sFlow role
==========

This role facilitates the configuration of global and interface level sFlow attributes. It supports the configuration of sFlow collectors at the global level, enable/disable, and specification of sFlow polling-interval, sample-rate, max-datagram size, and so on are supported at the interface and global level. This role is abstracted for Dell EMC PowerSwitch platforms running Dell EMC OS9.

The sFlow role requires an SSH connection for connectivity to a Dell EMC OS9 device. You can use any of the built-in OS connection variables.


Role variables
--------------

- Role is abstracted using the `ansible_network_os` variable that can take the `dellemc.os9.os9` as the value
- If `os9_cfg_generate` is set to true, the variable generates the role configuration commands in a file
- Any role variable with a corresponding state variable set to absent negates the configuration of that variable
- Setting an empty value for any variable negates the corresponding configuration
- `os9_sflow` (dictionary) contains keys along with *interface name* (dictionary)
- Interface name can correspond to any of the valid os9 physical interfaces with the unique interface identifier name
- Interface name must be in *<interfacename> <tuple>* format; physical interface name can be in *fortyGigE 1/1* format
- Variables and values are case-sensitive

**os9_sflow keys**

| Key        | Type                      | Description                                             | Support               |
|------------|---------------------------|---------------------------------------------------------|-----------------------|
| ``sflow_enable`` | boolean: true,false\* | Enables sFlow at a global level  | os9 |
| ``collector``    | list                  | Configures collector information (see ``collector.*``); only two collectors can be configured on os9 devices | os9 |
| ``collector.collector_ip`` | string (required) | Configures an IPv4/IPv6 address for the collector | os9 |
| ``collector.agent_addr`` | string (required) | Configures an IPv4/IPv6 address for the sFlow agent to the collector | os9 |
| ``collector.udp_port`` | integer | Configures UDP port range at the collector level (1 to 65535) | os9 |
| ``collector.max_datagram_size`` | integer | Configures the maximum datagram size for the sFlow datagrams generated (400 to 1500) | os9 |
| ``collector.vrf`` | boolean: true,false* | Configures the management VRF to reach collector if set to true; can be enabled only for IPv4 collector addresses | os9 |
| ``polling_interval`` | integer | Configures the global default counter polling-interval (15 to 86400) | os9 |
| ``sample_rate`` | integer | Configures the global default sample-rate (256 to 8388608) | os9 |
| ``extended_switch`` | boolean: true,false\* | Enables packing extended information for the switch if set to true | os9  |
| ``max_header_size`` | boolean: true,false\* | Enables extended header copy size of 256 bytes if set to true at the global level | os9 |

> **NOTE**: Asterisk (\*) denotes the default value if none is specified.

**interface name keys**

| Key        | Type                      | Notes                                                   |
|------------|---------------------------|---------------------------------------------------------|
| ``sflow_enable`` | boolean: true,false\*   | Enables sFlow at the interface level  | 
| ``ingress_enable`` | boolean: true,false\* | Enables ingress sFlow at the interface level  | 
| ``polling_interval`` | integer | Configures the interface level default counter polling-interval (15 to 86400) |
| ``max_header_size`` | boolean: true,false\* | Enables extended header copy size of 256 bytes if set to true at the interface level |  
| ``sample_rate`` | integer | Configures the interface level default sample-rate (256 to 8388608) | 

> **NOTE**: Asterisk (\*) denotes the default value if none is specified. 

Connection variables
--------------------

Ansible Dell EMC network roles require connection information to establish communication with the nodes in your inventory. This information can exist in the Ansible *group_vars* or *host_vars* directories,or inventory or in the playbook itself.

| Key         | Required | Choices    | Description                                         |
|-------------|----------|------------|-----------------------------------------------------|
| ``ansible_host`` | yes      |            | Specifies the hostname or address for connecting to the remote device over the specified transport |
| ``ansible_port`` | no       |            | Specifies the port used to build the connection to the remote device; if value is unspecified, the `ANSIBLE_REMOTE_PORT` option is used; it defaults to 22 |
| ``ansible_ssh_user`` | no       |            | Specifies the username that authenticates the CLI login for the connection to the remote device; if value is unspecified, the `ANSIBLE_REMOTE_USER` environment variable value is used  |
| ``ansible_ssh_pass`` | no       |            | Specifies the password that authenticates the connection to the remote device  |
| ``ansible_become`` | no       | yes, no\*   | Instructs the module to enter privileged mode on the remote device before sending any commands; if value is unspecified, the `ANSIBLE_BECOME` environment variable value is used, and the device attempts to execute all commands in non-privileged mode |
| ``ansible_become_method`` | no       | enable, sudo\*   | Instructs the module to allow the become method to be specified for handling privilege escalation; if value is unspecified, the `ANSIBLE_BECOME_METHOD` environment variable value is used |
| ``ansible_become_pass`` | no       |            | Specifies the password to use if required to enter privileged mode on the remote device; if ``ansible_become`` is set to no this key is not applicable |
| ``ansible_network_os`` | yes      | os9, null\*  | Loads the correct terminal and cliconf plugins to communicate with the remote device |

> **NOTE**: Asterisk (\*) denotes the default value if none is specified.

Example playbook
----------------

This example uses the *os9_sflow* role to configure sFlow attributes at interface and global level. It creates a *hosts* file with the switch details and corresponding variables. The hosts file should define the `ansible_network_os` variable with the corresponding Dell EMC OS9 name. 

When `os9_cfg_generate` is set to true, the variable generates the configuration commands as a .part file in *build_dir* path. By default, the variable is set to false. It writes a simple playbook that only references the *os9_sflow* role. By including the role, you automatically get access to all of the tasks to configure sFlow features. 

**Sample hosts file**
 
    leaf1 ansible_host= <ip_address> 

**Sample host_vars/leaf1**

    hostname: leaf1
    ansible_become: yes
    ansible_become_method: xxxxx
    ansible_become_pass: xxxxx
    ansible_ssh_user: xxxxx
    ansible_ssh_pass: xxxxx
    ansible_network_os: dellemc.os9.os9
    build_dir: ../temp/os9
    os9_sflow:
      sflow_enable: true
      collector:
        - collector_ip: 1.1.1.1
          agent_addr: 2.2.2.2
          udp_port: 2
          max_datagram_size: 1000
          vrf: true
          state: present
      polling_interval: 30
      sample_rate: 1024
      extended_switch : true
      max_header_size: true
      fortyGigE 1/1:
        sflow_enable : true
        ingress_enable: true
        polling_interval: 30
        sample_rate: 1024
        max_header_size: true

**Simple playbook to setup sflow — leaf.yaml**

    - hosts: leaf1
      roles:
         - dellemc.os9.os9_sflow

**Run**

    ansible-playbook -i hosts leaf.yaml

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