Add schroot module.

ognibuild/schroot.py

@@ -0,0 +1,120 @@
+#!/usr/bin/python3
+# Copyright (C) 2020 Jelmer Vernooij <jelmer@jelmer.uk>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+import shlex
+import subprocess
+
+from typing import Optional, List, Dict
+
+
+class Session(object):
+
+    _cwd: Optional[str]
+    _location: Optional[str]
+    chroot: str
+
+    def __init__(self, chroot: str):
+        if not isinstance(chroot, str):
+            raise TypeError('not a valid chroot: %r' % chroot)
+        self.chroot = chroot
+        self._location = None
+        self._cwd = None
+
+    def _get_location(self) -> str:
+        return subprocess.check_output(
+            ['schroot', '--location', '-c', 'session:' + self.session_id
+             ]).strip().decode()
+
+    def _end_session(self) -> None:
+        subprocess.check_output(
+            ['schroot', '-c', 'session:' + self.session_id, '-e'])
+
+    def __enter__(self) -> 'Session':
+        self.session_id = subprocess.check_output(
+            ['schroot', '-c', self.chroot, '-b']).strip().decode()
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self._end_session()
+        return False
+
+    def chdir(self, cwd: str) -> None:
+        self._cwd = cwd
+
+    @property
+    def location(self) -> str:
+        if self._location is None:
+            self._location = self._get_location()
+        return self._location
+
+    def _run_argv(self, argv: List[str], cwd: Optional[str] = None,
+                  user: Optional[str] = None,
+                  env: Optional[Dict[str, str]] = None):
+        base_argv = ['schroot', '-r', '-c', 'session:' + self.session_id]
+        if cwd is None:
+            cwd = self._cwd
+        if cwd is not None:
+            base_argv.extend(['-d', cwd])
+        if user is not None:
+            base_argv.extend(['-u', user])
+        if env:
+            argv = [
+                'sh', '-c',
+                ' '.join(
+                    ['%s=%s ' % (key, shlex.quote(value))
+                     for (key, value) in env.items()] +
+                    [shlex.quote(arg) for arg in argv])]
+        return base_argv + ['--'] + argv
+
+    def check_call(
+            self,
+            argv: List[str], cwd: Optional[str] = None,
+            user: Optional[str] = None,
+            env: Optional[Dict[str, str]] = None):
+        try:
+            subprocess.check_call(self._run_argv(argv, cwd, user, env=env))
+        except subprocess.CalledProcessError as e:
+            raise subprocess.CalledProcessError(e.returncode, argv)
+
+    def check_output(
+            self,
+            argv: List[str], cwd: Optional[str] = None,
+            user: Optional[str] = None,
+            env: Optional[Dict[str, str]] = None) -> bytes:
+        try:
+            return subprocess.check_output(
+                self._run_argv(argv, cwd, user, env=env))
+        except subprocess.CalledProcessError as e:
+            raise subprocess.CalledProcessError(e.returncode, argv)
+
+    def Popen(self, argv, cwd: Optional[str] = None,
+              user: Optional[str] = None, **kwargs):
+        return subprocess.Popen(self._run_argv(argv, cwd, user), **kwargs)
+
+    def call(
+            self, argv: List[str], cwd: Optional[str] = None,
+            user: Optional[str] = None):
+        return subprocess.call(self._run_argv(argv, cwd, user))
+
+    def create_home(self) -> None:
+        """Create the user's home directory."""
+        home = self.check_output(
+            ['sh', '-c', 'echo $HOME']).decode().rstrip('\n')
+        user = self.check_output(
+            ['sh', '-c', 'echo $LOGNAME']).decode().rstrip('\n')
+        self.check_call(['mkdir', '-p', home], user='root')
+        self.check_call(['chown', user, home], user='root')