filter data From ansible_default_ipv4.macaddress - linux

Question

Dear community i ask for your help please.
I would create a playbook that will take a macaddress given in input and it should respect the Unix format. Then, if the address given respects the required format, another task will check if the given macaddress match an existed one in the hosts, **if it exists it will show the interface related to that macaddress if not the task will fail with an error message "No interfaces found with mac address '$MACADDRESS'. Fatal error."
here is what was done by me, i don't what should be done to achieve the goal:
- hosts: all
gather_facts: no
vars_prompt:
- name: "MACADDRESS"
prompt: "mac address?(please use Unix format ex- 1a:2b:3c:4d:5e:6f )"
private: no
tasks:
- name: check macaddresssyntax
debug:
msg: "{{ MACADDRESS | ansible.utils.hwaddr('unix') }}"
register: mac_syntax
failed_when: mac_syntax failed
- name: check local mac
debug:
var: mac_syntax |intersect (ansible_facts['default_ipv4']|selectattr('macaddress') | map(attribute='interface')|list)

Answer 1

You don't normally register the result of a debug task (because it's not useful). If you want to fail when someone enters an invalid MAC address, use the fail task:
- name: check mac address syntax
fail:
msg: "Invalid mac address syntax"
when: not MACADDRESS|ansible.utils.hwaddr('unix')
You have gather_facts set to false, but with fact gathering
disabled Ansible won't provide you with any facts. You need to
enable fact gathering if you want Ansible to provide you with
information about host interfaces.
I'm not entirely sure what you're trying to do in your check local mac task, but this seems to accomplish what you were asking about:
- hosts: localhost
gather_facts: true
vars_prompt:
- name: "MACADDRESS"
prompt: "mac address?(please use Unix format ex- 1a:2b:3c:4d:5e:6f )"
private: no
tasks:
- name: check macaddresssyntax
fail:
msg: "Invalid mac address syntax"
when: not MACADDRESS | ansible.utils.hwaddr('unix')
# In this task, we loop over `ansible_interfaces`, which is
# a list of interface names. We set the `matched_interface`
# variable to the current interface name if it has a
# matching MAC address.
- name: check local mac
set_fact:
matched_interface: "{{ ifname }}"
when: >-
lookup('vars', 'ansible_{}'.format(ifname)).macaddress|default(false) == MACADDRESS
vars:
# For whatever reason, ansible replaces `-` in interface
# names with `_`.
ifname: "{{ item.replace('-', '_') }}"
loop: "{{ ansible_interfaces }}"
- debug:
msg: "the interface related to {{ MACADDRESS }} is {{ matched_interface }}"
when: matched_interface|default(false)
- fail:
msg: "no interfaces found with mac address {{ MACADDRESS }}"
when: not matched_interface|default(false)
Running the above playbook on my system, which has an interface with address a2:29:ab:4e:e7:74, looks like this:
$ ansible-playbook playbook.yaml -e MACADDRESS='a2:29:ab:4e:e7:74
PLAY [localhost] ***************************************************************
TASK [Gathering Facts] *********************************************************
ok: [localhost]
TASK [check macaddresssyntax] **************************************************
skipping: [localhost]
TASK [check local mac] *********************************************************
skipping: [localhost] => (item=veth92b9a89f)
...
ok: [localhost] => (item=example)
skipping: [localhost] => (item=lo)
...
TASK [debug] *******************************************************************
ok: [localhost] => {
"msg": "the interface related to a2:29:ab:4e:e7:74 is example"
}
TASK [fail] ********************************************************************
skipping: [localhost]
PLAY RECAP *********************************************************************
localhost : ok=3 changed=0 unreachable=0 failed=0 skipped=2 rescued=0 ignored=0
If I run it with a MAC address that doesn't exist on my system, I get:
TASK [check local mac] *********************************************************
skipping: [localhost] => (item=veth168ad56c)
...
TASK [debug] *******************************************************************
skipping: [localhost]
TASK [fail] ********************************************************************
fatal: [localhost]: FAILED! => {"changed": false, "msg": "no interfaces found with mac address a2:29:ab:4e:e7:77"}
PLAY RECAP *********************************************************************
localhost : ok=1 changed=0 unreachable=0 failed=1 skipped=3 rescued=0 ignored=0

