lorry: Use common method to create working git repositories

Add an ensure_gitdir method, that creates a bare git repository if the
given directory doesn't yet exist.  It also logs what happened and
returns a flag for whether it created the directory.

Use this to replace the open-coded versions of this in (most) gitify
functions.

Add a comment in prepare_working_repos explaining why we can't just
call it there.

1 files changed, 17 insertions, 14 deletions

diff --git a/lorry b/lorry
index 4044e6d..e37261c 100755
--- a/lorry
+++ b/lorry
@@ -471,6 +471,8 @@ class Lorry(cliapp.Application):
                 shutil.rmtree(temp_repo)
 
         if active_count == 0:
+            # We can't create the repo here because "git cvsimport"
+            # and "git svn init" insist on doing so themselves
             return temp_repo, None, 1
 
         self.copy_gitdir(active_repo, temp_repo)
@@ -481,6 +483,17 @@ class Lorry(cliapp.Application):
         with open(count_name, 'w') as count_file:
             count_file.write('%d\n' % count)
 
+    def ensure_gitdir(self, gitdir):
+        # Create git directory if it doesn't exist.  Return flag for
+        # whether we created it.
+        exists = os.path.exists(gitdir)
+        if not exists:
+            self.progress('.. creating git repo')
+            self.run_program(['git', 'init', '--bare', gitdir])
+        else:
+            self.progress('.. updating existing clone')
+        return not exists
+
     def copy_gitdir(self, source, dest):
         if not os.path.exists(source):
             return None
@@ -516,10 +529,7 @@ class Lorry(cliapp.Application):
             env = dict(os.environ)
             env['GIT_SSL_NO_VERIFY'] = 'true'
 
-        if not os.path.exists(gitdir):
-            self.progress('.. initialising git dir')
-            self.run_program(['git', 'init', '--bare', gitdir])
-        self.progress('.. updating existing clone')
+        self.ensure_gitdir(gitdir)
         argv = ['git', '-c', 'gc.autodetach=false', 'fetch', '--prune',
                 spec['url'], '+refs/heads/*:refs/heads/*',
                 '+refs/tags/*:refs/tags/*']
@@ -538,11 +548,7 @@ class Lorry(cliapp.Application):
             self.progress('.. creating bzr repository')
             self.run_program([bzr, 'init-repo', '--no-trees', bzrdir])
 
-        if not os.path.exists(gitdir):
-            self.progress('.. creating git repo')
-            os.mkdir(gitdir)
-            self.run_program(['git', 'init', '--bare', gitdir])
-            self.needs_aggressive = True
+        self.needs_aggressive = self.ensure_gitdir(gitdir)
 
         # branches are the listed branches, plus the branch specified in url
         if 'branches' in spec:
@@ -692,9 +698,7 @@ class Lorry(cliapp.Application):
             self.run_program(['hg', 'clone', '--quiet', *cert_options,
                               spec['url'], hgdir])
 
-        if not os.path.exists(gitdir):
-            self.needs_aggressive = True
-            self.run_program(['git', 'init', '--bare', gitdir])
+        self.needs_aggressive = self.ensure_gitdir(gitdir)
 
         # Since there are marks files in existing deployments that
         # have broken references, fix up the marks file before rather
@@ -737,8 +741,7 @@ class Lorry(cliapp.Application):
         else:
             self.progress('.. no need to run, nothing to do')
             return
-        if not os.path.exists(gitdir):
-            self.run_program(['git', 'init', '--bare', gitdir])
+        self.ensure_gitdir(gitdir)
 
         cmdline = ["%s.%s-importer" % (lorry_path, archive_type), archive_dest]
         self.run_program(cmdline, cwd=gitdir)