Pre-requisites

Testbed

We're using the always-on DevNet sandboxes in the testbed.yaml file. More information about DevNet sandboxes here:

http://devnetsandbox.cisco.com/RM/Topology

We will be using XE and XR sandboxes for the exercises attached. Feel free to use others.

Dependencies

To install the pyats packages, please run the command below:

pip install "pyats[full]"

Supported Python versions

You can find the list of supported Python versions for pyATS here:

https://pubhub.devnetcloud.com/media/pyats-getting-started/docs/prereqs/prerequisites.html

Exercises

0. Get CLI show command output

In the first exercise, we will connect to the device and get an unstructured show command output (ex: show ip interface brief).

Output example

Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet1       10.10.20.48     YES other  up                    up    
GigabitEthernet2       unassigned      YES NVRAM  administratively down down  
GigabitEthernet3       unassigned      YES NVRAM  up                    up    
Loopback11             1.2.3.1         YES other  up                    up  

Complete instructions

Complete instructions can be found here

1. Get structured show command output

In the second exercise, we will leverage Genie parsers to get a structured output (JSON). Complete list of interfaces.

Output example

Loopback333 -- 3.3.3.3
Loopback99 -- 99.99.99.99
Loopback11 -- 1.2.3.1
GigabitEthernet2 -- Unassigned
GigabitEthernet1 -- 10.10.20.48
GigabitEthernet3 -- Unassigned

Complete instructions

Complete instructions can be found here

Genie parsers documentation

https://pubhub.devnetcloud.com/media/genie-feature-browser/docs/#/parsers

2. Get structured show command output for multiple OS (XE and XR)

In the third exercise, we will connect on multiple devices of the same testbed. They are running different OS (XE and XR). We will see that we can get the same structured output with the same line of code.

Output example

-----------------------------------
-- Connected on device: Cat8000V --
-----------------------------------
Loopback333 -- 3.3.3.3
Loopback99 -- 99.99.99.99
Loopback11 -- 1.2.3.1
GigabitEthernet2 -- Unassigned
GigabitEthernet1 -- 10.10.20.48
GigabitEthernet3 -- Unassigned

-----------------------------------
-- Connected on device: iosxr1 --
-----------------------------------
Loopback200 -- 1.1.1.200
Loopback100 -- 1.1.1.100
GigabitEthernet0/0/0/1 -- Unassigned
GigabitEthernet0/0/0/0 -- Unassigned
MgmtEth0/RP0/CPU0/0 -- 10.10.20.175
Null0 -- Unassigned

Complete instructions

Complete instructions can be found here

Genie supported models list

https://pubhub.devnetcloud.com/media/genie-feature-browser/docs/#/models

3. Diff between two config files

In this fourth exercise, we will connect on the CSR1000v sandbox. We will learn the configuration of the device, and save it in two files.

We will manually modify one of them, and use the Diff capability of Genie to print the change.

Output example

 interface Loopback2345:
- description Added via python Antoine script: 
+ description Added via python RESTCONF script: 
+ ip address 2.3.4.5 255.255.255.255: 
- ip address 2.3.4.6 255.255.255.255: 

Learning the configuration of a device

To learn the configuration of a device, the below command can be used:

device.learn('config')

Complete instructions

Complete instructions can be found here

Genie diff documentation

https://pubhub.devnetcloud.com/media/genie-docs/docs/userguide/utils/index.html#diff

4. AEtest: Automated Easy Testing

In this fifth exercise, we will use AEtest to define and execute test cases. In our example, we will:

