replace console entry points with just importing the module

importing pkg_resources and looking up entry points wastes 100ms+
of time, which is totally unnecessary

This is based on
QubesOS/qubes-core-admin-client@b731ef3885
by @qubesuser

setup.py

@@ -4,18 +4,42 @@
 import os
 
 import setuptools
+import setuptools.command.install
 
 
 # don't import: import * is unreliable and there is no need, since this is
 # compile time and we have source files
 def get_console_scripts():
+    yield 'qrexec-policy', 'qubespolicy.cli'
+    yield 'qrexec-policy-agent', 'qubespolicy.agent'
+    yield 'qrexec-policy-graph', 'qubespolicy.graph'
     for filename in os.listdir('./qubes/tools'):
         basename, ext = os.path.splitext(os.path.basename(filename))
         if basename == '__init__' or ext != '.py':
             continue
-        yield '{} = qubes.tools.{}:main'.format(
-            basename.replace('_', '-'), basename)
+        yield basename.replace('_', '-'), 'qubes.tools.{}'.format(basename)
 
+# create simple scripts that run much faster than "console entry points"
+class CustomInstall(setuptools.command.install.install):
+    def run(self):
+        bin = os.path.join(self.root, "usr/bin")
+        try:
+            os.makedirs(bin)
+        except:
+            pass
+        for file, pkg in get_console_scripts():
+           path = os.path.join(bin, file)
+           with open(path, "w") as f:
+               f.write(
+"""#!/usr/bin/python3
+from {} import main
+import sys
+if __name__ == '__main__':
+	sys.exit(main())
+""".format(pkg))
+
+           os.chmod(path, 0o755)
+        setuptools.command.install.install.run(self)
 
 if __name__ == '__main__':
     setuptools.setup(
@@ -30,12 +54,10 @@ if __name__ == '__main__':
         package_data = {
             'qubespolicy': ['glade/*.glade'],
         },
+        cmdclass={
+            'install': CustomInstall,
+        },
         entry_points={
-            'console_scripts': list(get_console_scripts()) + [
-                'qrexec-policy = qubespolicy.cli:main',
-                'qrexec-policy-agent = qubespolicy.agent:main',
-                'qrexec-policy-graph = qubespolicy.graph:main',
-            ],
             'qubes.vm': [
                 'AppVM = qubes.vm.appvm:AppVM',
                 'TemplateVM = qubes.vm.templatevm:TemplateVM',