Resolves issue with vmware_dvs_host module for v2.0

When this module was written back in May 2015 we were using 1.9.x. Being lazy I added to param the objects that the other functions would need. What I have noticed is in 2.0 exit_json is trying to jsonify those complex objects and failing. This PR resolves that issue with the vmware_dvs_host module.

@kamsz reported this issue in https://github.com/ansible/ansible-modules-extras/pull/1568

Playbook
```
- name: Add Host to dVS
      local_action:
        module: vmware_dvs_host
        hostname: "{{ mgmt_ip_address }}"
        username: "{{ vcsa_user }}"
        password: "{{ vcsa_pass }}"
        esxi_hostname: "{{ hostvars[item].hostname }}"
        switch_name: dvSwitch
        vmnics: "{{ dvs_vmnic }}"
        state: present
      with_items: groups['foundation_esxi']
```
Module Testing
```
TASK [Add Host to dVS] *********************************************************
task path: /opt/autodeploy/projects/emmet/site_deploy.yml:234
ESTABLISH LOCAL CONNECTION FOR USER: root
localhost EXEC ( umask 22 && mkdir -p "$( echo $HOME/.ansible/tmp/ansible-tmp-1454694039.6-259977654985844 )" && echo "$( echo $HOME/.ansible/tmp/ansible-tmp-1454694039.6-259977654985844 )" )
localhost PUT /tmp/tmpGrHqbd TO /root/.ansible/tmp/ansible-tmp-1454694039.6-259977654985844/vmware_dvs_host
localhost EXEC LANG=en_US.UTF-8 LC_ALL=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 /usr/bin/python /root/.ansible/tmp/ansible-tmp-1454694039.6-259977654985844/vmware_dvs_host; rm -rf "/root/.ansible/tmp/ansible-tmp-1454694039.6-259977654985844/" > /dev/null 2>&1
localhost EXEC ( umask 22 && mkdir -p "$( echo $HOME/.ansible/tmp/ansible-tmp-1454694058.76-121920794239796 )" && echo "$( echo $HOME/.ansible/tmp/ansible-tmp-1454694058.76-121920794239796 )" )
localhost PUT /tmp/tmpkP7DPu TO /root/.ansible/tmp/ansible-tmp-1454694058.76-121920794239796/vmware_dvs_host
localhost EXEC LANG=en_US.UTF-8 LC_ALL=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 /usr/bin/python /root/.ansible/tmp/ansible-tmp-1454694058.76-121920794239796/vmware_dvs_host; rm -rf "/root/.ansible/tmp/ansible-tmp-1454694058.76-121920794239796/" > /dev/null 2>&1
localhost EXEC ( umask 22 && mkdir -p "$( echo $HOME/.ansible/tmp/ansible-tmp-1454694090.2-33641188152663 )" && echo "$( echo $HOME/.ansible/tmp/ansible-tmp-1454694090.2-33641188152663 )" )
localhost PUT /tmp/tmp216NwV TO /root/.ansible/tmp/ansible-tmp-1454694090.2-33641188152663/vmware_dvs_host
localhost EXEC LANG=en_US.UTF-8 LC_ALL=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 /usr/bin/python /root/.ansible/tmp/ansible-tmp-1454694090.2-33641188152663/vmware_dvs_host; rm -rf "/root/.ansible/tmp/ansible-tmp-1454694090.2-33641188152663/" > /dev/null 2>&1
changed: [foundation-vcsa -> localhost] => (item=foundation-esxi-01) => {"changed": true, "invocation": {"module_args": {"esxi_hostname": "cscesxtmp001", "hostname": "172.27.0.100", "password": "VALUE_SPECIFIED_IN_NO_LOG_PARAMETER", "state": "present", "switch_name": "dvSwitch", "username": "root", "vmnics": ["vmnic2"]}, "module_name": "vmware_dvs_host"}, "item": "foundation-esxi-01", "result": "None"}
changed: [foundation-vcsa -> localhost] => (item=foundation-esxi-02) => {"changed": true, "invocation": {"module_args": {"esxi_hostname": "cscesxtmp002", "hostname": "172.27.0.100", "password": "VALUE_SPECIFIED_IN_NO_LOG_PARAMETER", "state": "present", "switch_name": "dvSwitch", "username": "root", "vmnics": ["vmnic2"]}, "module_name": "vmware_dvs_host"}, "item": "foundation-esxi-02", "result": "None"}
changed: [foundation-vcsa -> localhost] => (item=foundation-esxi-03) => {"changed": true, "invocation": {"module_args": {"esxi_hostname": "cscesxtmp003", "hostname": "172.27.0.100", "password": "VALUE_SPECIFIED_IN_NO_LOG_PARAMETER", "state": "present", "switch_name": "dvSwitch", "username": "root", "vmnics": ["vmnic2"]}, "module_name": "vmware_dvs_host"}, "item": "foundation-esxi-03", "result": "None"}
```