Answer 2

Collect the network's facts and get the list of interfaces. For example,
- setup:
gather_subset: network
- debug:
var: ansible_facts.interfaces
gives
ansible_facts.interfaces:
- lo0
- lo1
- pflog0
- wlan0
Put the declaration below as appropriate
_ifcs: "{{ ansible_facts.interfaces|map('extract', ansible_facts)|list }}"
_macs: "{{ _ifcs|json_query('[].macaddress') }}"
_devs: "{{ _ifcs|json_query('[].device') }}"
_macs_valid: "{{ _macs|map('ansible.utils.hwaddr', 'bool')|
map('ternary', true, false)|list }}"
_dev_mac_valid: "{{ _devs|zip(_macs)|zip(_macs_valid)|
map('flatten')|
selectattr(2) }}"
dev_mac_valid: "{{ _dev_mac_valid|map('zip', ['dev', 'mac', 'valid'])|
map('map', 'reverse')|
map('community.general.dict') }}"
dev_mac: "{{ dev_mac_valid|items2dict(key_name='dev', value_name='mac') }}"
mac_dev: "{{ dev_mac_valid|items2dict(key_name='mac', value_name='dev') }}"
For example, these evaluate to
_macs: [unknown, unknown, unknown, '00:12:00:34:56:78']
_macs_valid: [false, false, false, true]
_devs: [lo0, lo1, pflog0, wlan0]
_dev_mac_valid:
- [wlan0, '00:12:00:34:56:78', true]
dev_mac_valid:
- dev: wlan0
mac: 00:12:00:34:56:78
valid: true
dev_mac:
wlan0: 00:12:00:34:56:78
mac_dev:
00:12:00:34:56:78: wlan0
Q: "Check if the given macaddress match an existing one in the hosts"
A: Use the dictionary mac_dev. For example,
- pause:
prompt: "Enter MAC address"
register: result
- set_fact:
macaddress: "{{ result.user_input }}"
- assert:
that: macaddress|ansible.utils.hwaddr('bool')
fail_msg: Wrong MAC address
- assert:
that: macaddress in mac_dev.keys()|list
fail_msg: "No interfaces found with mac address {{ macaddress }}"
success_msg: "Interfaces {{ mac_dev[macaddress] }} found
with mac address {{ macaddress }}"
If there are more hosts declare a dictionary of all hosts
mac_dev_hosts: "{{ dict(ansible_play_hosts|
zip(ansible_play_hosts|
map('extract', hostvars, 'mac_dev'))) }}"
Then, putting it all together, for example, the playbook
- hosts: test_11,test_12,test_13
gather_facts: false
vars:
_ifcs: "{{ ansible_facts.interfaces|map('extract', ansible_facts)|list }}"
_macs: "{{ _ifcs|json_query('[].macaddress') }}"
_devs: "{{ _ifcs|json_query('[].device') }}"
_macs_valid: "{{ _macs|map('ansible.utils.hwaddr', 'bool')|
map('ternary', true, false)|list }}"
_dev_mac_valid: "{{ _devs|zip(_macs)|zip(_macs_valid)|
map('flatten')|
selectattr(2) }}"
dev_mac_valid: "{{ _dev_mac_valid|map('zip', ['dev', 'mac', 'valid'])|
map('map', 'reverse')|
map('community.general.dict') }}"
dev_mac: "{{ dev_mac_valid|items2dict(key_name='dev', value_name='mac') }}"
mac_dev: "{{ dev_mac_valid|items2dict(key_name='mac', value_name='dev') }}"
mac_dev_hosts: "{{ dict(ansible_play_hosts|
zip(ansible_play_hosts|
map('extract', hostvars, 'mac_dev'))) }}"
tasks:
- setup:
gather_subset: network
- set_fact:
mac_dev: "{{ mac_dev }}"
- block:
- debug:
var: mac_dev_hosts|to_nice_yaml
- pause:
prompt: "Enter MAC address"
register: result
- set_fact:
macaddress: "{{ result.user_input }}"
- assert:
that: macaddress|ansible.utils.hwaddr('bool')
fail_msg: Wrong MAC address
- assert:
that: macaddress in mac_dev_hosts|json_query('*.keys(#)')|flatten
fail_msg: "No interface found with mac address {{ macaddress }}"
- debug:
msg: "Interface {{ dev }} found with mac address {{ macaddress }}
at {{ hst }}"
vars:
itm: "{{ mac_dev_hosts|dict2items|
selectattr('value', 'contains', macaddress)|first }}"
hst: "{{ itm.key }}"
dev: "{{ itm.value[macaddress] }}"
run_once: true
gives
PLAY [test_11,test_12,test_13] ***************************************************************
TASK [setup] *********************************************************************************
ok: [test_13]
ok: [test_12]
ok: [test_11]
TASK [set_fact] ******************************************************************************
ok: [test_13]
ok: [test_11]
ok: [test_12]
TASK [debug] *********************************************************************************
ok: [test_11] =>
mac_dev_hosts|to_nice_yaml: |-
test_11:
00:12:00:34:56:AA: wlan0
test_12:
00:12:00:34:56:BB: wlan0
test_13:
00:12:00:34:56:CC: wlan0
TASK [pause] *********************************************************************************
[pause]
Enter MAC address:
00:12:00:34:56:CC^Mok: [test_11]
TASK [set_fact] ******************************************************************************
ok: [test_11]
TASK [assert] ********************************************************************************
ok: [test_11] => changed=false
msg: All assertions passed
TASK [assert] ********************************************************************************
ok: [test_11] => changed=false
msg: All assertions passed
TASK [debug] *********************************************************************************
ok: [test_11] =>
msg: Interface wlan0 found with mac address 00:12:00:34:56:CC at test_13
PLAY RECAP ***********************************************************************************
test_11: ok=8 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
test_12: ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
test_13: ok=2 changed=0 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
If the MAC is missing the play will fail, for example
TASK [assert] ********************************************************************************
fatal: [test_11]: FAILED! => changed=false
assertion: macaddress in mac_dev_hosts|json_query('*.keys(#)')|flatten
evaluated_to: false
msg: No interface found with mac address 00:12:00:34:56:FF