Collecting status from Arista EOS devices¶
Ansible provides 2 different modules to collect information from EOS devices:
eos_facts: Collect facts from devices such has Hardware, EOS version, configuration.eos_command: Collect result of any command you send to a device.
Collecting facts from devices.¶
This module collects all device facts from remote device. All keys found on device are prepend with ansible_net_. In addition of ](https://docs.ansible.com/ansible/latest/reference_appendices/common_return_values.html#common-return-values) collecting by Ansible, this module also collects following keys:
- All IPv4 addresses configured on the device
- All IPv6 addresses configured on the device
- The current active config from the device
- All file system names available on the device
- The fully qualified domain name of the device
- The list of fact subsets collected from the device
- The configured hostname of the device
- The image file the device is running
- A hash of all interfaces running on the system
- The available free memory on the remote device in Mb
- The total memory on the remote device in Mb
- The model name returned from the device
- The list of LLDP neighbors from the remote device
- The serial number of the remote device
- The operating system version running on the remote device
Collect all facts and display some variables¶
Below is a playbook example that grab all facts, register them into a variable named facts and then display output
---
- name: Run commands on remote LAB devices
hosts: lab
connection: network_cli
gather_facts: false
pre_tasks:
- include_vars: "authentication.yaml"
tasks:
- name: Collect all facts from device
eos_facts:
provider: "{{arista_credentials}}"
gather_subset:
- all
register: facts
- name: Display result
debug:
msg: "Model is {{facts.ansible_facts.ansible_net_model}} and it is running {{facts.ansible_facts.ansible_net_version}}"
Output of this playbook is quite easy to:
$ ansible-playbook pb.get.commands.yaml --limit ceos1
[...]
TASK [Display result] ********
ok: [ceos01] => {
"msg": "Model is cEOS and it is running 4.21.1.1F"
}
[...]
Save device configuration from facts¶
To save configuration, we can collect only configuration fact from device and save output to a file like in playbook below:
---
- name: Run commands on remote LAB devices
hosts: all
connection: local
gather_facts: false
pre_tasks:
- include_vars: "authentication.yaml"
tasks:
- name: Create output directory (if missing)
file:
path: "{{playbook_dir}}/config"
state: directory
- name: Collect all facts from device
eos_facts:
provider: "{{arista_credentials}}"
gather_subset:
- config
register: facts
- name: copy collected configuration in configuration/text directory
copy:
content: "{{ facts.ansible_facts.ansible_net_config }}"
dest: "{{ playbook_dir }}/config/{{ inventory_hostname }}.conf"
Playbook will create a folder named config if it is missing and then save config files:
$ ansible-playbook pb.get.commands.yaml
PLAY [Run commands on remote LAB devices] ********
TASK [include_vars] ********
ok: [ceos01]
ok: [ceos02]
TASK [Create output directory (if missing)] ********
ok: [ceos01]
ok: [ceos02]
TASK [Collect all facts from device] ********
ok: [ceos01]
ok: [ceos02]
TASK [copy collected configuration in configuration/text directory] ********
changed: [ceos01]
changed: [ceos02]
PLAY RECAP ********
ceos01 : ok=4 changed=1 unreachable=0 failed=0
ceos02 : ok=4 changed=1 unreachable=0 failed=0
And from your shell perspective:
$ tree -L 2
.
├── ansible.cfg
├── authentication.yaml
├── config
│ ├── ceos1.conf
│ └── ceos2.conf
├── group_vars
├── host_vars
│ ├── ceos1
│ └── ceos2
Collecting result of commands¶
Collect full command result:¶
Another module to collect status of EOS devices is eos_command module. It gives you a method to run commandon any Arista device and save result for further tasks.
Next playbook will monitor status of BGP peers:
---
- name: Run commands on remote LAB devices
hosts: all
connection: local
gather_facts: false
pre_tasks:
- include_vars: "authentication.yaml"
tasks:
- name: Collect BGP Status
eos_command:
commands:
- enable
- show ip bgp summary
provider: "{{arista_credentials}}"
register: bgp_status
- name: Display result
debug:
var: bgp_status
And the result is (truncated):
$ ansible-playbook pb.collect.status.bgp.yaml
PLAY [Run commands on remote LAB devices] ********
TASK [include_vars] ********
ok: [ceos1]
ok: [ceos2]
TASK [Collect BGP Status] ********
ok: [ceos2]
ok: [ceos1]
TASK [Display result] ********
ok: [ceos1] => {
"bgp_status": {
"changed": false,
"failed": false,
"stdout": [
{},
{
"vrfs": {
"default": {
"asn": 65001,
[...]
