Day: 16 July 2020

Today I was trying to write a playbook to push config to Arista devices.

Initially I wanted to use napalm module to push the config (as I have done with nornir) but it seems the napalm-ansible module requires napalm3 and netmiko3 and that breaks my nornir2.4 ( that requires napalm<3) So I uninstalled napalm-ansible and restored the other packages. Good thing i chekced the version before hand.

$ python -m pip list | grep -E 'nornir|napalm|netmiko|ansible'
ansible 2.9.10
napalm 2.5.0
netmiko 2.4.2
nornir 2.4.0

So I had to check the eos_config module. I think the napalm-ansible module is more powerful as it uses diff and sessions provided by Arista. As far as I can see, there is no option to say to the module to just make a dry run.

At the end I managed to put everything together but the eos_config was failing:

TASK [11- push config]
task path: xxx/testdir2/ceos-testing/ansible/playbooks/gen-config.yaml:60
fatal: [r1]: FAILED! => {
"changed": false,
"msg": "path specified in src not found"
}

The funny thing is all other tasks that needed to use templates were using the same path and were fine:

- name: 10- merge all configs in one file
  assemble:
    src: "CFGS/{{ inventory_hostname }}/" 
    dest: "CFGS/{{ inventory_hostname }}-full.txt"

- name: 11- push config
  debugger: on_failed
  eos_config:
    #src: "{{playbook_dir}}/../CFGS/{{ inventory_hostname }}-full.txt"
    src: "../CFGS/{{ inventory_hostname }}-full.txt"
    backup: yes

So I had to find out where that task was looking for the file. It seems “assemble“, “template” and “file” tasks use as pwd where I am calling the script (xxx/testdir2/ceos-testing/ansible). But “eos_config” is using where the playbook is (xxx/testdir2/ceos-testing/ansible/playbook) based on my running command “…/ansible master$ ansible-playbook playbooks/gen-config.yaml“.

So I was searching for some help and I found the playbook path and ansible search paths. So now I needed to verify that. I found some ansible debugger and examples that were really useful!

So I used “debugger: on_failed” for my task 11. And could see the path:

TASK [11- push config]
task path: /home/tomas/storage/technology/arista/testdir2/ceos-testing/ansible/playbooks/gen-config.yaml:60
fatal: [r1]: FAILED! => {
"changed": false,
"msg": "path specified in src not found"
}
[r1] TASK: 11- push config (debug)> p task.args
{'backup': True,
'src': '/home/tomas/storage/technology/arista/testdir2/ceos-testing/ansible/playbooks/CFGS/r1-full.txt'}
[r1] TASK: 11- push config (debug)> quit
User interrupted execution

So it is clear it was looking at the playbook dir.

So after fixing the path, I realised that I didn’t want to run everything and wanted to use tags so only the last part was executed.

/ansible master$ cat playbooks/gen-config.yaml
...
- name: 12- display result 
  debug: msg: "Backup file is {{ load_config.shortname }} and result is: {{ load_config }}" 
  tags: push_config
...

/ansible master$ ansible-playbook playbooks/gen-config.yaml --limit="r1" -vvv --tags "push_config"

One more thing, the output of ansible when you have dictionaries, it is not great. I checked this link and it is good for failures and with -vvvv. But for green outputs still not great:

TASK [12- - display result] *
task path: /home/tomas/storage/technology/arista/testdir2/ceos-testing/ansible/playbooks/gen-config.yaml:61
ok: [r1] =>
msg: 'Backup file is /home/tomas/storage/technology/arista/testdir2/ceos-testing/ansible/playbooks/backup/r1_config and result is: {''changed'': True, ''commands'': [''interface Ethernet1'', ''no shutdown'', ''interface Ethernet2'', ''no shutdown'', ''router bgp 100'', ''neighbor AS100-CORE password mpls-sr''], ''updates'': [''interface Ethernet1'', ''no shutdown'', ''interface Ethernet2'', ''no shutdown'', ''router bgp 100'', ''neighbor AS100-CORE password mpls-sr''], ''session'': ''ansible_1594920727'', ''backup_path'': ''/home/tomas/storage/technology/arista/testdir2/ceos-testing/ansible/playbooks/backup/r1_config.2020-07-16@18:32:07'', ''date'': ''2020-07-16'', ''time'': ''18:32:07'', ''shortname'': ''/home/tomas/storage/technology/arista/testdir2/ceos-testing/ansible/playbooks/backup/r1_config'', ''filename'': ''r1_config.2020-07-16@18:32:07'', ''failed'': False}'
META: ran handlers
META: ran handlers
PLAY RECAP
r1 : ok=3 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
(testdir2) go:1.12.5|py:3.7.3|tomas@athens:~/storage/technology/arista/testdir2/ceos-testing/ansible master$