Git: Determine if remote URL is being changed (#4243)

* Git: Determine if remote URL is being changed

Ansible reported there were no changes when only the remote URL for a
repo was changed. This properly tracks and reports when the remote URL
for a repo changes.

Fixes #4006

* Fix handling of local repo paths

* Git: Use newer method for fetching remote URL

* Git: use ls-remote to fetch remote URL

Using ls-remote to fetch remote URL is supported in earlier versions
of Git compared to using remote command.

* Maintain previous behavior for older Git versions

Previously whether or not the remote URL changed was not factored
into command's changed status. Git versions prior to 1.7.5 lack the
functionality used for fetching a repo's remote URL so these versions
will update the remote URL without affecting the changed status.

lib/ansible/modules/source_control/git.py

@@ -206,6 +206,7 @@ EXAMPLES = '''
 
 import re
 import tempfile
+from ansible.utils.path import unfrackpath
 from distutils.version import LooseVersion
 
 def get_submodule_update_params(module, git_path, cwd):
@@ -521,15 +522,33 @@ def get_head_branch(git_path, module, dest, remote, bare=False):
     f.close()
     return branch
 
-def set_remote_url(git_path, module, repo, dest, remote):
+def get_remote_url(git_path, module, dest, remote):
-    ''' updates repo from remote sources '''
+    '''Return URL of remote source for repo.'''
-    commands = [("set a new url %s for %s" % (repo, remote), [git_path, 'remote', 'set-url', remote, repo])]
+    command = [git_path, 'ls-remote', '--get-url', remote]
-
-    for (label,command) in commands:
     (rc, out, err) = module.run_command(command, cwd=dest)
     if rc != 0:
+        # There was an issue getting remote URL, most likely
+        # command is not available in this version of Git.
+        return None
+    return out.rstrip('\n')
+
+def set_remote_url(git_path, module, repo, dest, remote):
+    ''' updates repo from remote sources '''
+    # Return if remote URL isn't changing.
+    remote_url = get_remote_url(git_path, module, dest, remote)
+    if remote_url == repo or remote_url == unfrackpath(repo):
+        return False
+
+    command = [git_path, 'remote', 'set-url', remote, repo]
+    (rc, out, err) = module.run_command(command, cwd=dest)
+    if rc != 0:
+        label = "set a new url %s for %s" % (repo, remote)
         module.fail_json(msg="Failed to %s: %s %s" % (label, out, err))
 
+    # Return False if remote_url is None to maintain previous bevhavior
+    # for Git versions prior to 1.7.5 that lack required functionality.
+    return remote_url is not None
+
 def fetch(git_path, module, repo, dest, version, remote, depth, bare, refspec):
     ''' updates repo from remote sources '''
     set_remote_url(git_path, module, repo, dest, remote)
@@ -859,7 +878,14 @@ def main():
                 reset(git_path, module, dest)
 
         # exit if already at desired sha version
-        set_remote_url(git_path, module, repo, dest, remote)
+        if module.check_mode:
+            remote_url = get_remote_url(git_path, module, dest, remote)
+            remote_url_changed = remote_url and remote_url != repo and remote_url != unfrackpath(repo)
+        else:
+            remote_url_changed = set_remote_url(git_path, module, repo, dest, remote)
+        if remote_url_changed:
+            result.update(remote_url_changed=True)
+
         remote_head = get_remote_head(git_path, module, dest, version, remote, bare)
         if result['before'] == remote_head:
             if local_mods:
@@ -908,8 +934,6 @@ def main():
         if module.check_mode:
             if submodules_updated:
                 result.update(changed=True, after=remote_head)
-            else:
-                result.update(changed=False, after=remote_head)
                 module.exit_json(**result)
 
         if submodules_updated:
@@ -920,7 +944,7 @@ def main():
     result['after'] = get_version(module, git_path, dest)
 
     result.update(changed=False)
-    if result['before'] != result['after'] or local_mods or submodules_updated:
+    if result['before'] != result['after'] or local_mods or submodules_updated or remote_url_changed:
         result.update(changed=True)
         if module._diff:
             diff = get_diff(module, git_path, dest, repo, remote, depth, bare, result['before'], result['after'])