Add support for bare git reference repos

This adds two parameters to the git module:

  bare (boolean)
    Indicates this is to be a bare repositori

  reference (string)
    Indicates the path or url to the reference repo.
    Check out the "--reference" option in the "git clone"
    man page

Added appropriate tests.

source_control/git

@@ -43,6 +43,12 @@ options:
             - What version of the repository to check out.  This can be the
               full 40-character I(SHA-1) hash, the literal string C(HEAD), a
               branch name, or a tag name.
+    reference:
+        required: false
+        default: null
+        version_added: "1.4"
+        description:
+            - Reference repository (see "git clone --reference ...")
     remote:
         required: false
         default: "origin"
@@ -81,6 +87,14 @@ options:
         description:
             - Path to git executable to use. If not supplied,
               the normal mechanism for resolving binary paths will be used.
+    bare:
+        required: false
+        default: "no"
+        choices: [ "yes", "no" ]
+        version_added: "1.4"
+        description:
+            - if C(yes), repository will be created as a bare repo, otherwise
+              it will be a standard repo with a workspace.
 notes:
     - If the task seems to be hanging, first verify remote host is in C(known_hosts).
       SSH will prompt user to authorize the first contact with a remote host. One solution is to add
@@ -105,15 +119,14 @@ EXAMPLES = '''
 import re
 import tempfile
 
-def get_version(git_path, dest):
+def get_version(git_path, dest, ref="HEAD"):
     ''' samples the version of the git repo '''
     os.chdir(dest)
-    cmd = "%s show" % (git_path,)
+    cmd = "%s rev-parse %s" % (git_path, ref)
-    sha = os.popen(cmd).read().split("\n")
+    sha = os.popen(cmd).read().rstrip("\n")
-    sha = sha[0].split()[1]
     return sha
 
-def clone(git_path, module, repo, dest, remote, depth, version):
+def clone(git_path, module, repo, dest, remote, depth, version, bare, reference):
     ''' makes a new git repo if it does not already exist '''
     dest_dirname = os.path.dirname(dest)
     try:
@@ -121,16 +134,28 @@ def clone(git_path, module, repo, dest, remote, depth, version):
     except:
         pass
     os.chdir(dest_dirname)
-    cmd = [ git_path, 'clone', '-o', remote, '--recursive' ]
+    cmd = [ git_path, 'clone' ]
-    if is_remote_branch(git_path, module, dest, repo, version) \
+    if bare:
-    or is_remote_tag(git_path, module, dest, repo, version):
+        cmd.append('--bare')
-        cmd.extend([ '--branch', version ])
+    else:
+        cmd.extend([ '--origin', remote, '--recursive' ])
+        if is_remote_branch(git_path, module, dest, repo, version) \
+        or is_remote_tag(git_path, module, dest, repo, version):
+            cmd.extend([ '--branch', version ])
     if depth:
         cmd.extend([ '--depth', str(depth) ])
+    if reference:
+        cmd.extend([ '--reference', str(reference) ])
     cmd.extend([ repo, dest ])
-    return module.run_command(cmd, check_rc=True)
+    module.run_command(cmd, check_rc=True)
-
+    if bare:
-def has_local_mods(git_path, dest):
+        os.chdir(dest)
+        if remote != 'origin':
+            module.run_command([git_path, 'remote', 'add', remote, repo], check_rc=True)
+  
+def has_local_mods(git_path, dest, bare):
+    if bare:
+        return False
     os.chdir(dest)
     cmd = "%s status -s" % (git_path,)
     lines = os.popen(cmd).read().splitlines()
@@ -147,7 +172,7 @@ def reset(git_path, module, dest):
     cmd = "%s reset --hard HEAD" % (git_path,)
     return module.run_command(cmd, check_rc=True)
 
-def get_remote_head(git_path, module, dest, version, remote):
+def get_remote_head(git_path, module, dest, version, remote, bare):
     cloning = False
     if remote == module.params['repo']:
         cloning = True
@@ -158,7 +183,7 @@ def get_remote_head(git_path, module, dest, version, remote):
             # cloning the repo, just get the remote's HEAD version
             cmd = '%s ls-remote %s -h HEAD' % (git_path, remote)
         else:
-            head_branch = get_head_branch(git_path, module, dest, remote)
+            head_branch = get_head_branch(git_path, module, dest, remote, bare)
             cmd = '%s ls-remote %s -h refs/heads/%s' % (git_path, remote, head_branch)
     elif is_remote_branch(git_path, module, dest, remote, version):
         cmd = '%s ls-remote %s -h refs/heads/%s' % (git_path, remote, version)
@@ -218,7 +243,7 @@ def is_not_a_branch(git_path, module, dest):
             return True
     return False
 
-def get_head_branch(git_path, module, dest, remote):
+def get_head_branch(git_path, module, dest, remote, bare=False):
     '''
     Determine what branch HEAD is associated with.  This is partly
     taken from lib/ansible/utils/__init__.py.  It finds the correct
@@ -226,7 +251,10 @@ def get_head_branch(git_path, module, dest, remote):
     associated with.  In the case of a detached HEAD, this will look
     up the branch in .git/refs/remotes/<remote>/HEAD.
     '''
-    repo_path = os.path.join(dest, '.git')
+    if bare:
+        repo_path = dest
+    else:
+        repo_path = os.path.join(dest, '.git')
     # Check if the .git is a file. If it is a file, it means that we are in a submodule structure.
     if os.path.isfile(repo_path):
         try:
@@ -249,14 +277,20 @@ def get_head_branch(git_path, module, dest, remote):
     f.close()
     return branch
 
-def fetch(git_path, module, repo, dest, version, remote):
+def fetch(git_path, module, repo, dest, version, remote, bare):
     ''' updates repo from remote sources '''
     os.chdir(dest)
-    (rc, out1, err1) = module.run_command("%s fetch %s" % (git_path, remote))
+    if bare:
+        (rc, out1, err1) = module.run_command([git_path, 'fetch', remote, '+refs/heads/*:refs/heads/*'])
+    else:
+        (rc, out1, err1) = module.run_command("%s fetch %s" % (git_path, remote))
     if rc != 0:
         module.fail_json(msg="Failed to download remote objects and refs")
 
-    (rc, out2, err2) = module.run_command("%s fetch --tags %s" % (git_path, remote))
+    if bare:
+        (rc, out2, err2) = module.run_command([git_path, 'fetch', remote, '+refs/tags/*:refs/tags/*'])
+    else:
+        (rc, out2, err2) = module.run_command("%s fetch --tags %s" % (git_path, remote))
     if rc != 0:
         module.fail_json(msg="Failed to download remote objects and refs")
     (rc, out3, err3) = submodule_update(git_path, module, dest)
@@ -315,24 +349,31 @@ def main():
             repo=dict(required=True, aliases=['name']),
             version=dict(default='HEAD'),
             remote=dict(default='origin'),
+            reference=dict(default=None),
             force=dict(default='yes', type='bool'),
             depth=dict(default=None, type='int'),
             update=dict(default='yes', type='bool'),
             executable=dict(default=None),
+            bare=dict(default='no', type='bool'),
         ),
         supports_check_mode=True
     )
 
-    dest    = os.path.abspath(os.path.expanduser(module.params['dest']))
+    dest      = os.path.abspath(os.path.expanduser(module.params['dest']))
-    repo    = module.params['repo']
+    repo      = module.params['repo']
-    version = module.params['version']
+    version   = module.params['version']
-    remote  = module.params['remote']
+    remote    = module.params['remote']
-    force   = module.params['force']
+    force     = module.params['force']
-    depth   = module.params['depth']
+    depth     = module.params['depth']
-    update  = module.params['update']
+    update    = module.params['update']
-    git_path = module.params['executable'] or module.get_bin_path('git', True)
+    bare      = module.params['bare']
+    reference = module.params['reference']
+    git_path  = module.params['executable'] or module.get_bin_path('git', True)
 
-    gitconfig = os.path.join(dest, '.git', 'config')
+    if bare:
+        gitconfig = os.path.join(dest, 'config')
+    else:
+        gitconfig = os.path.join(dest, '.git', 'config')
 
     rc, out, err, status = (0, None, None, None)
 
@@ -344,7 +385,7 @@ def main():
         if module.check_mode:
             remote_head = get_remote_head(git_path, module, dest, version, repo)
             module.exit_json(changed=True, before=before, after=remote_head)
-        clone(git_path, module, repo, dest, remote, depth, version)
+        clone(git_path, module, repo, dest, remote, depth, version, bare, reference)
     elif not update:
         # Just return having found a repo already in the dest path
         # this does no checking that the repo is the actual repo
@@ -353,9 +394,8 @@ def main():
         module.exit_json(changed=False, before=before, after=before)
     else:
         # else do a pull
-        local_mods = has_local_mods(git_path, dest)
+        local_mods = has_local_mods(git_path, dest, bare)
         before = get_version(git_path, dest)
-        remote_head = get_remote_head(git_path, module, dest, version, remote)
         if local_mods:
             # failure should happen regardless of check mode
             if not force:
@@ -364,6 +404,7 @@ def main():
             if not module.check_mode:
                 reset(git_path, module, dest)
         # exit if already at desired sha version
+        remote_head = get_remote_head(git_path, module, dest, version, remote, bare)
         if before == remote_head:
             if local_mods:
                 module.exit_json(changed=True, before=before, after=remote_head,
@@ -372,11 +413,12 @@ def main():
                 module.exit_json(changed=False, before=before, after=remote_head)
         if module.check_mode:
             module.exit_json(changed=True, before=before, after=remote_head)
-        fetch(git_path, module, repo, dest, version, remote)
+        fetch(git_path, module, repo, dest, version, remote, bare)
 
     # switch to version specified regardless of whether
     # we cloned or pulled
-    switch_version(git_path, module, dest, remote, version)
+    if not bare:
+        switch_version(git_path, module, dest, remote, version)
 
     # determine if we changed anything
     after = get_version(git_path, dest)