standardize ssh auth

we need to be following defautl paramiko rules,
first use pkey, then key_filenames (autodetecting ~/.ssh/ keys),
then password

We have too much boilerplate redudant code everywhere, we need
to standardize on a factory function that takes a node dict.

Using Python3 ChainMap we can layer overrides and defaults.

VNF descriptors have to default key_filename, password to Python None.
The only way to do this is to omit key values if the variable is not
defined, this way the dict will not have the value and it will
default to Python None

Add python2 chainmap backport

Updated unittest mocking to use ssh.SSH.from_node

Change-Id: I80b0cb606e593b33e317c9e5e8ed0b74da591514
Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>

1 files changed, 24 insertions, 2 deletions

diff --git a/yardstick/ssh.py b/yardstick/ssh.py
index cfbc3ca96..cf9adf0dc 100644
--- a/yardstick/ssh.py
+++ b/yardstick/ssh.py
@@ -70,13 +70,15 @@ import time
 import re
 
 import logging
+
 import paramiko
+from chainmap import ChainMap
 from oslo_utils import encodeutils
 from scp import SCPClient
 import six
 
 
-DEFAULT_PORT = 22
+SSH_PORT = paramiko.config.SSH_PORT
 
 
 class SSHError(Exception):
@@ -90,7 +92,7 @@ class SSHTimeout(SSHError):
 class SSH(object):
     """Represent ssh connection."""
 
-    def __init__(self, user, host, port=DEFAULT_PORT, pkey=None,
+    def __init__(self, user, host, port=SSH_PORT, pkey=None,
                  key_filename=None, password=None, name=None):
         """Initialize SSH client.
 
@@ -109,6 +111,9 @@ class SSH(object):
 
         self.user = user
         self.host = host
+        # everybody wants to debug this in the caller, do it here instead
+        self.log.debug("user:%s host:%s", user, host)
+
         # we may get text port from YAML, convert to int
         self.port = int(port)
         self.pkey = self._get_pkey(pkey) if pkey else None
@@ -123,6 +128,23 @@ class SSH(object):
         else:
             logging.getLogger("paramiko").setLevel(logging.WARN)
 
+    @classmethod
+    def from_node(cls, node, overrides=None, defaults=None):
+        if overrides is None:
+            overrides = {}
+        if defaults is None:
+            defaults = {}
+        params = ChainMap(overrides, node, defaults)
+        return cls(
+            user=params['user'],
+            host=params['ip'],
+            # paramiko doesn't like None default, requires SSH_PORT default
+            port=params.get('ssh_port', SSH_PORT),
+            pkey=params.get('pkey'),
+            key_filename=params.get('key_filename'),
+            password=params.get('password'),
+            name=params.get('name'))
+
     def _get_pkey(self, key):
         if isinstance(key, six.string_types):
             key = six.moves.StringIO(key)