bigip_virtual_server – Manage LTM virtual servers on a BIG-IP

New in version 2.1.

Synopsis

  • Manage LTM virtual servers on a BIG-IP.

Parameters

Parameter Choices/Defaults Comments
address_translation
boolean
added in 2.6
    Choices:
  • no
  • yes
Specifies, when enabled, that the system translates the address of the virtual server.
When disabled, specifies that the system uses the address without translation.
This option is useful when the system is load balancing devices that have the same IP address.
When creating a new virtual server, the default is enabled.
clone_pools
list
added in 2.8
Specifies a pool or list of pools that the virtual server uses to replicate either client-side or server-side traffic.
Typically this option is used for intrusion detection.
context
string
    Choices:
  • clientside
  • serverside
The context option for a clone pool to replicate either client-side or server-side traffic.
pool_name
string / required
The pool name to which the server replicates the traffic.
Only pools created on Common partition or on the same partition as the virtual server can be used.
Referencing pool on common partition needs to be done in the full path format, for example, /Common/pool_name.
default_persistence_profile
string
Default Profile which manages the session persistence.
If you want to remove the existing default persistence profile, specify an empty value; "". See the documentation for an example.
When type is dhcp, this parameter will be ignored.
description
string
Virtual server description.
destination
string
Destination IP of the virtual server.
Required when state is present and virtual server does not exist.
When type is internal, this parameter is ignored. For all other types, it is required.
Destination can also be specified as a name for an existing Virtual Address.

aliases: address, ip
disabled_vlans
list
added in 2.5
List of VLANs to be disabled. If the partition is not specified in the VLAN, then the partition option of this module will be used.
This parameter is mutually exclusive with the enabled_vlans parameters.
enabled_vlans
list
added in 2.2
List of VLANs to be enabled. When a VLAN named all is used, all VLANs will be allowed. VLANs can be specified with or without the leading partition. If the partition is not specified in the VLAN, then the partition option of this module will be used.
This parameter is mutually exclusive with the disabled_vlans parameter.
fallback_persistence_profile
string
added in 2.3
Specifies the persistence profile you want the system to use if it cannot use the specified default persistence profile.
If you want to remove the existing fallback persistence profile, specify an empty value; "". See the documentation for an example.
When type is dhcp, this parameter will be ignored.
firewall_enforced_policy
string
added in 2.6
Applies the specify AFM policy to the virtual in an enforcing way.
When creating a new virtual, if this parameter is not specified, the enforced policy is disabled.
firewall_staged_policy
string
added in 2.6
Applies the specify AFM policy to the virtual in an enforcing way.
A staged policy shows the results of the policy rules in the log, while not actually applying the rules to traffic.
When creating a new virtual, if this parameter is not specified, the staged policy is disabled.
insert_metadata
boolean
added in 2.8
    Choices:
  • no
  • yes
When set to no it will not set metadata on the device.
Currently there is a limitation that non-admin users cannot set metadata on the object, despite being able to create and modify virtual server objects, setting this option to no will allow such users to utilize this module to manage Virtual Server objects on the device.
ip_intelligence_policy
string
added in 2.8
Specifies the IP intelligence policy applied to the virtual server.
This parameter requires that a valid BIG-IP security module such as ASM or AFM be provisioned.
ip_protocol
string
added in 2.6
    Choices:
  • ah
  • any
  • bna
  • esp
  • etherip
  • gre
  • icmp
  • ipencap
  • ipv6
  • ipv6-auth
  • ipv6-crypt
  • ipv6-icmp
  • isp-ip
  • mux
  • ospf
  • sctp
  • tcp
  • udp
  • udplite
Specifies a network protocol name you want the system to use to direct traffic on this virtual server.
When creating a new virtual server, if this parameter is not specified, the default is tcp.
The Protocol setting is not available when you select Performance (HTTP) as the Type.
The value of this argument can be specified in either it's numeric value, or, for convenience, in a select number of named values. Refer to choices for examples.
For a list of valid IP protocol numbers, refer to this page https://en.wikipedia.org/wiki/List_of_IP_protocol_numbers
When type is dhcp, this module will force the ip_protocol parameter to be 17 (UDP).
irules
list
added in 2.2
List of rules to be applied in priority order.
If you want to remove existing iRules, specify a single empty value; "". See the documentation for an example.
When type is dhcp, this parameter will be ignored.
When type is stateless, this parameter will be ignored.
When type is reject, this parameter will be ignored.
When type is internal, this parameter will be ignored.

