Step 2: Verify pyATS Testbed File

Value Proposition: Ensure accurate network infrastructure mapping for seamless test automation and proactive issue mitigation.

For pyATS to work with network topology, it must know the following basic information: management interfaces, IP addresses, connection protocol, and connections between network devices.

This information is stored in the pyATS testbed file (YAML format).

The testbed YAML file for pyATS has been pre-created for this lab, and it is named pyats_testbed.yaml.

1. Change to the directory that contains the lab files:

   cd ~/LTRATO-2001
   

2. Open the pre-created pyats_testbed.yaml file in the Nano editor by entering the following command:

   nano pyats_testbed.yaml
   

3. The output of the command should contain the following:

   testbed:
   
     name: labpyats # name of topology simulation
   
     credentials: #  credentials for CLI access (stored as environment variables)
       default: #  username/password used by default
         username: "%ENV{PYATS_USERNAME}"
         password: "%ENV{PYATS_PASSWORD}"
       enable: #  enable password (if required)
         password: "%ENV{PYATS_AUTH_PASS}"
       line: #  line (VTY/console) password (if required)
         password: "%ENV{PYATS_AUTH_PASS}"
   
   devices: #  All necessary information to connect to devices is in this block
   asav-1:
       alias: asav-1
       os: asa
       type: ASAv
       platform: ASAv
   
       connections:
         console:
           protocol: ssh 
           ip: 198.18.1.202
           port: 22 #  connection to a device would be done via SSH port 
   
   # ...
   # Output ommitted
   # ...
   
   topology: #  All information about links between devices is in this block
     asav-1:
       interfaces:
         GigabitEthernet0/0:
           ipv4: 10.0.0.5/30
           link: asav-1-to-nx-osv-1
           type: ethernet
         GigabitEthernet0/1:
           ipv4: 10.0.0.9/30
           link: asav-1-to-nx-osv-1#1
           type: ethernet
   
         # ...
         # Output ommitted
         # ...
   

   Now we have all the required information to start our tests with pyATS.

   Note

   Note that username and passwords to access devices are not stored in the YAML file:

   credentials:
   default:
   username: "%ENV{PYATS_USERNAME}"
   password: "%ENV{PYATS_PASSWORD}"
   enable:
   password: "%ENV{PYATS_AUTH_PASS}"
   line:
   password: "%ENV{PYATS_AUTH_PASS}"
   

   We recommend you store credentials separately as environment variables.

4. Exit Nano without saving by pressing Ctrl + X

5. In the lab environment, variables for PYATS with credentials to access all devices are preconfigured. Check these environment variables from a Bash shell:

   echo $PYATS_USERNAME
   echo $PYATS_PASSWORD
   echo $PYATS_AUTH_PASS
   

6. The output of the command should contain the following:

   cisco
   cisco
   cisco
   

Section author: Luis Rueda <lurueda@cisco.com>, Jairo Leon <jaileon@cisco.com>