Extending OpenWISP Firmware Upgrader

Note

This page is for developers who want to customize or extend OpenWISP Firmware Upgrader, whether for bug fixes, new features, or contributions.

For user guides and general information, please see:

One of the core values of the OpenWISP project is Software Reusability, for this reason OpenWISP Firmware Upgrader provides a set of base classes which can be imported, extended and reused to create derivative apps.

In order to implement your custom version of OpenWISP Firmware Upgrader, you need to perform the steps described in this section.

When in doubt, the code in the test project and the sample app will serve you as source of truth: just replicate and adapt that code to get a basic derivative of OpenWISP Firmware Upgrader working.

Important

If you plan on using a customized version of this module, we suggest to start with it since the beginning, because migrating your data from the default module to your extended version may be time consuming.

1. Initialize your Custom Module 

The first thing you need to do is to create a new django app which will contain your custom version of OpenWISP Firmware Upgrader.

A django app is nothing more than a python package (a directory of python scripts), in the following examples we'll call this django app myupgrader, but you can name it how you want:

django-admin startapp myupgrader

Keep in mind that the command mentioned above must be called from a directory which is available in your PYTHON_PATH so that you can then import the result into your project.

Now you need to add myupgrader to INSTALLED_APPS in your settings.py, ensuring also that openwisp_firmware_upgrader has been removed:

INSTALLED_APPS = [
    # ... other apps ...
    # 'openwisp_firmware_upgrader'  <-- comment out or delete this line
    "myupgrader"
]

For more information about how to work with django projects and django apps, please refer to the django documentation.

2. Install `openwisp-firmware-upgrader`

Install (and add to the requirement of your project) openwisp-firmware-upgrader:

pip install openwisp-firmware-upgrader

3. Add `EXTENDED_APPS`

Add the following to your settings.py:

EXTENDED_APPS = ["openwisp_firmware_upgrader"]

4. Add `openwisp_utils.staticfiles.DependencyFinder`

Add openwisp_utils.staticfiles.DependencyFinder to STATICFILES_FINDERS in your settings.py:

STATICFILES_FINDERS = [
    "django.contrib.staticfiles.finders.FileSystemFinder",
    "django.contrib.staticfiles.finders.AppDirectoriesFinder",
    "openwisp_utils.staticfiles.DependencyFinder",
]

5. Add `openwisp_utils.loaders.DependencyLoader`

Add openwisp_utils.loaders.DependencyLoader to TEMPLATES in your settings.py:

TEMPLATES = [
    {
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        "OPTIONS": {
            "loaders": [
                "django.template.loaders.filesystem.Loader",
                "django.template.loaders.app_directories.Loader",
                "openwisp_utils.loaders.DependencyLoader",
            ],
            "context_processors": [
                "django.template.context_processors.debug",
                "django.template.context_processors.request",
                "django.contrib.auth.context_processors.auth",
                "django.contrib.messages.context_processors.messages",
            ],
        },
    }
]

6. Inherit the AppConfig Class 

Please refer to the following files in the sample app of the test project:

You have to replicate and adapt that code in your project.

For more information regarding the concept of AppConfig please refer to the "Applications" section in the django documentation.

7. Create your Custom Models 

For the purpose of showing an example, we added a simple "details" field to the models of the sample app in the test project.

You can add fields in a similar way in your models.py file.

Note

If you have questions about using, extending, or developing models, refer to the "Models" section of the Django documentation.

8. Add Swapper Configurations 

Once you have created the models, add the following to your settings.py:

# Setting models for swapper module
FIRMWARE_UPGRADER_CATEGORY_MODEL = "myupgrader.Category"
FIRMWARE_UPGRADER_BUILD_MODEL = "myupgrader.Build"
FIRMWARE_UPGRADER_FIRMWAREIMAGE_MODEL = "myupgrader.FirmwareImage"
FIRMWARE_UPGRADER_DEVICEFIRMWARE_MODEL = "myupgrader.DeviceFirmware"
FIRMWARE_UPGRADER_BATCHUPGRADEOPERATION_MODEL = (
    "myupgrader.BatchUpgradeOperation"
)
FIRMWARE_UPGRADER_UPGRADEOPERATION_MODEL = "myupgrader.UpgradeOperation"

Substitute myupgrader with the name you chose in step 1.

