Added new platyvenv Python script.

platypush/platyvenv/__init__.py

@@ -0,0 +1,196 @@
+"""
+Platyvenv is a helper script that allows you to automatically create a
+virtual environment for Platypush starting from a configuration file.
+"""
+
+import argparse
+import inspect
+import os
+import pathlib
+import re
+import subprocess
+import sys
+from typing import Sequence
+import venv
+
+from platypush.config import Config
+from platypush.utils import get_src_root
+from platypush.utils.manifest import (
+    Dependencies,
+    InstallContext,
+)
+
+
+# pylint: disable=too-few-public-methods
+class VenvBuilder:
+    """
+    Build a virtual environment from on a configuration file.
+
+    :param cfgfile: Path to the configuration file.
+    :param image: The base image to use.
+    """
+
+    def __init__(self, cfgfile: str, gitref: str, output_dir: str) -> None:
+        self.cfgfile = os.path.abspath(os.path.expanduser(cfgfile))
+        self.output_dir = os.path.abspath(os.path.expanduser(output_dir))
+        self.gitref = gitref
+
+    @property
+    def _pip_cmd(self) -> Sequence[str]:
+        """
+        :return: The pip install command to use for the selected environment.
+        """
+        return (
+            os.path.join(self.output_dir, 'bin', 'python'),
+            '-m',
+            'pip',
+            'install',
+            '-U',
+            '--no-cache-dir',
+            '--no-input',
+        )
+
+    def _install_system_packages(self, deps: Dependencies):
+        """
+        Install the required system packages.
+        """
+        for cmd in deps.to_pkg_install_commands():
+            print(f'Installing system packages: {cmd}')
+            subprocess.call(re.split(r'\s+', cmd.strip()))
+
+    def _prepare_venv(self) -> None:
+        """
+        Installs the virtual environment under the configured output_dir.
+        """
+        print(f'Creating virtual environment under {self.output_dir}...')
+
+        venv.create(
+            self.output_dir,
+            symlinks=True,
+            with_pip=True,
+            upgrade_deps=True,
+        )
+
+        print(
+            f'Installing base Python dependencies under {self.output_dir}...',
+        )
+
+        subprocess.call([*self._pip_cmd, 'pip'])
+        pwd = os.getcwd()
+
+        try:
+            os.chdir(os.path.dirname(get_src_root()))
+            subprocess.call([*self._pip_cmd, '.'])
+        finally:
+            os.chdir(pwd)
+
+    def _install_extra_pip_packages(self, deps: Dependencies):
+        """
+        Install the extra pip dependencies parsed through the
+        """
+        pip_deps = list(deps.to_pip_install_commands(full_command=False))
+        if not pip_deps:
+            return
+
+        print(
+            f'Installing extra pip dependencies under {self.output_dir}: '
+            + ' '.join(pip_deps)
+        )
+
+        subprocess.call([*self._pip_cmd, *pip_deps])
+
+    def build(self):
+        """
+        Build a Dockerfile based on a configuration file.
+        """
+        Config.init(self.cfgfile)
+
+        deps = Dependencies.from_config(
+            self.cfgfile,
+            install_context=InstallContext.VENV,
+        )
+
+        self._install_system_packages(deps)
+        self._prepare_venv()
+        self._install_extra_pip_packages(deps)
+
+    @classmethod
+    def from_cmdline(cls, args: Sequence[str]) -> 'VenvBuilder':
+        """
+        Create a DockerfileGenerator instance from command line arguments.
+
+        :param args: Command line arguments.
+        :return: A DockerfileGenerator instance.
+        """
+        parser = argparse.ArgumentParser(
+            prog='platyvenv',
+            add_help=False,
+            description='Create a Platypush virtual environment from a config.yaml.',
+        )
+
+        parser.add_argument(
+            '-h', '--help', dest='show_usage', action='store_true', help='Show usage'
+        )
+
+        parser.add_argument(
+            'cfgfile',
+            type=str,
+            nargs='?',
+            help='The path to the configuration file. If not specified a minimal '
+            'virtual environment only with the base dependencies will be '
+            'generated.',
+        )
+
+        parser.add_argument(
+            '-o',
+            '--output',
+            dest='output_dir',
+            type=str,
+            required=False,
+            default='venv',
+            help='Target directory for the virtual environment (default: ./venv)',
+        )
+
+        parser.add_argument(
+            '--ref',
+            '-r',
+            dest='gitref',
+            required=False,
+            type=str,
+            default='master',
+            help='If platyvenv is not run from a Platypush installation directory, '
+            'it will clone the sources via git. You can specify through this '
+            'option which branch, tag or commit hash to use. Defaults to master.',
+        )
+
+        opts, _ = parser.parse_known_args(args)
+        if opts.show_usage:
+            parser.print_help()
+            sys.exit(0)
+
+        if not opts.cfgfile:
+            opts.cfgfile = os.path.join(
+                str(pathlib.Path(inspect.getfile(Config)).parent),
+                'config.auto.yaml',
+            )
+
+            print(
+                f'No configuration file specified. Using {opts.cfgfile}.',
+                file=sys.stderr,
+            )
+
+        return cls(opts.cfgfile, gitref=opts.gitref, output_dir=opts.output_dir)
+
+
+def main():
+    """
+    Generates a virtual environment based on the configuration file.
+    """
+    VenvBuilder.from_cmdline(sys.argv[1:]).build()
+
+
+if __name__ == '__main__':
+    sys.exit(main())
+
+
+# vim:sw=4:ts=4:et:

platypush/platyvenv/__main__.py

@@ -0,0 +1,5 @@
+from platypush.platyvenv import main
+
+main()
+
+# vim:sw=4:ts=4:et: