Add requirements files for install, test and plugin dependencies

Add `.in` and `.txt` requirements files for BuildStream's pure python
dependencies. For each pair, the `.in` file is supposed to capture the
loose version requirements, and the corresponding `.txt` file is
supposed to have frozen requirements. We have 3 such sets:

* `requirements`: BuildStream's runtime dependencies
* `dev-requirements`: Dependencies for running tests
* `plugin-requirements`: Dependencies for core plugins

Note that the frozen requirements files will only be used for testing
purposes, and `setup.py` will continue to read loose requirements.

1 files changed, 5 insertions, 18 deletions

diff --git a/setup.py b/setup.py
index 872e7da4e..ddcb03d6a 100755
--- a/setup.py
+++ b/setup.py
@@ -270,9 +270,12 @@ def get_cmdclass():
 #####################################################
 #               Gather requirements                 #
 #####################################################
-with open('dev-requirements.txt') as dev_reqs:
+with open('dev-requirements.in') as dev_reqs:
     dev_requires = dev_reqs.read().splitlines()
 
+with open('requirements.in') as install_reqs:
+    install_requires = install_reqs.read().splitlines()
+
 #####################################################
 #     Prepare package description from README       #
 #####################################################
@@ -334,23 +337,7 @@ setup(name='BuildStream',
               os.path.join('buildstream', 'data', 'bst')
           ])
       ],
-      install_requires=[
-          'setuptools',
-          'psutil',
-          # According to ruamel.yaml's PyPI page, we are suppose to use
-          # "<=0.15" in production until 0.15 becomes API stable.
-          # However we need ruamel.yaml 0.15.41 or greater for Python 3.7.
-          # We know that ruamel.yaml 0.15.52 breaks API in a way that
-          # is incompatible with BuildStream.
-          #
-          # See issues #571 and #790.
-          'ruamel.yaml >= 0.15.41, < 0.15.52',
-          'pluginbase',
-          'Click >= 7.0',
-          'jinja2 >= 2.10',
-          'protobuf >= 3.5',
-          'grpcio >= 1.10',
-      ],
+      install_requires=install_requires,
       entry_points=bst_install_entry_points,
       tests_require=dev_requires,
       zip_safe=False)