aliases: all_rules
mask
string
added in 2.8
Specifies the destination address network mask. This parameter will work with IPv4 and IPv6 type of addresses.
This is an optional parameter which can be specified when creating or updating virtual server.
If destination is set in CIDR notation format and mask is provided the mask parameter takes precedence.
If catchall destination is specified, i.e. 0.0.0.0 for IPv4 :: for IPv6, mask parameter is set to any or any6 respectively.
When the destination is provided not in CIDR notation and mask is not specified, 255.255.255.255 or ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff is set for IPv4 and IPv6 addresses respectively.
When destination is provided in CIDR notation format and mask is not specified the mask parameter is inferred from destination.
When destination is provided as Virtual Address name, and mask is not specified, the mask will be None allowing device set it with its internal defaults.
metadata
raw
added in 2.5
Arbitrary key/value pairs that you can attach to a virtual server. This is useful in situations where you might want to annotate a virtual to be managed by Ansible.
Key names will be stored as strings; this includes names that are numbers.
Values for all of the keys will be stored as strings; this includes values that are numbers.
Data will be persisted, not ephemeral.
mirror
boolean
added in 2.8
    Choices:
  • no
  • yes
Specifies that the system mirrors connections on each member of a redundant pair.
When creating a new virtual server, if this parameter is not specified, the default is disabled.
name
string / required
Virtual server name.

aliases: vs
partition
string
added in 2.5
Default:
"Common"
Device partition to manage resources on.
password
string / required
The password for the user account used to connect to the BIG-IP.
You may omit this option by setting the environment variable F5_PASSWORD.

aliases: pass, pwd
policies
list
Specifies the policies for the virtual server.
When type is dhcp, this parameter will be ignored.
When type is reject, this parameter will be ignored.
When type is internal, this parameter will be ignored.

aliases: all_policies
pool
string
Default pool for the virtual server.
If you want to remove the existing pool, specify an empty value; "". See the documentation for an example.
When creating a new virtual server, and type is stateless, this parameter is required.
If type is stateless, the pool that is used must not have any members which define a rate_limit.
port
string
Port of the virtual server. Required when state is present and virtual server does not exist.
If you do not want to specify a particular port, use the value 0. The result is that the virtual server will listen on any port.
When type is dhcp, this module will force the port parameter to be 67.
When type is internal, this module will force the port parameter to be 0.
In addition to specifying a port number, a select number of service names may also be provided.
The string ftp may be substituted for for port 21.
The string http may be substituted for for port 80.
The string https may be substituted for for port 443.
The string telnet may be substituted for for port 23.
The string smtp may be substituted for for port 25.
The string snmp may be substituted for for port 161.
The string snmp-trap may be substituted for for port 162.
The string ssh may be substituted for for port 22.
The string tftp may be substituted for for port 69.
The string isakmp may be substituted for for port 500.
The string mqtt may be substituted for for port 1883.
The string mqtt-tls may be substituted for for port 8883.
port_translation
boolean
added in 2.6
    Choices:
  • no
  • yes
Specifies, when enabled, that the system translates the port of the virtual server.
When disabled, specifies that the system uses the port without translation. Turning off port translation for a virtual server is useful if you want to use the virtual server to load balance connections to any service.
When creating a new virtual server, the default is enabled.
profiles
list
List of profiles (HTTP, ClientSSL, ServerSSL, etc) to apply to both sides of the connection (client-side and server-side).
If you only want to apply a particular profile to the client-side of the connection, specify client-side for the profile's context.
If you only want to apply a particular profile to the server-side of the connection, specify server-side for the profile's context.
If context is not provided, it will default to all.
If you want to remove a profile from the list of profiles currently active on the virtual, then simply remove it from the profiles list. See examples for an illustration of this.
If you want to add a profile to the list of profiles currently active on the virtual, then simply add it to the profiles list. See examples for an illustration of this.
Profiles matter. This module will fail to configure a BIG-IP if you mix up your profiles, or, if you attempt to set an IP protocol which your current, or new, profiles do not support. Both this module, and BIG-IP, will tell you when you are wrong, with an error resembling lists profiles incompatible with its protocol.
If you are unsure what correct profile combinations are, then have a BIG-IP available to you in which you can make changes and copy what the correct combinations are.

