Add --temp-dir to overcloud image build

By default, DIB puts the temp folders it uses in /tmp. In newer
versions, this can cause images to go missing because systemd will
cleanup tmp (see tmpfiles.d) which may cause files and directories in
the image to missing. This change adds a --temp-dir option to the cli
which by default will configure TMPDIR to be the current working
directory if not specified.

Change-Id: Ib5f82a175266675d9639416dd664604bee370a1d
Closes-Bug: #1879766
(cherry picked from commit 4c7df58d9b)

tripleoclient/v1/overcloud_image.py

@@ -82,6 +82,13 @@ class BuildOvercloudImage(command.Command):
             help=_("Output directory for images. Defaults to $TRIPLEO_ROOT,"
                    "or current directory if unset."),
         )
+        parser.add_argument(
+            "--temp-dir",
+            dest="temp_dir",
+            default=os.environ.get('TMPDIR', os.getcwd()),
+            help=_("Temporary directory to use when building the images. "
+                   "Defaults to $TMPDIR or current directory if unset."),
+        )
         return parser
 
     def take_action(self, parsed_args):
@@ -90,6 +97,7 @@ class BuildOvercloudImage(command.Command):
         if not parsed_args.config_files:
             parsed_args.config_files = [os.path.join(self.IMAGE_YAML_PATH, f)
                                         for f in self.DEFAULT_YAML]
+        os.environ.update({'TMPDIR': parsed_args.temp_dir})
         manager = build.ImageBuildManager(
             parsed_args.config_files,
             output_directory=parsed_args.output_directory,