Enable paramiko to ask whether to add keys to known hosts.

lib/ansible/runner/__init__.py

@@ -53,7 +53,7 @@ multiprocessing_runner = None
 
 ################################################
 
-def _executor_hook(job_queue, result_queue):
+def _executor_hook(job_queue, result_queue, new_stdin):
 
     # attempt workaround of https://github.com/newsapps/beeswithmachineguns/issues/17
     # this function also not present in CentOS 6
@@ -64,7 +64,7 @@ def _executor_hook(job_queue, result_queue):
     while not job_queue.empty():
         try:
             host = job_queue.get(block=False)
-            return_data = multiprocessing_runner._executor(host)
+            return_data = multiprocessing_runner._executor(host, new_stdin)
             result_queue.put(return_data)
 
             if 'LEGACY_TEMPLATE_WARNING' in return_data.flags:
@@ -75,6 +75,8 @@ def _executor_hook(job_queue, result_queue):
             pass
         except:
             traceback.print_exc()
+    if new_stdin:
+        new_stdin.close()
 
 class HostVars(dict):
     ''' A special view of setup_cache that adds values from the inventory when needed. '''
@@ -133,6 +135,9 @@ class Runner(object):
         error_on_undefined_vars=C.DEFAULT_UNDEFINED_VAR_BEHAVIOR # ex. False
         ):
 
+        # used to lock multiprocess inputs that wish to share stdin
+        self.lockfile = tempfile.NamedTemporaryFile()
+
         if not complex_args:
             complex_args = {}
 
@@ -331,7 +336,7 @@ class Runner(object):
 
     # *****************************************************
 
-    def _executor(self, host):
+    def _executor(self, host, new_stdin):
         ''' handler for multiprocessing library '''
 
         def get_flags():
@@ -344,7 +349,9 @@ class Runner(object):
             return flags
 
         try:
-            exec_rc = self._executor_internal(host)
+            self._new_stdin = new_stdin
+
+            exec_rc = self._executor_internal(host, new_stdin)
             if type(exec_rc) != ReturnData:
                 raise Exception("unexpected return type: %s" % type(exec_rc))
             exec_rc.flags = get_flags()
@@ -363,7 +370,7 @@ class Runner(object):
 
     # *****************************************************
 
-    def _executor_internal(self, host):
+    def _executor_internal(self, host, new_stdin):
         ''' executes any module one or more times '''
 
         host_variables = self.inventory.get_variables(host)
@@ -774,8 +781,9 @@ class Runner(object):
 
         workers = []
         for i in range(self.forks):
+            new_stdin = os.fdopen(os.dup(sys.stdin.fileno()))
             prc = multiprocessing.Process(target=_executor_hook,
-                args=(job_queue, result_queue))
+                args=(job_queue, result_queue, new_stdin))
             prc.start()
             workers.append(prc)
 
@@ -847,7 +855,7 @@ class Runner(object):
             # We aren't iterating over all the hosts in this
             # group. So, just pick the first host in our group to
             # construct the conn object with.
-            result_data = self._executor(hosts[0]).result
+            result_data = self._executor(hosts[0], None).result
             # Create a ResultData item for each host in this group
             # using the returned result. If we didn't do this we would
             # get false reports of dark hosts.
@@ -865,7 +873,7 @@ class Runner(object):
                     raise errors.AnsibleError("interrupted")
                 raise
         else:
-            results = [ self._executor(h) for h in hosts ]
+            results = [ self._executor(h, None) for h in hosts ]
         return self._partition_results(results)
 
     # *****************************************************

lib/ansible/runner/connection_plugins/paramiko_ssh.py

@@ -15,6 +15,14 @@
 # You should have received a copy of the GNU General Public License
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 
+
+# ---
+# The paramiko transport is provided because many distributions, in particular EL6 and before
+# do not support ControlPersist in their SSH implementations.  This is needed on the Ansible
+# control machine to be reasonably efficient with connections.  Thus paramiko is faster
+# for most users on these platforms.  Users with ControlPersist capability can consider
+# using -c ssh or configuring the transport in ansible.cfg.
+
 import warnings
 import os
 import pipes
@@ -24,12 +32,19 @@ import logging
 import traceback
 import fcntl
 import sys
+from termios import tcflush, TCIFLUSH
 from binascii import hexlify
 from ansible.callbacks import vvv
 from ansible import errors
 from ansible import utils
 from ansible import constants as C
             
+AUTHENTICITY_MSG="""
+paramiko: The authenticity of host '%s' can't be established. 
+The %s key fingerprint is %s. 
+Are you sure you want to continue connecting (yes/no)?
+"""
+
 # prevent paramiko warning noise -- see http://stackoverflow.com/questions/3920502/
 HAVE_PARAMIKO=False
 with warnings.catch_warnings():
@@ -41,22 +56,49 @@ with warnings.catch_warnings():
     except ImportError:
         pass
 
-class MyAutoAddPolicy(object):
+class MyAddPolicy(object):
     """
-    Modified version of AutoAddPolicy in paramiko so we can determine when keys are added.
+    Based on AutoAddPolicy in paramiko so we can determine when keys are added
+    and also prompt for input.
 
     Policy for automatically adding the hostname and new host key to the
     local L{HostKeys} object, and saving it.  This is used by L{SSHClient}.
     """
 
+    def __init__(self, runner): 
+        self.runner = runner
+
     def missing_host_key(self, client, hostname, key):
 
+        if C.HOST_KEY_CHECKING:
+
+            KEY_LOCK = self.runner.lockfile
+            fcntl.lockf(KEY_LOCK, fcntl.LOCK_EX)
+ 
+            old_stdin = sys.stdin
+            sys.stdin = self.runner._new_stdin
+            fingerprint = hexlify(key.get_fingerprint())
+            ktype = key.get_name()
+            
+            # clear out any premature input on sys.stdin
+            tcflush(sys.stdin, TCIFLUSH)
+
+            inp = raw_input(AUTHENTICITY_MSG % (hostname, ktype, fingerprint))
+            sys.stdin = old_stdin
+            if inp not in ['yes','y','']:
+                fcntl.flock(KEY_LOCK, fcntl.LOCK_UN)
+                raise errors.AnsibleError("host connection rejected by user")
+
+            fcntl.flock(KEY_LOCK, fcntl.LOCK_UN)
+
+
         key._added_by_ansible_this_time = True
 
         # existing implementation below:
         client._host_keys.add(hostname, key.get_name(), key)
-        if client._host_keys_filename is not None:
-            client.save_host_keys(client._host_keys_filename)
+
+        # host keys are actually saved in close() function below
+        # in order to control ordering.
         
 
 # keep connection objects on a per host basis to avoid repeated attempts to reconnect
@@ -103,7 +145,7 @@ class Connection(object):
 
         if C.HOST_KEY_CHECKING:
             ssh.load_system_host_keys()
-        ssh.set_missing_host_key_policy(MyAutoAddPolicy())
+        ssh.set_missing_host_key_policy(MyAddPolicy(self.runner))
 
         allow_agent = True
         if self.password is not None: