pyln-spec: Clean up the setup.py files

This centralizes the setup.py file, and parametrizes it so it can
auto-detect which bolt we are building. It also uses trick 3 from [1]
to avoid importing the package itself during the manifest creation,
which'd cause an import error due to missing dependencies.

[1] https://packaging.python.org/guides/single-sourcing-package-version/

Author: cdecker

contrib/pyln-spec/bolt1/setup.py

@@ -0,0 +1 @@
+../setup.py

contrib/pyln-spec/bolt1/setup.py

@@ -0,0 +1 @@
+../setup.py

contrib/pyln-spec/bolt2/setup.py

@@ -0,0 +1 @@
+../setup.py

contrib/pyln-spec/bolt2/setup.py

@@ -0,0 +1 @@
+../setup.py

contrib/pyln-spec/bolt4/setup.py

@@ -0,0 +1,53 @@
+from setuptools import setup
+import io
+import os
+
+base = os.path.dirname(__file__)
+with io.open(os.path.join(base, 'requirements.txt'), encoding='utf-8') as f:
+    requirements = [r for r in f.read().split('\n') if len(r)]
+
+
+def bolt_meta(bolt_num):
+    ctx = {}
+    pkg_dir = os.path.join(base, 'pyln', 'spec', 'bolt{}'.format(bolt_num))
+
+    files = ['gen_version.py', 'gen_csv_version.py', 'text.py']
+
+    for f in files:
+        f = os.path.join(pkg_dir, f)
+        with open(f, 'r') as fd:
+            exec(fd.read(), ctx)
+
+    __version__ = '{__base_version__}.{__csv_version__}.{__post_version__}'.format(**ctx)
+    return {
+        'description': ctx['desc'],
+        'version': __version__,
+    }
+
+
+def bolt_num():
+    """Look into the pyln/spec/ directory to see which subpackages we provide.
+    """
+    dirlist = os.listdir(os.path.join('pyln', 'spec'))
+    assert(len(dirlist) == 1)  # Should only be the boltX directory
+    b = dirlist[0]
+    assert(b[:4] == 'bolt')
+    return int(b[4])
+
+
+boltnum = bolt_num()
+meta = bolt_meta(boltnum)
+
+setup(
+    **meta,
+    name='pyln-bolt{}'.format(boltnum),
+    url='http://github.com/ElementsProject/lightning',
+    author='Rusty Russell',
+    author_email='[email protected]',
+    license='MIT',
+    packages=['pyln.spec.bolt{}'.format(boltnum)],
+    package_data={'pyln.proto.message': ['py.typed']},
+    scripts=[],
+    zip_safe=True,
+    install_requires=requirements
+)