SimpleScaleVM

This repository hosts a Python module to manage the autoscaling of a cluster of virtual instances called replicas. The full explanation of the functioning of this module is described in the documentation directory.

Configuration

All the configuration is contained in the .env environment file. To initialize it, launch the following command:

make .env

The precise description of all environment variables that are used to configure the Scaler is available in the Docker image README and on DockerHub, in the corresponding subsection.

Installation

Python virtualenv is used to run the module. To install it, launch the following command:

python3 -m pip install virtualenv

To setup the virtualenv and install the requirements, launch the following command:

make install

Launch the module

To start the module, launch the following command:

make start

Working with Docker

Once your project is configured, you can start working with Docker by building, launching and releasing on DockerHub with the respective commands:

make build
make start-docker
make release

Note that each provider has its specific Docker image version which contains the provider requirements: the Docker tag format is <provider>-<version>. In order to release a specific version of the module, you may modify the VERSION and PROVIDER environment variables.

The full documentation of the SimpleScaleVM Docker image is available on DockerHub.

Tests

In order to be able to test the scaling module, a simple HTTP webserver that listens on all GET requests and returns replica API responses can be launched with the following command:

make mock

Besides, this webserver may be configured in the tests/mock.env file with the following environment variables:

• MOCK_HOST: host of the HTTP server.
• MOCK_PORT: port of the HTTP server.
• MOCK_CAPACITY_KEY: key of the API response that corresponds to the number of available resources on the replica.
• MOCK_TERMINATION_KEY: key of the API response that corresponds to the boolean indicating if the replica should be terminated.
• MOCK_CAPACITY_VALUE: value linked to the MOCK_CAPACITY_KEY key.
• MOCK_TERMINATION_VALUE: value linked to the MOCK_TERMINATION_KEY key.

Licensing

Apache License Version 2.0.

See LICENSE to see the full text.