aliases: all_profiles
context
string
    Choices:
  • all
  • server-side
  • client-side
The side of the connection on which the profile should be applied.
name
string
Name of the profile.
If this is not specified, then it is assumed that the profile item is only a name of a profile.
This must be specified if a context is specified.
provider
dictionary
added in 2.5
A dict object containing connection details.
password
string / required
The password for the user account used to connect to the BIG-IP.
You may omit this option by setting the environment variable F5_PASSWORD.

aliases: pass, pwd
server
string / required
The BIG-IP host.
You may omit this option by setting the environment variable F5_SERVER.
server_port
integer
Default:
443
The BIG-IP server port.
You may omit this option by setting the environment variable F5_SERVER_PORT.
ssh_keyfile
path
Specifies the SSH keyfile to use to authenticate the connection to the remote device. This argument is only used for cli transports.
You may omit this option by setting the environment variable ANSIBLE_NET_SSH_KEYFILE.
timeout
integer
Default:
10
Specifies the timeout in seconds for communicating with the network device for either connecting or sending commands. If the timeout is exceeded before the operation is completed, the module will error.
transport
string
    Choices:
  • cli
  • rest
Configures the transport connection to use when connecting to the remote device.
user
string / required
The username to connect to the BIG-IP with. This user must have administrative privileges on the device.
You may omit this option by setting the environment variable F5_USER.
validate_certs
boolean
    Choices:
  • no
  • yes
If no, SSL certificates are not validated. Use this only on personally controlled sites using self-signed certificates.
You may omit this option by setting the environment variable F5_VALIDATE_CERTS.
rate_limit
integer
added in 2.8
Virtual server rate limit (connections-per-second). Setting this to 0 disables the limit.
The valid value range is 0 - 4294967295.
rate_limit_dst_mask
integer
added in 2.8
Specifies a mask, in bits, to be applied to the destination address as part of the rate limiting.
The default value is 0, which is equivalent to using the entire address - 32 in IPv4, or 128 in IPv6.
The valid value range is 0 - 4294967295.
rate_limit_mode
string
added in 2.8
    Choices:
  • object
  • object-source
  • object-destination
  • object-source-destination
  • destination
  • source
  • source-destination
Indicates whether the rate limit is applied per virtual object, per source address, per destination address, or some combination thereof.
The default value is 'object', which does not use the source or destination address as part of the key.
rate_limit_src_mask
integer
added in 2.8
Specifies a mask, in bits, to be applied to the source address as part of the rate limiting.
The default value is 0, which is equivalent to using the entire address - 32 in IPv4, or 128 in IPv6.
The valid value range is 0 - 4294967295.
security_log_profiles
list
added in 2.6
Specifies the log profile applied to the virtual server.
To make use of this feature, the AFM module must be licensed and provisioned.
The Log all requests and Log illegal requests are mutually exclusive and therefore, this module will raise an error if the two are specified together.
security_nat_policy
dictionary
added in 2.7
Specify the Firewall NAT policies for the virtual server.
You can specify one or more NAT policies to use.
The most specific policy is used. For example, if you specify that the virtual server use the device policy and the route domain policy, the route domain policy overrides the device policy.
policy
string
Policy to apply a NAT policy directly to the virtual server.
The virtual server NAT policy is the most specific, and overrides a route domain and device policy, if specified.
To remove the policy, specify an empty string value.
use_device_policy
boolean
    Choices:
  • no
  • yes
Specify that the virtual server uses the device NAT policy, as specified in the Firewall Options.
The device policy is used if no route domain or virtual server NAT setting is specified.
use_route_domain_policy
boolean
    Choices:
  • no
  • yes
Specify that the virtual server uses the route domain policy, as specified in the Route Domain Security settings.
When specified, the route domain policy overrides the device policy, and is overridden by a virtual server policy.
server
string / required
The BIG-IP host.
You may omit this option by setting the environment variable F5_SERVER.
server_port
integer
added in 2.2
Default:
443
The BIG-IP server port.
You may omit this option by setting the environment variable F5_SERVER_PORT.
snat
string
Source network address policy.
When type is dhcp, this parameter is ignored.
When type is reject, this parameter will be ignored.
When type is internal, this parameter will be ignored.