cloud/vmware/vmware_dvs_host.py

@@ -76,151 +76,151 @@ except ImportError:
     HAS_PYVMOMI = False
 
 
-def find_dvspg_by_name(dv_switch, portgroup_name):
-    portgroups = dv_switch.portgroup
+class VMwareDvsHost(object):
+    def __init__(self, module):
+        self.module = module
+        self.dv_switch = None
+        self.uplink_portgroup = None
+        self.host = None
+        self.dv_switch = None
+        self.nic = None
+        self.content = connect_to_api(self.module)
+        self.state = self.module.params['state']
+        self.switch_name = self.module.params['switch_name']
+        self.esxi_hostname = self.module.params['esxi_hostname']
+        self.vmnics = self.module.params['vmnics']
+
+    def process_state(self):
+        try:
+            dvs_host_states = {
+                'absent': {
+                    'present': self.state_destroy_dvs_host,
+                    'absent': self.state_exit_unchanged,
+                },
+                'present': {
+                    'update': self.state_update_dvs_host,
+                    'present': self.state_exit_unchanged,
+                    'absent': self.state_create_dvs_host,
+                }
+            }
+
+            dvs_host_states[self.state][self.check_dvs_host_state()]()
+        except vmodl.RuntimeFault as runtime_fault:
+            self.module.fail_json(msg=runtime_fault.msg)
+        except vmodl.MethodFault as method_fault:
+            self.module.fail_json(msg=method_fault.msg)
+        except Exception as e:
+            self.module.fail_json(msg=str(e))
+
+    def find_dvspg_by_name(self):
+        portgroups = self.dv_switch.portgroup
 
         for pg in portgroups:
-        if pg.name == portgroup_name:
+            if pg.name == self.portgroup_name:
                 return pg
-
         return None
 
-
-def find_dvs_uplink_pg(dv_switch):
+    def find_dvs_uplink_pg(self):
         # There should only always be a single uplink port group on
         # a distributed virtual switch
 
-    if len(dv_switch.config.uplinkPortgroup):
-        return dv_switch.config.uplinkPortgroup[0]
+        if len(self.dv_switch.config.uplinkPortgroup):
+            return self.dv_switch.config.uplinkPortgroup[0]
         else:
             return None
 
-
-# operation should be edit, add and remove
-def modify_dvs_host(dv_switch, host, operation, uplink_portgroup=None, vmnics=None):
-
+    # operation should be edit, add and remove
+    def modify_dvs_host(self, operation):
         spec = vim.DistributedVirtualSwitch.ConfigSpec()
-
-    spec.configVersion = dv_switch.config.configVersion
+        spec.configVersion = self.dv_switch.config.configVersion
         spec.host = [vim.dvs.HostMember.ConfigSpec()]
         spec.host[0].operation = operation
-    spec.host[0].host = host
+        spec.host[0].host = self.host
 
         if operation in ("edit", "add"):
             spec.host[0].backing = vim.dvs.HostMember.PnicBacking()
             count = 0
 
-        for nic in vmnics:
+            for nic in self.vmnics:
                 spec.host[0].backing.pnicSpec.append(vim.dvs.HostMember.PnicSpec())
                 spec.host[0].backing.pnicSpec[count].pnicDevice = nic
-            spec.host[0].backing.pnicSpec[count].uplinkPortgroupKey = uplink_portgroup.key
+                spec.host[0].backing.pnicSpec[count].uplinkPortgroupKey = self.uplink_portgroup.key
                 count += 1
 
-    task = dv_switch.ReconfigureDvs_Task(spec)
+        task = self.dv_switch.ReconfigureDvs_Task(spec)
         changed, result = wait_for_task(task)
         return changed, result
 
-
-def state_destroy_dvs_host(module):
-
+    def state_destroy_dvs_host(self):
         operation = "remove"
-    host = module.params['host']
-    dv_switch = module.params['dv_switch']
-
         changed = True
         result = None
 
-    if not module.check_mode:
-        changed, result = modify_dvs_host(dv_switch, host, operation)
-    module.exit_json(changed=changed, result=str(result))
-
+        if not self.module.check_mode:
+            changed, result = self.modify_dvs_host(operation)
+        self.module.exit_json(changed=changed, result=str(result))
 
-def state_exit_unchanged(module):
-    module.exit_json(changed=False)
+    def state_exit_unchanged(self):
+        self.module.exit_json(changed=False)
 
-
-def state_update_dvs_host(module):
-    dv_switch = module.params['dv_switch']
-    uplink_portgroup = module.params['uplink_portgroup']
-    vmnics = module.params['vmnics']
-    host = module.params['host']
+    def state_update_dvs_host(self):
         operation = "edit"
         changed = True
         result = None
 
-    if not module.check_mode:
-        changed, result = modify_dvs_host(dv_switch, host, operation, uplink_portgroup, vmnics)
-    module.exit_json(changed=changed, result=str(result))
-
+        if not self.module.check_mode:
+            changed, result = self.modify_dvs_host(operation)
+        self.module.exit_json(changed=changed, result=str(result))
 
