Arista Cloudvision® Portal RESTful API Client

Table of Contents

1. Overview
   • Requirements
2. Installation
   • Development: Run from Source
3. Getting Started
   • Connecting
   • CVP On Premises
   • CVaaS
   • CVP Version Handling
   • Examples
4. Notes For API Class Usage
   • Containers
5. Testing
6. Contact or Questions
7. Contributing
   • Working With Git
   • Submitting Pull Requests
   • Pull Request Semantics
8. License

Overview

This module provides a RESTful API client for Cloudvision® Portal (CVP) which can be used for building applications that work with Arista CVP.

When the class is instantiated the logging is configured. Either syslog, file logging, both, or none can be enabled. If neither syslog nor filename is specified then no logging will be performed.

This class supports creating a connection to a CVP node and then issuing subsequent GET and POST requests to CVP. A GET or POST request will be automatically retried on the same node if the request receives a requests.exceptions.Timeout or ReadTimeout error. A GET or POST request will be automatically retried on the same node if the request receives a CvpSessionLogOutError. For this case a login will be performed before the request is retried. For either case, the maximum number of times a request will be retried on the same node is specified by the class attribute NUM_RETRY_REQUESTS.

If more than one CVP node is specified when creating a connection, and a GET or POST request that receives a requests.exceptions.ConnectionError, requests.exceptions.HTTPError, or a requests.exceptions.TooManyRedirects will be retried on the next CVP node in the list. If a GET or POST request that receives a requests.exceptions.Timeout or CvpSessionLogOutError and the retries on the same node exceed NUM_RETRY_REQUESTS, then the request will be retried on the next node on the list.

If any of the errors persists across all nodes then the GET or POST request will fail and the last error that occurred will be raised.

The class provides connect, get, and post methods that allow the user to make RESTful API calls to CVP. See the example below using the get method.

The class provides a wrapper function around the CVP RESTful API operations. Each API method takes the RESTful API parameters as method parameters to the operation method. The API class was added to the client class because the API functions are required when using the CVP RESTful API and placing them in this library avoids duplicating the calls in every application that uses this class. See the examples below using the API methods.

Requirements

• Python 2.7 or later
• Python logging module
• Python requests module version 1.0.0 or later

Installation

The source code for cvprac is provided on Github at https://github.com/aristanetworks/cvprac. All current development is done in the develop branch. Stable released versions are tagged in the master branch and uploaded to https://pypi.python.org.

If your platform has internet access you can use the Python Package manager to install cvprac.

admin:~ admin$ sudo pip install cvprac

You can upgrade cvprac

admin:~ admin$ sudo pip install --upgrade cvprac

Development: Run from Source

We recommend running cvprac in a virtual environment. For more information, read this: http://docs.python-guide.org/en/latest/dev/virtualenvs/

These instructions will help you install and run cvprac from source. This is useful if you plan on contributing or if you would always like to see the latest code in the develop branch. Note that these steps require the pip and git commands.

Step 1: Clone the cvprac Github repo

# Go to a directory where you'd like to keep the source
admin:~ admin$ cd ~/projects
admin:~ admin$ git clone https://github.com/aristanetworks/cvprac
admin:~ admin$ cd cvprac

Step 2: Check out the desired version or branch

# Go to a directory where you'd like to keep the source
admin:~ admin$ cd ~/projects/cvprac

# To see a list of available versions or branches
admin:~ admin$ git tag
admin:~ admin$ git branch

# Checkout the desired version of code
admin:~ admin$ git checkout v1.0.3

Step 3: Install cvprac using Pip with -e switch

# Go to a directory where you'd like to keep the source
admin:~ admin$ cd ~/projects/cvprac

# Install
admin:~ admin$ sudo pip install -e ~/projects/cvprac

Step 4: Install cvprac development requirements

# Go to a directory where you'd like to keep the source
admin:~ admin$ pip install -r dev-requirements.txt

Getting Started

Once the package has been installed you can run the following example to verify that everything has been installed properly.

Connecting

Connecting to CVP will depend on your CVP setup. Several options are outlined below.

CVP On Premises

CVP On Premises is for users with CVP running on a local server or cluster of servers. This is the standard form of connection. Multiple examples below demonstrate connecting to CVP On Premises setups.

