Started the good, the bad and the ugly - code cleanup.

cdist/util/remoteutil.py

@@ -0,0 +1,50 @@
+# -*- coding: utf-8 -*-
+#
+# 2016 Darko Poljak (darko.poljak at gmail.com)
+#
+# This file is part of cdist.
+#
+# cdist 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, either version 3 of the License, or
+# (at your option) any later version.
+#
+# cdist 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 cdist. If not, see <http://www.gnu.org/licenses/>.
+#
+#
+
+
+def inspect_ssh_mux_opts():
+    """Inspect whether or not ssh supports multiplexing options.
+
+       Return string containing multiplexing options if supported.
+       If ControlPath is supported then placeholder for that path is
+       specified and can be used for final string formatting.
+       For example, this function can return string:
+       "-o ControlMaster=auto -o ControlPersist=125 -o ControlPath={}".
+       Then it can be formatted:
+       mux_opts_string.format('/tmp/tmpxxxxxx/ssh-control-path').
+    """
+    import subprocess
+
+    wanted_mux_opts = {
+        "ControlPath": "{}",
+        "ControlMaster": "auto",
+        "ControlPersist": "125",
+    }
+    mux_opts = " ".join([" -o {}={}".format(
+        x, wanted_mux_opts[x]) for x in wanted_mux_opts])
+    try:
+        subprocess.check_output("ssh {}".format(mux_opts),
+                                stderr=subprocess.STDOUT, shell=True)
+    except subprocess.CalledProcessError as e:
+        subproc_output = e.output.decode().lower()
+        if "bad configuration option" in subproc_output:
+            return ""
+    return mux_opts