Network Automation Example 1

Created for NetDevOps Live! Code Exchange Challenge

getdevpar script

The script

utilizes the Nornir (1.x) and NAPALM frameworks
prints all interfaces of device inventory group which contain specified string in the description
prints MAC address entries specified by the part of the MAC address for devices which are members of specified inventory group

Usage:

    Prints specified devices parameters
    Usage: getdevpar.py [OPTIONS]
    -d,     --debug                     debug (opt.)
    -h,     --help                      display help (opt.)
    -i,     --inventory                 inventory file
    -g,     --group                     inventory group
    -u,     --username                  username
    -p,     --password                  password (opt.)
    -c,     --command                   command (mac, desc)
    -m,     --mac                       part of mac address (used with command 'mac')
    -s,     --desc                      part of description (used with command 'desc')

Examples:

python3 getdevpar.py -i default_inventory.yaml -g access -c desc -s 'LX' -u cisco

python3 getdevpar.py -i default_inventory.yaml -g access -c mac -m '8014' -u cisco

Python environment

Create virtual environment and activate it (optional)

python3 -m venv venv
. venv/bin/activate

Install required modules

pip install -r requirements.txt

Create VIRL test environment (optional)

In .virl.rc file change the VIRL_HOST variable according to the IP/DNS name of your VIRL server

Create SSH keys on your workstation with empty password if you don't have it so far.

ssh-keygen -r rsa

Update ~/.ssh/config

host jumphost
  IdentityFile ~/.ssh/id_rsa
  # port 10000
  IdentitiesOnly yes
  user guest
  hostname 172.16.1.10
  StrictHostKeyChecking no
  UserKnownHostsFile=/dev/null

host 10.255.0.*
  StrictHostKeyChecking no
  UserKnownHostsFile=/dev/null
  ProxyCommand ssh jumphost nc %h %p

host 172.16.1.*         <- change this to the IP range of your Flat network
  StrictHostKeyChecking no
  UserKnownHostsFile=/dev/null

Spin up the simulation

virl up

VIRL simulation topology:

Enter 'virl nodes' command and note External Address of your ~mgmt-lxc

virl nodes
...
├───────────┼──────────┼─────────┼─────────────┼────────────┼──────────────────────┼────────────────────┤
│ ~mgmt-lxc │ mgmt-lxc │ ACTIVE  │ REACHABLE   │ ssh        │ 10.255.0.1           │ 172.16.1.10        │
├───────────┼──────────┼─────────┼─────────────┼────────────┼──────────────────────┼────────────────────┤

When the simulation is running (all nodes are in the ACTIVE state), create Ansible inventory file

virl generate ansible

Update the inventory file (default_inventory.yaml)

all:
  vars:
    ansible_network_os: ios
    nornir_nos: ios
    ansible_ssh_common_args: '-o ProxyCommand="ssh -W %h:%p guest@172.16.1.10"'  # set the IP address of your jump host (~lxc-flat, External Address)
    ansible_connection: network_cli
  children:

Copy ssh public key to the jumphost

ssh-copy-id guest@172.16.1.10       <-password guest

Update ~/.ansible.cfg

[defaults]
host_key_checking = False

Create VLANs etc using Ansible playbook (password is cisco)

ansible-playbook -i default_inventory.yaml vlans.yaml -u cisco -k

Connect to lxc and check if other lxcs are reachable

virl ssh lxc-11
cisco@10.255.0.11's password:   <- cisco

ping 10.0.0.11
ping 10.0.1.11

Now print all interfaces in the group access which have 'LX' in description

(venv) vagrant@ubuntu-xenial:~/NetAutoExample1$ python3 getdevpar.py -i default_inventory.yaml -g access -c desc -s 'LX' -u cisco
Password:
+---------+--------------------+-------------+
|   node  |     interface      | description |
+---------+--------------------+-------------+
| access2 | GigabitEthernet0/2 |    LXC 21   |
| access2 | GigabitEthernet0/3 |    LXC 22   |
| access1 | GigabitEthernet0/2 |    LXC 11   |
| access1 | GigabitEthernet0/3 |    LXC 12   |
+---------+--------------------+-------------+

Print all entries from MAC address table which contain '8014' as a part of the MAC address

venv) vagrant@ubuntu-xenial:~/NetAutoExample1$ python3 getdevpar.py -i default_inventory.yaml -g access -c mac -m '8014' -u cisco
Password:
+---------+-------------------+-----------+
|   node  |      mac_addr     | interface |
+---------+-------------------+-----------+
| access2 | 5E:00:00:02:80:14 |   Gi0/1   |
| access2 | 5E:00:00:03:80:14 |   Gi0/1   |
| access1 | 5E:00:00:02:80:14 |   Gi0/1   |
| access1 | 5E:00:00:03:80:14 |   Gi0/1   |
+---------+-------------------+-----------+

Connect to some node and check the way how RSA keys on routers in VIRL are created.
Thanks to sihart

Shutdown the simulation

virl down