PLAY RECAP ********
ceos1 : ok=3 changed=0 unreachable=0 failed=0
ceos2 : ok=3 changed=0 unreachable=0 failed=0
Filter results using loop¶
Because Output is very verbose, we can reduce a bit to focus only on status of any configured peers by using with_dict loop management:
---
- name: Run commands on remote LAB devices
hosts: all
connection: local
gather_facts: false
pre_tasks:
- include_vars: "authentication.yaml"
tasks:
- name: Collect BGP Status
eos_command:
commands:
- enable
- show ip bgp summary
provider: "{{arista_credentials}}"
register: bgp_status
- name: Display result
debug:
msg: "Peering with {{item.key}} is {{item.value.peerState}}"
with_dict: "{{bgp_status.stdout[1].vrfs.default.peers}}"
And output is quite shorter than previous try:
$ ansible-playbook pb.collect.status.bgp.yaml
PLAY [Run commands on remote LAB devices] ********
TASK [include_vars] ********
ok: [ceos1]
ok: [ceos2]
TASK [Collect BGP Status] ********
ok: [ceos2]
ok: [ceos1]
TASK [Display result] ********
ok: [ceos1] => (item={'key': '10.0.0.2', 'value': {'msgSent': 33, 'inMsgQueue': 0, 'prefixReceived': 0, 'upDownTime': 1552640949.496501, 'version': 4, 'msgReceived': 32, 'prefixAccepted': 0, 'peerState': 'Established', 'outMsgQueue': 0, 'underMaintenance': False, 'asn': 65002}}) => {
"msg": "Peering with 10.0.0.2 is Established"
}
ok: [ceos2] => (item={'key': '10.0.0.1', 'value': {'msgSent': 32, 'inMsgQueue': 0, 'prefixReceived': 0, 'upDownTime': 1552640948.972306, 'version': 4, 'msgReceived': 32, 'prefixAccepted': 0, 'peerState': 'Established', 'outMsgQueue': 0, 'underMaintenance': False, 'asn': 65001}}) => {
"msg": "Peering with 10.0.0.1 is Established"
}
PLAY RECAP ********
ceos1 : ok=3 changed=0 unreachable=0 failed=0
ceos2 : ok=3 changed=0 unreachable=0 failed=0
Wait for a specific result¶
Waiting for a specific result is useful to set a task to fail or success depending on a change propagating in the network.
In this example, we are going to put one device in maintenance mode. To do that, we use a playbook to configure device in maintenance mode using eos_config and then waiting for result of this change with command show maintenance
---
- name: Run commands on remote LAB devices
hosts: ceos1
connection: local
gather_facts: false
pre_tasks:
- include_vars: "authentication.yaml"
tasks:
- name: Configure device hostname from lines
eos_config:
provider: "{{arista_credentials}}"
lines:
- quiesce
parents:
- maintenance
- unit System
- name: Wait for device to change to maintenance mode (10sec)
eos_command:
provider: "{{arista_credentials}}"
commands: show maintenance
wait_for: result[0]['units']['System']['state'] eq 'underMaintenance'
interval: 2
retries: 5
In case of these 10 seconds (5 tries with 2 seconds in between) are not enough, then, task fails:
$ ansible-playbook pb.collect.waitfor.maintenance.yaml
PLAY [Run commands on remote LAB devices] ********
TASK [include_vars] ********
ok: [ceos1]
TASK [Configure device hostname from lines] ********
ok: [ceos1]
TASK [Wait for device to change to maintenance mode (10sec)] ********
fatal: [ceos1]: FAILED! => {"changed": false, "failed_conditions": ["result[0]['units']['System']['state'] eq 'underMaintenance'"], "msg": "One or more conditional statements have not been satisf
ied"}
PLAY RECAP ********
ceos1 : ok=2 changed=0 unreachable=0 failed=1
But when device changes to underMaintenance, then, task is a success:
$ ansible-playbook pb.collect.waitfor.maintenance.yaml
PLAY [Run commands on remote LAB devices] ********
TASK [include_vars] ********
ok: [ceos1]
TASK [Configure device hostname from lines] ********
ok: [ceos1]
TASK [Wait for device to change to maintenance mode (10sec)] ********
ok: [ceos1]
PLAY RECAP ********
ceos1 : ok=3 changed=0 unreachable=0 failed=0