Inspect and add by default ssh multiplexing options.

scripts/cdist

@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 #
 # 2010-2013 Nico Schottelius (nico-cdist at schottelius.org)
+# 2016 Darko Poljak (darko.poljak at gmail.com)
 #
 # This file is part of cdist.
 #
@@ -20,6 +21,32 @@
 #
 #
 
+def inspect_ssh_mux_opts():
+    """Inspect whether or not ssh supports multiplexing options"""
+    wanted_mux_opts = {
+        "ControlPath":"~/.ssh/master-%l-%r@%h:%p",
+        "ControlMaster":"auto",
+        "ControlPersist":"125",
+    }
+    # if checked key option is present then this assumes
+    # all options in value are present
+    check = {
+        "ControlMaster": ("ControlMaster", "ControlPath"),
+        "ControlPersist": ("ControlPersist",),
+    }
+    mux_opts = {}
+    for x in check:
+        try:
+            subprocess.check_output("ssh -o {}".format(x),
+                    stderr=subprocess.STDOUT)
+        except subprocess.CalledProcessError as e:
+            foo = e.output.decode().lower()
+            if not "bad configuration option" in foo:
+                for o in check[x]:
+                    mux_opts[o] = wanted_mux_opts[o]
+    foo = ["-o {}={}".format(x, mux_opts[x]) for x in mux_opts]
+    return " ".join(foo)
+
 def commandline():
     """Parse command line"""
     import argparse
@@ -53,6 +80,11 @@ def commandline():
     parser['banner'].set_defaults(func=cdist.banner.banner)
 
     # Config
+    # inspect multiplexing options for default remote copy/exec scp/ssh
+    MUX_OPTS = inspect_ssh_mux_opts()
+    cdist.REMOTE_EXEC += MUX_OPTS
+    cdist.REMOTE_COPY += MUX_OPTS
+
     parser['config'] = parser['sub'].add_parser('config',
         parents=[parser['loglevel']])
     parser['config'].add_argument('host', nargs='+',