Enable to set ssh key from os enviroment (#126)

README.rst

@@ -20,9 +20,14 @@ that means SSH server must be running there already.
 
     h = Host("10.11.12.13")
     h.users.append(RootUser('123456'))
+
+    # Use with ssh key. export HOST_SSH_KEY to use specific ssh key, default is ~/.ssh/id_rsa
+    host.executor_factory = rrmngmnt.ssh.RemoteExecutorFactory(use_pkey=True)
+
     exec = h.executor()
     print exec.run_cmd(['echo', 'Hello World'])
 
+
 Features
 --------
 

rrmngmnt/ssh.py

@@ -61,7 +61,9 @@ def __init__(self, executor, timeout=None):
             self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
             if self._executor.use_pkey:
                 self.pkey = paramiko.RSAKey.from_private_key_file(
-                    ID_RSA_PRV % os.path.expanduser('~')
+                    os.getenv(
+                        "HOST_SSH_KEY", ID_RSA_PRV % os.path.expanduser('~')
+                    )
                 )
                 self._executor.user.password = None
             else: