api_haproxy

Introduction

This Django application covers build, generation, validation and deployment processes of a HAProxy configuration file lifecycle with common API calls. Project is developed as part of a Bachelor's thesis about NFV (Network Functions Virtualization). The application uses exceptions from the api_core submodule. An authentication introduced in api_core may be used as well, see section Deploying with authentication below for more details.

You may want to use a whole Django project implementing this application instead. You can find it at eszone_haproxy repository.

A typical use case may include this module in a Django project placed within a HAProxy virtual machine template labeling it a 'loadbalancer'. With the created template you can spawn virtual machines for your customers and then provide them with ways to configure it as they demand later on without need to access a virtual machine using ssh.

Installation

1. Submodule this application and api_core application into your Django project

   git submodule add *repository-link*

2. Append 'api_haproxy' and 'api_core' to INSTALLED_APPS in your Django project settings

3. Route submodules in a urls.py file in your Django project settings

    url(r'^my-url-auth/', include('api_core.urls')),
    url(r'^my-url/', include('api_haproxy.urls')),

Running API

For testing and development purposes, running API with a web server shipped in Django is fine enough. For production though, you may want to consider a production-ready web server like uwsgi or gunicorn. Deploying a Django application within one of these web servers is a matter of pointing to a wsgi.py file, which should be contained in your project's directory. In order how to configure these servers you can start reading Django documentation on how to deploy a Django project using uwsgi or gunicorn.

Interacting with API

API is intended to be used by a custom API client incorporated into your dashboard. For testing purposes, python httpie package can help a bit. Install it with a command:

pip install httpie

After installation, you can, for example, interact with an API using following commands:

http POST http://${IP}:${PORT}/v1/haproxy/section/ section='global' configuration='{"daemon": ""}'

http POST http://${IP}:${PORT}/v1/haproxy/configuration/generate/

http GET http://${IP}:${PORT}/v1/haproxy/configuration/validate/

Deploying with authentication

Currently, authentication from the api_core application is not integrated into api_haproxy. If you plan to use api_haproxy in a private network behind NAT and firewalls, there is probably no need to have an authentication enabled at all. On the other hand, if you plan to have some kind of authentication, here are steps to integrate the simple token authentication from api_core application:

• submodule api_core into your Django project

git submodule add *repository-link*

• import permissions and authentication modules by adding following lines to the top of a views.py file

    from rest_framework.permissions import IsAuthenticated
    from api_core.authentication import SimpleTokenAuthentication

• add permissions and authentication classes as attributes to each APIView you want to authenticate. For example:

    class TestAuthView(APIView):
        authentication_classes = (SimpleTokenAuthentication, )
        permission_classes = (IsAuthenticated, )

From now on, you can make HTTP requests with an authentication.token field in them, assuming you have created first token by hand.

• generation of a master token is accessible after running python manage.py migrate and submoduling an api_core app.

python manage.py shell

then, enter below listed commands in a sequence

    > from api_core.models import SimpleTokenAuthModel
    > token = SimpleTokenAuthModel()
    > token.save()
    > print token.token_uuid

Todo

• Refactor views.py and settings.py to implement an option 'enable authentication' from api_core submodule
• Make way to revert to a previous configuration file in HaProxyConfigDeployView, when subprocess.CalledProcessError exception is raised
• When raising DuplicateEntryException, pass in id of a original configuration block
• Always refactor to make code better