CVaaS

CVaaS is CloudVision as a Service. Users with CVaaS must use a REST API token for accessing CVP with REST APIs.

• In the case where users authenticate with CVP (CVaaS) using Oauth a
• REST API token is required to be generated and used for running REST
• APIs. In this case no username/password login is necessary, but the
• API token (via api_token parameter) must be provided to cvprac client
• with the is_cvaas parameter. In the case that the api_token is used
• for REST APIs the username and password will be ignored and the tenant
• parameter is not needed.

An example of a CVaaS connection is shown below.

Note that the token parameter was previously cvaas_token but this has been converted to api_token because tokens are also available for usage with On Prem CVP deployments. The api_token parameter name is more generic in this sense. If you are using the cvaas_token parameter please convert to api_token because the cvaas_token parameter will be deprecated in the future.

CVP Version Handling

The CVP RESTful APIs often change between releases of CVP. Cvprac attempts to mask these API changes from the user via making appropriate API calls based on the CVP version while attempting to maintain return data and not changing function names when possible. This helps maintain backward compatibility for users when they upgrade CVP so that any custom automation/scripts will continue to work. In some cases maintaining return data requires additional API calls so there are cases where this comes with the cost of a slight performance hit. Users are free to access the clients get(), post() and delete() methods and make API calls directly if they want to avoid the potential time delay of some API functions. The current API version information handled by cvprac is shown below.

• Current latest API version is 4.0 API version is set to latest
• available version for CVaaS API version is set to 4.0 for 2020.1.1 and
• beyond. API version is set to 3.0 for 2019.0.0 through 2020.1.0 API
• version is set to 2.0 for 2018.2.X API version is set to 1.0 for
• 2018.1.X and prior

Examples

Example using CVP On Prem client get method directly:

>>> from cvprac.cvp_client import CvpClient
>>> clnt = CvpClient()
>>> clnt.connect(['cvp1', 'cvp2', 'cvp3'], 'cvp_user', 'cvp_word')
>>> result = clnt.get('/cvpInfo/getCvpInfo.do')
>>> print result
{u'version': u'2016.1.0'}
>>>

Same example as above using the API method:

>>> from cvprac.cvp_client import CvpClient
>>> clnt = CvpClient()
>>> clnt.connect(['cvp1', 'cvp2', 'cvp3'], 'cvp_user', 'cvp_word')
>>> result = clnt.api.get_cvp_info()
>>> print result
{u'version': u'2016.1.0'}
>>>

Same example as above but connecting to CVaaS with a token: Note that the username and password parameters are required by the connect function but will be ignored when using api_token:

>>> from cvprac.cvp_client import CvpClient
>>> clnt = CvpClient()
>>> clnt.connect(nodes=['cvaas'], username='', password='', is_cvaas=True, api_token='user token')
>>> result = clnt.api.get_cvp_info()
>>> print result
{u'version': u'cvaas'}
>>>

Example using the API method to create a container, wait 5 seconds, then delete the container. Before running this example manually create a container named DC-1 on your CVP node.

>>> import time
>>> from cvprac.cvp_client import CvpClient
>>> clnt = CvpClient()
>>> clnt.connect(['cvp1'], 'cvp_user', 'cvp_word')
>>> parent = clnt.api.search_topology('DC-1')
>>> clnt.api.add_container('TORs', 'DC-1', parent['containerList'][0]['key'])
>>> child = clnt.api.search_topology('TORs')
>>> time.sleep(5)
>>> result = clnt.api.delete_container('TORs', child['containerList'][0]['key'], 'DC-1', parent['containerList'][0]['key'])
>>>

Notes for API Class Usage

Containers

With the API the containers are added for all cases. If you add the container to the original root container 'Tenant' then you have to do a refresh from the GUI to see the container after it is added or deleted. If the root container has been renamed or the parent container is not the root container then an add or delete will update the GUI without requiring a manual refresh.

Testing

The cvprac module provides system tests. To run the system tests, you will need to update the cvp_nodes.yaml file found in test/fixtures.

