djangomicroservices 0.1.2
Simple django package to easily connect microservices.
License: MIT

# django-microservices

## About
Simple django package to easily "connect" microservices.

The package loads the service configurations (id, name, host) into a DB table from a json file which can be stored on a shared drive, or hosted on URL.

## Installation
You can simply install the package with pip from **PyPI** or **GitHub**.

**Install with pip from github**

`pip install git+https://github.com/gabor-boros/django-microservices.git`

**Install from pypi**

`pip install djangomicroservices`

## Configuration
Add the `microservices` app to your `INSTALLED_APPS` like this:

```
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'microservices',
    ...
]
```

After you added it to the `INSTALLED_APPS`, you **must** configure the path where your service configuration exists.
The configuration file is a `json` file. Basically it is an output of `python manage.py dumpdata` command.
It doesn't matter where is your file located. It can be hosted on a website, or located on a *shared* drive.

```
SERVICE_CONFIGURATION_FILE = 'http://myserver.com/services.json'
```

or

```
SERVICE_CONFIGURATION_FILE = 'services.json'
```

**Service configuration example**
*sample.json*
```
[
    {
        "model": "microservices.service",
        "pk": 1,
        "fields": {
            "name": "auth",
            "host": "http://auth.example.com/",
        }
    },
    {
        "model": "microservices.service",
        "pk": 2,
        "fields": {
            "name": "search",
            "host": "http://search.example.com/",
        }
    }
]
```

## Usage
After you are done with the installation and configuration, and you loaded your services, you are good to go.
The usage is very simple. Query your service, and call the `remote_call` object method.

**Remote call example**
```
import json
from microservices.models import Service

def can_login(username, password):
    authentication_data = json.loads({"username": username: "password": password})

    authentication_service = Service.objects.get(name="auth")
    response = authentication_service.remote_call(
        method, api='/login/', data=authentication_data
    )

    if response.status_code == 200:
        return True

    return False

```

The package ships with an other object method called `update_availability`. This method can be used to update your service's status.
To do this you can call it for the object as shown in the example below.

**NOTE**
If the response code is 400, 404, 500 or 503, the value of `is_available` field will be `False`.

**Update service status**
```
from microservices.models import Service

for service in Service.objects.all():
    service.update_availability()

```

## Management commands
Three management command ships with this package to help to manage your service configuration.

* `list_services` - Lists your services ordered by their status
* `load_services` - Loads the configuration from the given resource location, set in `settings.py`
* `check_services` - Going thorough your configuration and tries to reach them.
    * If the host sends any response (which is not error related), the service will be marked available
    * If the response is an error, or the service can not be reached, the service's status will be unavailable

## Tests
To run the tests for this package use the `python manage.py test` command as usual
In case you would like to generate a **coverage** report as well, run the `run_test_coverage.sh` file.

## Contributors
If you would like to help to develop this package please read the CONTRIBUTING guideline. Every PR is highly welcomed.