The name of a SNAT pool (eg "/Common/snat_pool_name") can be specified to enable SNAT with the specific pool.
To remove SNAT, specify the word none.
To specify automap, use the word automap.
source
string
added in 2.5
Specifies an IP address or network from which the virtual server accepts traffic.
The virtual server accepts clients only from one of these IP addresses.
For this setting to function effectively, specify a value other than 0.0.0.0/0 or ::/0 (that is, any/0, any6/0).
In order to maximize utility of this setting, specify the most specific address prefixes covering all customer addresses and no others.
Specify the IP address in Classless Inter-Domain Routing (CIDR) format; address/prefix, where the prefix length is in bits. For example, for IPv4, 10.0.0.1/32 or 10.0.0.0/24, and for IPv6, ffe1::0020/64 or 2001:ed8:77b5:2:10:10:100:42/64.
source_port
string
added in 2.8
    Choices:
  • preserve
  • preserve-strict
  • change
Specifies whether the system preserves the source port of the connection.
When creating a new virtual server, if this parameter is not specified, the default is preserve.
state
string
    Choices:
  • present
  • absent
  • enabled
  • disabled
The virtual server state. If absent, delete the virtual server if it exists. present creates the virtual server and enable it. If enabled, enable the virtual server if it exists. If disabled, create the virtual server if needed, and set state to disabled.
type
string
added in 2.6
    Choices:
  • standard
  • forwarding-l2
  • forwarding-ip
  • performance-http
  • performance-l4
  • stateless
  • reject
  • dhcp
  • internal
  • message-routing
Specifies the network service provided by this virtual server.
When creating a new virtual server, if this parameter is not provided, the default will be standard.
This value cannot be changed after it is set.
When standard, specifies a virtual server that directs client traffic to a load balancing pool and is the most basic type of virtual server. When you first create the virtual server, you assign an existing default pool to it. From then on, the virtual server automatically directs traffic to that default pool.
When forwarding-l2, specifies a virtual server that shares the same IP address as a node in an associated VLAN.
When forwarding-ip, specifies a virtual server like other virtual servers, except that the virtual server has no pool members to load balance. The virtual server simply forwards the packet directly to the destination IP address specified in the client request.
When performance-http, specifies a virtual server with which you associate a Fast HTTP profile. Together, the virtual server and profile increase the speed at which the virtual server processes HTTP requests.
When performance-l4, specifies a virtual server with which you associate a Fast L4 profile. Together, the virtual server and profile increase the speed at which the virtual server processes layer 4 requests.
When stateless, specifies a virtual server that accepts traffic matching the virtual server address and load balances the packet to the pool members without attempting to match the packet to a pre-existing connection in the connection table. New connections are immediately removed from the connection table. This addresses the requirement for one-way UDP traffic that needs to be processed at very high throughput levels, for example, load balancing syslog traffic to a pool of syslog servers. Stateless virtual servers are not suitable for processing traffic that requires stateful tracking, such as TCP traffic. Stateless virtual servers do not support iRules, persistence, connection mirroring, rateshaping, or SNAT automap.
When reject, specifies that the BIG-IP system rejects any traffic destined for the virtual server IP address.
When dhcp, specifies a virtual server that relays Dynamic Host Control Protocol (DHCP) client requests for an IP address to one or more DHCP servers, and provides DHCP server responses with an available IP address for the client.
When internal, specifies a virtual server that supports modification of HTTP requests and responses. Internal virtual servers enable usage of ICAP (Internet Content Adaptation Protocol) servers to modify HTTP requests and responses by creating and applying an ICAP profile and adding Request Adapt or Response Adapt profiles to the virtual server.
When message-routing, specifies a virtual server that uses a SIP application protocol and functions in accordance with a SIP session profile and SIP router profile.
user
string / required
The username to connect to the BIG-IP with. This user must have administrative privileges on the device.
You may omit this option by setting the environment variable F5_USER.
validate_certs
boolean
added in 2.0
    Choices:
  • no
  • yes
If no, SSL certificates are not validated. Use this only on personally controlled sites using self-signed certificates.
You may omit this option by setting the environment variable F5_VALIDATE_CERTS.

