Add GitDirectory class

3 files changed, 198 insertions, 0 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index 6b2a1cd7..787ee269 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -59,6 +59,7 @@ import cachekeycomputer
 import extractedtarball
 import fsutils
 import git
+import gitdir
 import localartifactcache
 import localrepocache
 import mountableimage
diff --git a/morphlib/gitdir.py b/morphlib/gitdir.py
new file mode 100644
index 00000000..2bf74437
--- /dev/null
+++ b/morphlib/gitdir.py
@@ -0,0 +1,131 @@
+# Copyright (C) 2013  Codethink Limited
+#
+# 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; version 2 of the License.
+#
+# 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.
+#
+# =*= License: GPL-2 =*=
+
+
+import cliapp
+
+import morphlib
+
+
+class GitDirectory(object):
+
+    '''Represent a git working tree + .git directory.
+
+    This class represents a directory that is the result of a
+    "git clone". It includes both the .git subdirectory and
+    the working tree. It is a thin abstraction, meant to make
+    it easier to do certain git operations.
+
+    '''
+
+    def __init__(self, dirname):
+        self.dirname = dirname
+
+    def _runcmd(self, argv, **kwargs):
+        '''Run a command at the root of the git directory.
+
+        See cliapp.runcmd for arguments.
+
+        Do NOT use this from outside the class. Add more public
+        methods for specific git operations instead.
+
+        '''
+
+        return cliapp.runcmd(argv, cwd=self.dirname, **kwargs)
+
+    def checkout(self, branch_name): # pragma: no cover
+        '''Check out a git branch.'''
+        self._runcmd(['git', 'checkout', branch_name])
+
+    def branch(self, new_branch_name, base_ref): # pragma: no cover
+        '''Create a git branch based on an existing ref.
+
+        This does not automatically check out the branch.
+
+        base_ref may be None, in which case the current branch is used.
+
+        '''
+
+        argv = ['git', 'branch', new_branch_name]
+        if base_ref is not None:
+            argv.append(base_ref)
+        self._runcmd(argv)
+
+    def update_remotes(self): # pragma: no cover
+        '''Update remotes.'''
+        self._runcmd(['git', 'remote', 'update', '--prune'])
+
+    def update_submodules(self, app): # pragma: no cover
+        '''Change .gitmodules URLs, and checkout submodules.'''
+        morphlib.git.update_submodules(app, self.dirname)
+
+    def set_config(self, key, value):
+        '''Set a git repository configuration variable.
+
+        The key must have at least one period in it: foo.bar for example,
+        not just foo. The part before the first period is interpreted
+        by git as a section name.
+
+        '''
+
+        self._runcmd(['git', 'config', key, value])
+
+    def get_config(self, key):
+        '''Return value for a git repository configuration variable.'''
+
+        value = self._runcmd(['git', 'config', key])
+        return value.strip()
+
+    def set_remote_fetch_url(self, remote_name, url):
+        '''Set the fetch URL for a remote.'''
+        self._runcmd(['git', 'remote', 'set-url', remote_name, url])
+
+    def get_remote_fetch_url(self, remote_name):
+        '''Return the fetch URL for a given remote.'''
+        output = self._runcmd(['git', 'remote', '-v'])
+        for line in output.splitlines():
+            words = line.split()
+            if (len(words) == 3 and
+                words[0] == remote_name and
+                words[2] == '(fetch)'):
+                return words[1]
+        return None
+
+    def update_remotes(self): # pragma: no cover
+        '''Run "git remote update --prune".'''
+        self._runcmd(['git', 'remote', 'update', '--prune'])
+
+
+def init(dirname):
+    '''Initialise a new git repository.'''
+
+    gd = GitDirectory(dirname)
+    gd._runcmd(['git', 'init'])
+    return gd
+
+
+def clone_from_cached_repo(cached_repo, dirname, ref): # pragma: no cover
+    '''Clone a CachedRepo into the desired directory.
+
+    The given ref is checked out (or git's default branch is checked out
+    if ref is None).
+
+    '''
+
+    cached_repo.clone_checkout(ref, dirname)
+    return GitDirectory(dirname)
+
diff --git a/morphlib/gitdir_tests.py b/morphlib/gitdir_tests.py
new file mode 100644
index 00000000..2494981a
--- /dev/null
+++ b/morphlib/gitdir_tests.py
@@ -0,0 +1,66 @@
+# Copyright (C) 2013  Codethink Limited
+#
+# 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; version 2 of the License.
+#
+# 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.
+#
+# =*= License: GPL-2 =*=
+
+
+import os
+import shutil
+import tempfile
+import unittest
+
+import morphlib
+
+
+class GitDirectoryTests(unittest.TestCase):
+
+    def setUp(self):
+        self.tempdir = tempfile.mkdtemp()
+        self.dirname = os.path.join(self.tempdir, 'foo')
+
+    def tearDown(self):
+        shutil.rmtree(self.tempdir)
+
+    def fake_git_clone(self):
+        os.mkdir(self.dirname)
+        os.mkdir(os.path.join(self.dirname, '.git'))
+
+    def test_has_dirname_attribute(self):
+        self.fake_git_clone()
+        gitdir = morphlib.gitdir.GitDirectory(self.dirname)
+        self.assertEqual(gitdir.dirname, self.dirname)
+
+    def test_runs_command_in_right_directory(self):
+        self.fake_git_clone()
+        gitdir = morphlib.gitdir.GitDirectory(self.dirname)
+        output = gitdir._runcmd(['pwd'])
+        self.assertEqual(output.strip(), self.dirname)
+
+    def test_sets_and_gets_configuration(self):
+        os.mkdir(self.dirname)
+        gitdir = morphlib.gitdir.init(self.dirname)
+        gitdir.set_config('foo.bar', 'yoyo')
+        self.assertEqual(gitdir.get_config('foo.bar'), 'yoyo')
+
+    def test_sets_remote(self):
+        os.mkdir(self.dirname)
+        gitdir = morphlib.gitdir.init(self.dirname)
+        self.assertEqual(gitdir.get_remote_fetch_url('origin'), None)
+
+        gitdir._runcmd(['git', 'remote', 'add', 'origin', 'foobar'])
+        url = 'git://git.example.com/foo'
+        gitdir.set_remote_fetch_url('origin', url)
+        self.assertEqual(gitdir.get_remote_fetch_url('origin'), url)
+