PPP libmodule-Python application.

How to install

With a recent version of pip:

pip3 install git+https://github.com/ProjetPP/PPP-libmodule-Python.git

With an older one:

git clone https://github.com/ProjetPP/PPP-libmodule-Python.git
cd PPP-libmodule-Python
python3 setup.py install

Use the --user option if you want to install it only for the current user.

How to use the HTTP library

The module creation script should have created a requesthandler.py file with two methods to implement:

__init__(self, request), where request is the content of the request object sent by a client (deserialized from JSON)
answer(self), which returns a list of response objects to the client

See the specification to learn more about what those objects are.

answer may also raise one of those exceptions:

ppp_libmodule.exceptions.ClientError, which will tell the client their request has a problem. The first argument to the exception must contain an explicit message
ppp_libmodule.exception.InvalidConfig, raised when the administrator of your router did not configure it well. Displays the error message in the console and exits

Any other exception is caught and logged, and an “Internal Server Error” is served to the client.

How to use the configuration library

ppp_libmodule provides a simple wrapper around JSON configuration files you can use easily.

from ppp_libmodule.config import Config as BaseConfig
from ppp_libmodule.exception import InvalidConfig

class Config(BaseConfig):
    config_path_variable = 'PPP_MYMODULE_CONFIG'

    def parse_config(self, data):
        # parse your config here

There are two things to implement:

The name of the configuration variable. This is the name of the environment variable that will be read to know where to find the configuration file of your module. For instance: PPP_CORE_CONFIG or PPP_NLP_CLASSICAL_CONFIG.
The configuration parser: it simply takes the deserialized data from the file, and sets attributes to the Config object, so your module can access it later.

This way, the path to the config file can be passed to your module by invoking gunicorn this way:

export PPP_MYMODULE_CONFIG="/path/to/config/file.json"
gunicorn my_module:app