-def state_create_dvs_host(module):
-    dv_switch = module.params['dv_switch']
-    uplink_portgroup = module.params['uplink_portgroup']
-    vmnics = module.params['vmnics']
-    host = module.params['host']
+    def state_create_dvs_host(self):
         operation = "add"
         changed = True
         result = None
 
-    if not module.check_mode:
-        changed, result = modify_dvs_host(dv_switch, host, operation, uplink_portgroup, vmnics)
-    module.exit_json(changed=changed, result=str(result))
-
+        if not self.module.check_mode:
+            changed, result = self.modify_dvs_host(operation)
+        self.module.exit_json(changed=changed, result=str(result))
 
-def find_host_attached_dvs(esxi_hostname, dv_switch):
-    for dvs_host_member in dv_switch.config.host:
-        if dvs_host_member.config.host.name == esxi_hostname:
+    def find_host_attached_dvs(self):
+        for dvs_host_member in self.dv_switch.config.host:
+            if dvs_host_member.config.host.name == self.esxi_hostname:
                 return dvs_host_member.config.host
 
         return None
 
-
-def check_uplinks(dv_switch, host, vmnics):
+    def check_uplinks(self):
         pnic_device = []
 
-    for dvs_host_member in dv_switch.config.host:
-        if dvs_host_member.config.host == host:
+        for dvs_host_member in self.dv_switch.config.host:
+            if dvs_host_member.config.host == self.host:
                 for pnicSpec in dvs_host_member.config.backing.pnicSpec:
                     pnic_device.append(pnicSpec.pnicDevice)
 
-    return collections.Counter(pnic_device) == collections.Counter(vmnics)
-
-
-def check_dvs_host_state(module):
+        return collections.Counter(pnic_device) == collections.Counter(self.vmnics)
 
-    switch_name = module.params['switch_name']
-    esxi_hostname = module.params['esxi_hostname']
-    vmnics = module.params['vmnics']
+    def check_dvs_host_state(self):
+        self.dv_switch = find_dvs_by_name(self.content, self.switch_name)
 
-    content = connect_to_api(module)
-    module.params['content'] = content
+        if self.dv_switch is None:
+            raise Exception("A distributed virtual switch %s does not exist" % self.switch_name)
 
-    dv_switch = find_dvs_by_name(content, switch_name)
+        self.uplink_portgroup = self.find_dvs_uplink_pg()
 
-    if dv_switch is None:
-        raise Exception("A distributed virtual switch %s does not exist" % switch_name)
+        if self.uplink_portgroup is None:
+            raise Exception("An uplink portgroup does not exist on the distributed virtual switch %s"
+                            % self.switch_name)
 
-    uplink_portgroup = find_dvs_uplink_pg(dv_switch)
+        self.host = self.find_host_attached_dvs()
 
-    if uplink_portgroup is None:
-        raise Exception("An uplink portgroup does not exist on the distributed virtual switch %s" % switch_name)
-
-    module.params['dv_switch'] = dv_switch
-    module.params['uplink_portgroup'] = uplink_portgroup
-
-    host = find_host_attached_dvs(esxi_hostname, dv_switch)
-
-    if host is None:
+        if self.host is None:
             # We still need the HostSystem object to add the host
             # to the distributed vswitch
-        host = find_hostsystem_by_name(content, esxi_hostname)
-        if host is None:
-            module.fail_json(msg="The esxi_hostname %s does not exist in vCenter" % esxi_hostname)
-        module.params['host'] = host
+            self.host = find_hostsystem_by_name(self.content, self.esxi_hostname)
+            if self.host is None:
+                self.module.fail_json(msg="The esxi_hostname %s does not exist in vCenter" % self.esxi_hostname)
             return 'absent'
         else:
-        module.params['host'] = host
-        if check_uplinks(dv_switch, host, vmnics):
+            if self.check_uplinks():
                 return 'present'
             else:
                 return 'update'
@@ -239,27 +239,8 @@ def main():
     if not HAS_PYVMOMI:
         module.fail_json(msg='pyvmomi is required for this module')
 
-    try:
-
-        dvs_host_states = {
-            'absent': {
-                'present': state_destroy_dvs_host,
-                'absent': state_exit_unchanged,
-            },
-            'present': {
-                'update': state_update_dvs_host,
-                'present': state_exit_unchanged,
-                'absent': state_create_dvs_host,
-            }
-        }
-
-        dvs_host_states[module.params['state']][check_dvs_host_state(module)](module)
-    except vmodl.RuntimeFault as runtime_fault:
-        module.fail_json(msg=runtime_fault.msg)
-    except vmodl.MethodFault as method_fault:
-        module.fail_json(msg=method_fault.msg)
-    except Exception as e:
-        module.fail_json(msg=str(e))
+    vmware_dvs_host = VMwareDvsHost(module)
+    vmware_dvs_host.process_state()
 
 from ansible.module_utils.vmware import *
 from ansible.module_utils.basic import *