Fixing ssh action to use private keys

* Password argument is optional now
 * Ability to pass private_key to use on executors
 * Modified std.ssh docs

Closes-Bug: #1502076

Change-Id: I1e92adabafada5e45355a0e3236e8965ec921f2f

doc/source/dsl/dsl_v2.rst

@@ -759,7 +759,8 @@ Input parameters:
 -  **host** - Host name that the command needs to be executed on.
    *Required*.
 -  **username** - User name to authenticate on the host.
--  **password** - User password to to authenticate on the host.
+-  **password** - User password to to authenticate on the host. *Optional.*
+-  **private_key** - Private key string which will be used for authentication on remote host. *Optional.*
 
 **NOTE**: Authentication using key pairs is supported, key should be
 on Mistral Executor server machine.

mistral/actions/std_actions.py

@@ -327,11 +327,12 @@ class SSHAction(base.Action):
     same order as provided hosts.
     """
 
-    def __init__(self, cmd, host, username, password):
+    def __init__(self, cmd, host, username, password=None, private_key=None):
         self.cmd = cmd
         self.host = host
         self.username = username
         self.password = password
+        self.private_key = private_key
 
     def run(self):
         def raise_exc(parent_exc=None):
@@ -352,7 +353,9 @@ class SSHAction(base.Action):
                     self.cmd,
                     host_name,
                     self.username,
-                    self.password)
+                    self.password,
+                    pkey=self.private_key
+                )
 
                 if status_code > 0:
                     return raise_exc()

mistral/tests/unit/utils/test_inspect_utils.py

@@ -15,6 +15,7 @@
 from mistral.actions import std_actions
 from mistral.tests import base
 from mistral.utils import inspect_utils as i_u
+from mistral.workflow import commands
 
 
 class InspectUtilsTest(base.BaseTest):
@@ -32,7 +33,7 @@ class InspectUtilsTest(base.BaseTest):
         self.assertEqual(http_action_params, parameters_str)
 
     def test_get_parameters_str_all_mandatory(self):
-        action_class = std_actions.SSHAction
-        parameters_str = i_u.get_arg_list_as_str(action_class.__init__)
+        clazz = commands.RunTask
+        parameters_str = i_u.get_arg_list_as_str(clazz.__init__)
 
-        self.assertEqual("cmd, host, username, password", parameters_str)
+        self.assertEqual("wf_ex, task_spec, ctx", parameters_str)

mistral/utils/ssh_utils.py

@@ -14,6 +14,8 @@
 #    See the License for the specific language governing permissions and
 #    limitations under the License.
 
+import six
+
 from oslo_log import log as logging
 import paramiko
 
@@ -31,11 +33,15 @@ def _read_paramimko_stream(recv_func):
     return result
 
 
-def _connect(host, username, password):
+def _connect(host, username, password, pkey):
+    if pkey:
+        pkey = paramiko.RSAKey(file_obj=six.StringIO(pkey))
+
     LOG.debug('Creating SSH connection to %s' % host)
     ssh = paramiko.SSHClient()
     ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
-    ssh.connect(host, username=username, password=password)
+    ssh.connect(host, username=username, password=password, pkey=pkey)
+
     return ssh
 
 
@@ -43,9 +49,9 @@ def _cleanup(ssh):
     ssh.close()
 
 
-def execute_command(cmd, host, username, password,
+def execute_command(cmd, host, username, password=None, pkey=None,
                     get_stderr=False, raise_when_error=True):
-    ssh = _connect(host, username, password)
+    ssh = _connect(host, username, password, pkey)
 
     LOG.debug("Executing command %s" % cmd)