Requirements for running the system tests:

• Need one CVP node for test with a test user account. Create the same account on the switch used for testing. The user account information follows:

    username: CvpRacTest
    password: AristaInnovates
  
    If switch does not have correct username and/or password then the tests that
    execute tasks will fail with the following error:
  
    AssertionError: Execution for task id 220 failed and in the test log is the error:
  
    Failure response received from the netElement : ' Unauthorized User '
  

• Test has dedicated access to the CVP node.

• CVP node contains at least one device in a container.

• Container or device has at least one configlet applied.

To run the system tests:

• run make tests from the root of the cvprac source folder.

Contact or Questions

Cvprac is developed by Arista EOS+ CS and supported by the Arista EOS+ community. Support for the code is provided on a best effort basis by the Arista EOS+ CS team and the community. You can contact the team that develops these modules by sending an email to [email protected].

For customers that are looking for a premium level of support, please contact your local account team or email [email protected] for help.

Contributing

Contributing pull requests are gladly welcomed for this repository. Not only contributing to the code but also we encourage the users to contribute in the form of examples, docs, tutorials, and user guides.

Please note that all contributions that modify the library behavior require corresponding test cases otherwise the pull request will be rejected.

Working With Git

It is recommended to fork the project and then start development on the forked repository's develop branch. This can achieved with the below steps:

• Fork the repo then clone your fork, and configure the remotes:

    # Clone your fork of the repo into the current directory
    git clone https://github.com/<your-username>/cvprac
  
    # Navigate to the newly cloned directory
    cd cvprac
  
    # Assign the original repo to a remote called "upstream"
    git remote add upstream https://github.com/aristanetworks/cvprac.git
  

• If you cloned a while ago, get the latest changes from upstream:

    # Work on the develop branch of the forked repo
    git checkout develop
  
    # Pull the latest changes from the develop branch of aristanetworks cvprac
    git pull upstream develop
  

• Create a new topic branch (off the main project development branch) to contain your feature, change, or fix:

   git checkout -b <topic-branch-name>
  

• Commit your changes in logical chunks. Please adhere to these git commit message guidelines or your code is unlikely to be merged into the main project. Use Git's git rebase feature to tidy up your commits before making them public.

• Locally merge (or rebase) the upstream development branch into your topic branch every time before pushing it to your fork:

    # Here the <dev-branch> is develop
    git pull [--rebase] upstream <dev-branch>
  

• Push your topic branch up to your fork:

    git push origin <topic-branch-name>
  

• Open a Pull Request with a clear title, description and explain how to test the feature.

Submitting Pull Requests

• It is recommended to open an issue before starting work on a pull request to make sure if the same issue is not reported previously and someone is already working on that. When suggesting a new feature, also make sure it won't conflict with any work that's already in progress.

• Once the issue is opened either self-assign the issue or ask the maintainer to assign it for you. This will make sure no others are working on the same issue.

• All new functionality must include relevant tests where applicable.

• When submitting a pull request, please be sure to work off of the develop branch and not from other branches. The develop branch is used for ongoing development, while the master will hold the last stable version.

• To automate release-notes creation and make filtering process easier, it is strongly recommended to use conventional commit syntax at least for Pull Request (PR) title.

• All code submissions must follow the below criteria:

  • The issue/PR title should follow the semantic as described here
  • All the tests are updated and are passed successfully
  • Python syntax is valid

Pull Request Semantics

The Pull Request title should start with one of the below to easily segregate if its a feature add or a bug or something related documentation etc.

It is strongly recommended to use one from the below:

• Feat: Create a capability e.g. feature, test, dependency
• Fix: Fix an issue e.g. bug, typo, accident, misstatement
• Doc: Refactor of documentation, e.g. help files
• Example: Add a new example or modify an existing one
• Test: Add or refactor anything regarding test, e.g add a new testCases or missing testCases
• Refactor: A code change that MUST be just a refactoring
• Bump: Increase the version of something e.g. dependency
• Revert: Change back to the previous commit
• Optimize: Refactor of performance, e.g. speed up code
• CI: Update CI components, e.g. molecule files or Github Actions
• Cut: Remove a capability e.g. feature, test, dependency

For example:

• Feat: Add support for decommissioning APIs
• Test: Add missing test cases for change control
• Doc: Document new examples for change control

License

Copyright© 2020, Arista Networks, Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• Neither the name of Arista Networks nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ARISTA NETWORKS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.