Clarify exception handling in net modules (#15507)

* Clarify exception handling in EOS

Also modify to EOS to standardize modules. It makes vimdiff a lot less angry

* Move IOS exception handling into Cli

* Move IOS-XR exception handling into Cli

* Move JUNOS exception handling into Cli

* Move NXOS exception handling into Cli

And reorganize to make it match the other modules

* Move OpenSwitch exception handling into Cli

More speculative restructuring here

lib/ansible/module_utils/openswitch.py

@@ -16,6 +16,7 @@
 # You should have received a copy of the GNU General Public License
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 #
+
 import re
 import time
 import json
@@ -29,22 +30,22 @@ try:
 except ImportError:
     HAS_OPS = False
 
-from ansible.module_utils.basic import AnsibleModule, env_fallback
-from ansible.module_utils.urls import fetch_url
-from ansible.module_utils.shell import Shell, HAS_PARAMIKO
+from ansible.module_utils.basic import AnsibleModule, env_fallback, get_exception
+from ansible.module_utils.shell import Shell, ShellError, HAS_PARAMIKO
 from ansible.module_utils.netcfg import parse
+from ansible.module_utils.urls import fetch_url
 
 NET_PASSWD_RE = re.compile(r"[\r\n]?password: $", re.I)
 
 NET_COMMON_ARGS = dict(
-    host=dict(),
+    host=dict(required=True),
     port=dict(type='int'),
     username=dict(fallback=(env_fallback, ['ANSIBLE_NET_USERNAME'])),
     password=dict(no_log=True, fallback=(env_fallback, ['ANSIBLE_NET_PASSWORD'])),
     ssh_keyfile=dict(fallback=(env_fallback, ['ANSIBLE_NET_SSH_KEYFILE']), type='path'),
-    use_ssl=dict(default=True, type='bool'),
     validate_certs=dict(default=True, type='bool'),
     transport=dict(default='ssh', choices=['ssh', 'cli', 'rest']),
+    use_ssl=dict(default=True, type='bool'),
     provider=dict(type='dict')
 )
 
@@ -159,12 +160,21 @@ class Cli(object):
         password = self.module.params['password']
         key_filename = self.module.params['ssh_keyfile']
 
-        self.shell = Shell()
-        self.shell.open(host, port=port, username=username, password=password,
-                key_filename=key_filename)
+        try:
+            self.shell = Shell()
+            self.shell.open(host, port=port, username=username, password=password, key_filename=key_filename)
+        except ShellError:
+            e = get_exception()
+            msg = 'failed to connect to %s:%s - %s' % (host, port, str(e))
+            self.module.fail_json(msg=msg)
+
+    def send(self, commands, encoding='text'):
+        try:
+            return self.shell.send(commands)
+        except ShellError:
+            e = get_exception()
+            self.module.fail_json(msg=e.message, commands=commands)
 
-    def send(self, commands):
-        return self.shell.send(commands)
 
 class NetworkModule(AnsibleModule):
 
@@ -185,38 +195,37 @@ class NetworkModule(AnsibleModule):
         super(NetworkModule, self)._load_params()
         provider = self.params.get('provider') or dict()
         for key, value in provider.items():
-            if key in NET_COMMON_ARGS.keys():
+            if key in NET_COMMON_ARGS:
                 if self.params.get(key) is None and value is not None:
                     self.params[key] = value
 
     def connect(self):
-        if self.params['transport'] == 'rest':
-            self.connection = Rest(self)
-        elif self.params['transport'] == 'cli':
-            self.connection = Cli(self)
+        cls = globals().get(str(self.params['transport']).capitalize())
+        try:
+            self.connection = cls(self)
+        except TypeError:
+            e = get_exception()
+            self.fail_json(msg=e.message)
 
         self.connection.connect()
 
-    def configure(self, config):
+    def configure(self, commands):
         if self.params['transport'] == 'cli':
-            commands = to_list(config)
+            commands = to_list(commands)
             commands.insert(0, 'configure terminal')
             responses = self.execute(commands)
             responses.pop(0)
             return responses
         elif self.params['transport'] == 'rest':
             path = '/system/full-configuration'
-            return self.connection.put(path, data=config)
+            return self.connection.put(path, data=commands)
         else:
             if not self._opsidl:
                 (self._extschema, self._opsidl) = get_opsidl()
-            ops.dc.write(config, self._extschema, self._opsidl)
+            ops.dc.write(commands, self._extschema, self._opsidl)
 
     def execute(self, commands, **kwargs):
-        try:
-            return self.connection.send(commands, **kwargs)
-        except Exception, exc:
-            self.fail_json(msg=exc.message, commands=commands)
+        return self.connection.send(commands, **kwargs)
 
     def disconnect(self):
         self.connection.close()
@@ -251,7 +260,6 @@ def get_module(**kwargs):
     if not HAS_OPS and module.params['transport'] == 'ssh':
         module.fail_json(msg='could not import ops library')
 
-    # HAS_PARAMIKO is set by module_utils/shell.py
     if module.params['transport'] == 'cli' and not HAS_PARAMIKO:
         module.fail_json(msg='paramiko is required but does not appear to be installed')
 
@@ -259,4 +267,3 @@ def get_module(**kwargs):
         module.connect()
 
     return module
-