Notes

Note

  • For more information on using Ansible to manage F5 Networks devices see https://www.ansible.com/integrations/networks/f5.
  • Requires BIG-IP software version >= 12.
  • The F5 modules only manipulate the running configuration of the F5 product. To ensure that BIG-IP specific configuration persists to disk, be sure to include at least one task that uses the bigip_config module to save the running configuration. Refer to the module’s documentation for the correct usage of the module to save your running configuration.

Examples

- name: Modify Port of the Virtual Server
  bigip_virtual_server:
    state: present
    partition: Common
    name: my-virtual-server
    port: 8080
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Delete virtual server
  bigip_virtual_server:
    state: absent
    partition: Common
    name: my-virtual-server
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Add virtual server
  bigip_virtual_server:
    state: present
    partition: Common
    name: my-virtual-server
    destination: 10.10.10.10
    port: 443
    pool: my-pool
    snat: Automap
    description: Test Virtual Server
    profiles:
      - http
      - fix
      - name: clientssl
        context: server-side
      - name: ilx
        context: client-side
    policies:
      - my-ltm-policy-for-asm
      - ltm-uri-policy
      - ltm-policy-2
      - ltm-policy-3
    enabled_vlans:
      - /Common/vlan2
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Add FastL4 virtual server
  bigip_virtual_server:
    destination: 1.1.1.1
    name: fastl4_vs
    port: 80
    profiles:
      - fastL4
    state: present
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Add iRules to the Virtual Server
  bigip_virtual_server:
    name: my-virtual-server
    irules:
      - irule1
      - irule2
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Remove one iRule from the Virtual Server
  bigip_virtual_server:
    name: my-virtual-server
    irules:
      - irule2
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Remove all iRules from the Virtual Server
  bigip_virtual_server:
    name: my-virtual-server
    irules: ""
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Remove pool from the Virtual Server
  bigip_virtual_server:
    name: my-virtual-server
    pool: ""
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Add metadata to virtual
  bigip_pool:
    state: absent
    name: my-pool
    partition: Common
    metadata:
      ansible: 2.4
      updated_at: 2017-12-20T17:50:46Z
    provider:
      server: lb.mydomain.com
      user: admin
      password: secret
  delegate_to: localhost

- name: Add virtual with two profiles
  bigip_pool:
    state: absent
    name: my-pool
    partition: Common
    profiles:
      - http
      - tcp
    provider:
      server: lb.mydomain.com
      user: admin
      password: secret
  delegate_to: localhost

- name: Remove HTTP profile from previous virtual
  bigip_pool:
    state: absent
    name: my-pool
    partition: Common
    profiles:
      - tcp
    provider:
      server: lb.mydomain.com
      user: admin
      password: secret
  delegate_to: localhost

- name: Add the HTTP profile back to the previous virtual
  bigip_pool:
    state: absent
    name: my-pool
    partition: Common
    profiles:
      - http
      - tcp
    provider:
      server: lb.mydomain.com
      user: admin
      password: secret
  delegate_to: localhost

- name: Add virtual server with rate limit
  bigip_virtual_server:
    state: present
    partition: Common
    name: my-virtual-server
    destination: 10.10.10.10
    port: 443
    pool: my-pool
    snat: Automap
    description: Test Virtual Server
    profiles:
      - http
      - fix
      - name: clientssl
        context: server-side
      - name: ilx
        context: client-side
    policies:
      - my-ltm-policy-for-asm
      - ltm-uri-policy
      - ltm-policy-2
      - ltm-policy-3
    enabled_vlans:
      - /Common/vlan2
    rate_limit: 400
    rate_limit_mode: destination
    rate_limit_dst_mask: 32
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

- name: Add FastL4 virtual server with clone_pools
  bigip_virtual_server:
    destination: 1.1.1.1
    name: fastl4_vs
    port: 80
    profiles:
      - fastL4
    state: present
    clone_pools:
      - pool_name: FooPool
        context: clientside
    provider:
      server: lb.mydomain.net
      user: admin
      password: secret
  delegate_to: localhost

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key Returned Description
address_translation
boolean
changed
The new value specifying whether address translation is on or off.

Sample:
True
clone_pools
list
changed
Pools to which virtual server copies traffic.

Sample:
[{'pool_name': '/Common/Pool1', 'context': 'clientside'}]
default_persistence_profile
string
changed
Default persistence profile set on the virtual server.

Sample:
/Common/dest_addr
description
string
changed
New description of the virtual server.

Sample:
This is my description
destination
string
changed
Destination of the virtual server.

Sample:
1.1.1.1
disabled
boolean
changed
Whether the virtual server is disabled, or not.

Sample:
True
disabled_vlans
list
changed
List of VLANs that the virtual is disabled for.

Sample:
['/Common/vlan1', '/Common/vlan2']
enabled
boolean
changed
Whether the virtual server is enabled, or not.

enabled_vlans
list
changed
List of VLANs that the virtual is enabled for.

Sample:
['/Common/vlan5', '/Common/vlan6']
fallback_persistence_profile
string
changed
Fallback persistence profile set on the virtual server.

Sample:
/Common/source_addr
firewall_enforced_policy
string
changed
The new enforcing firewall policy.

Sample:
/Common/my-enforced-fw
firewall_staged_policy
string
changed
The new staging firewall policy.

Sample:
/Common/my-staged-fw
ip_intelligence_policy
string
changed
The new IP Intelligence Policy assigned to the virtual.

Sample:
/Common/ip-intelligence
ip_protocol
integer
changed
The new value of the IP protocol.

Sample:
6
irules
list
changed
iRules set on the virtual server.

Sample:
['/Common/irule1', '/Common/irule2']
metadata
dictionary
changed
The new value of the virtual.

Sample:
{'key1': 'foo', 'key2': 'bar'}
mirror
boolean
changed
Specifies that the system mirrors connections on each member of a redundant pair.

Sample:
True
policies
list
changed
List of policies attached to the virtual.

Sample:
['/Common/policy1', '/Common/policy2']
pool
string
changed
Pool that the virtual server is attached to.

Sample:
/Common/my-pool
port
integer
changed
Port that the virtual server is configured to listen on.

Sample:
80
port_translation
boolean
changed
The new value specifying whether port translation is on or off.

Sample:
True
profiles
list
changed
List of profiles set on the virtual server.

Sample:
[{'name': 'tcp', 'context': 'server-side'}, {'name': 'tcp-legacy', 'context': 'client-side'}]
rate_limit
integer
changed
The maximum number of connections per second allowed for a virtual server.

Sample:
5000
rate_limit_dst_mask
integer
changed
Specifies a mask, in bits, to be applied to the destination address as part of the rate limiting.

Sample:
32
rate_limit_mode
string
changed
Sets the type of rate limiting to be used on the virtual server.

Sample:
object-source
rate_limit_src_mask
integer
changed
Specifies a mask, in bits, to be applied to the source address as part of the rate limiting.

Sample:
32
security_log_profiles
list
changed
The new list of security log profiles.

Sample:
['/Common/profile1', '/Common/profile2']
snat
string
changed
SNAT setting of the virtual server.

Sample:
Automap
source
string
changed
Source address, in CIDR form, set on the virtual server.

Sample:
1.2.3.4/32
source_port
string
changed
Specifies whether the system preserves the source port of the connection.

Sample:
change


Status

Authors

  • Tim Rupp (@caphrim007)
  • Wojciech Wypior (@wojtek0806)

Hint

If you notice any issues in this documentation you can edit this document to improve it.

© 2012–2018 Michael DeHaan
© 2018–2019 Red Hat, Inc.
Licensed under the GNU General Public License version 3.
https://docs.ansible.com/ansible/2.8/modules/bigip_virtual_server_module.html