1. Connect to the devices (IOS XE, IOS XR),
2. Assert their current OS version,
3. Disconnect from the devices.

Output example

2020-10-21T11:05:39: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:05:39: %AETEST-INFO: |                            Starting common setup                             |
2020-10-21T11:05:39: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:05:39: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:05:39: %AETEST-INFO: |                    Starting subsection connect_to_devices                    |
2020-10-21T11:05:39: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:05:40: %SCRIPT-INFO: Cat8000V connected
2020-10-21T11:05:42: %SCRIPT-INFO: iosxr1 connected
2020-10-21T11:05:42: %AETEST-INFO: The result of subsection connect_to_devices is => PASSED
2020-10-21T11:05:42: %AETEST-INFO: The result of common setup is => PASSED
2020-10-21T11:05:42: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:05:42: %AETEST-INFO: |                        Starting testcase CheckVersion                        |
2020-10-21T11:05:42: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:05:42: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:05:42: %AETEST-INFO: |                    Starting section check_current_version                    |
2020-10-21T11:05:42: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:01: %AETEST-INFO: The result of section check_current_version is => PASSED
2020-10-21T11:06:01: %AETEST-INFO: The result of testcase CheckVersion is => PASSED
2020-10-21T11:06:01: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:01: %AETEST-INFO: |                           Starting common cleanup                            |
2020-10-21T11:06:01: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:01: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:01: %AETEST-INFO: |                 Starting subsection disconnect_from_devices                  |
2020-10-21T11:06:01: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:27: %AETEST-INFO: The result of subsection disconnect_from_devices is => PASSED
2020-10-21T11:06:27: %AETEST-INFO: The result of common cleanup is => PASSED
2020-10-21T11:06:27: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:27: %AETEST-INFO: |                               Detailed Results                               |
2020-10-21T11:06:27: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:27: %AETEST-INFO:  SECTIONS/TESTCASES                                                      RESULT   
2020-10-21T11:06:27: %AETEST-INFO: --------------------------------------------------------------------------------
2020-10-21T11:06:27: %AETEST-INFO: .
2020-10-21T11:06:27: %AETEST-INFO: |-- common_setup                                                          PASSED
2020-10-21T11:06:27: %AETEST-INFO: |   `-- connect_to_devices                                                PASSED
2020-10-21T11:06:27: %AETEST-INFO: |-- CheckVersion                                                          PASSED
2020-10-21T11:06:27: %AETEST-INFO: |   `-- check_current_version                                             PASSED
2020-10-21T11:06:27: %AETEST-INFO: `-- common_cleanup                                                        PASSED
2020-10-21T11:06:27: %AETEST-INFO:     `-- disconnect_from_devices                                           PASSED
2020-10-21T11:06:27: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:27: %AETEST-INFO: |                                   Summary                                    |
2020-10-21T11:06:27: %AETEST-INFO: +------------------------------------------------------------------------------+
2020-10-21T11:06:27: %AETEST-INFO:  Number of ABORTED                                                            0 
2020-10-21T11:06:27: %AETEST-INFO:  Number of BLOCKED                                                            0 
2020-10-21T11:06:27: %AETEST-INFO:  Number of ERRORED                                                            0 
2020-10-21T11:06:27: %AETEST-INFO:  Number of FAILED                                                             0 
2020-10-21T11:06:27: %AETEST-INFO:  Number of PASSED                                                             3 
2020-10-21T11:06:27: %AETEST-INFO:  Number of PASSX                                                              0 
2020-10-21T11:06:27: %AETEST-INFO:  Number of SKIPPED                                                            0 
2020-10-21T11:06:27: %AETEST-INFO:  Total Number                                                                 3 
2020-10-21T11:06:27: %AETEST-INFO:  Success Rate                                                            100.0% 
2020-10-21T11:06:27: %AETEST-INFO: --------------------------------------------------------------------------------

Complete instructions

Complete instructions can be found here

AEtest documentation

https://pubhub.devnetcloud.com/media/pyats/docs/aetest/index.html

pyATS documentation

Official documentation

pyATS documentation can be found here:

https://pubhub.devnetcloud.com/media/pyats/docs/getting_started/index.html

List of supported platforms

The list of supported platforms can be found here:

https://pubhub.devnetcloud.com/media/unicon/docs/user_guide/supported_platforms.html

Typical errors

Below a list of errors I encountered and the resolution. The list is not aimed to be exhaustive.

Testbed file is not in the folder of execution

! output omitted
pyats.utils.yaml.exceptions.LoadError: Content of 'testbed.yaml' failed to load into a dict.

Hostname and testbed mismatch

The name of the device in your testbed, and the hostname MUST match. It's case-sensitive.

unicon.core.errors.TimeoutError: timeout occurred:

Otherwise, you can also set the learn_hostname argument to True.

device.connect(learn_hostname=True)

More information in the documentation below:

https://pubhub.devnetcloud.com/media/unicon/docs/user_guide/connection.html

Don't print the device output

Don't print the output.

device.connect(log_stdout=False)

device.learn('platform')

platform.os has the following values for IOSXE and IOSXR:

• iosxe >> lower case
• IOSXR >> upper case

disconnect() quickly

To avoid waiting ~10 seconds to disconnect on the device, you can edit your testbed.yaml file as such:

    connections:
      cli:
        protocol: telnet
        ip: 10.1.1.1
        settings:
          GRACEFUL_DISCONNECT_WAIT_SEC: 0
          POST_DISCONNECT_WAIT_SEC: 0

More info here:

https://pubhub.devnetcloud.com/media/unicon/docs/user_guide/connection.html

Parsing an already saved output

If you already have an output, and don't want to reconnect to the device to parse it, you can!

output = device.execute('<show command>')
device.parse('<show command>', output=output)