing.profile.cPerf',
                   sources=['lnt/testing/profile/cPerf.cpp'],
                   extra_compile_args=['-std=c++11'] + cflags)

tests/utils/Installation.py

@@ -0,0 +1,8 @@
+# Check that installation using the client requirements works properly.
+#
+# RUN: rm -rf %t.venv
+# RUN: python -m venv %t.venv
+# RUN: cd %{src_root}
+# RUN: %t.venv/bin/python -m pip install -r requirements.client.txt
+# RUN: rm -rf %t.installation
+# RUN: %t.venv/bin/lnt create %t.installation

tests/utils/installation-client.shtest

@@ -0,0 +1,8 @@
+# Check that installation using the server requirements works properly.
+#
+# RUN: rm -rf %t.venv
+# RUN: python -m venv %t.venv
+# RUN: cd %{src_root}
+# RUN: %t.venv/bin/python -m pip install -r requirements.server.txt
+# RUN: rm -rf %t.installation
+# RUN: %t.venv/bin/lnt create %t.installation