9. Create Database Migrations 

Create and apply database migrations:

./manage.py makemigrations
./manage.py migrate

For more information, refer to the "Migrations" section in the django documentation.

10. Create the Admin 

Refer to the admin.py file of the sample app.

To introduce changes to the admin, you can do it in two main ways which are described below.

For more information regarding how the django admin works, or how it can be customized, please refer to "The django admin site" section in the django documentation.

1. Monkey Patching 

If the changes you need to add are relatively small, you can resort to monkey patching.

For example:

from openwisp_firmware_upgrader.admin import (
    BatchUpgradeOperationAdmin,
    BuildAdmin,
    CategoryAdmin,
)

BuildAdmin.list_display.insert(1, "my_custom_field")
BuildAdmin.ordering = ["-my_custom_field"]

2. Inheriting Admin Classes 

If you need to introduce significant changes and/or you don't want to resort to monkey patching, you can proceed as follows:

from django.contrib import admin
from openwisp_firmware_upgrader.admin import (
    BatchUpgradeOperationAdmin as BaseBatchUpgradeOperationAdmin,
    BuildAdmin as BaseBuildAdmin,
    CategoryAdmin as BaseCategoryAdmin,
)
from openwisp_firmware_upgrader.swapper import load_model

BatchUpgradeOperation = load_model("BatchUpgradeOperation")
Build = load_model("Build")
Category = load_model("Category")
DeviceFirmware = load_model("DeviceFirmware")
FirmwareImage = load_model("FirmwareImage")
UpgradeOperation = load_model("UpgradeOperation")

admin.site.unregister(BatchUpgradeOperation)
admin.site.unregister(Build)
admin.site.unregister(Category)


class BatchUpgradeOperationAdmin(BaseBatchUpgradeOperationAdmin):
    # add your changes here
    pass


class BuildAdmin(BaseBuildAdmin):
    # add your changes here
    pass


class CategoryAdmin(BaseCategoryAdmin):
    # add your changes here
    pass

11. Create Root URL Configuration 

Please refer to the urls.py file in the test project.

For more information about URL configuration in django, please refer to the "URL dispatcher" section in the django documentation.

12. Create `celery.py`

Please refer to the celery.py file in the test project.

For more information about the usage of celery in django, please refer to the "First steps with Django" section in the celery documentation.

13. Import the Automated Tests 

When developing a custom application based on this module, it's a good idea to import and run the base tests too, so that you can be sure the changes you're introducing are not breaking some of the existing features of OpenWISP Firmware Upgrader.

In case you need to add breaking changes, you can overwrite the tests defined in the base classes to test your own behavior.

See the tests of the sample app to find out how to do this.

You can then run tests with:

# the --parallel flag is optional
./manage.py test --parallel myupgrader

Substitute myupgrader with the name you chose in step 1.

For more information about automated tests in django, please refer to "Testing in Django".

Other Base Classes That Can be Inherited and Extended 

The following steps are not required and are intended for more advanced customization.

`FirmwareImageDownloadView`

This view controls how the firmware images are stored and who has permission to download them.

The full python path is: openwisp_firmware_upgrader.private_storage.FirmwareImageDownloadView.

If you want to extend this view, you will have to perform the additional steps below.

Step 1. import and extend view:

# myupgrader/views.py
from openwisp_firmware_upgrader.private_storage import (
    FirmwareImageDownloadView as BaseFirmwareImageDownloadView,
)


class FirmwareImageDownloadView(BaseFirmwareImageDownloadView):
    # add your customizations here ...
    pass

Step 2: remove the following line from your root urls.py file:

path(
    "firmware/",
    include("openwisp_firmware_upgrader.private_storage.urls"),
),

Step 3: add an URL route pointing to your custom view in urls.py file:

# urls.py
from myupgrader.views import FirmwareImageDownloadView

urlpatterns = [
    # ... other URLs
    path(
        "<your-custom-path>",
        FirmwareImageDownloadView.as_view(),
        name="serve_private_file",
    ),
]

For more information regarding django views, please refer to the "Class based views" section in the django documentation.

API Views 

If you need to customize the behavior of the API views, the procedure to follow is similar to the one described in FirmwareImageDownloadView, with the difference that you may also want to create your own serializers if needed.

The API code is stored in openwisp_firmware_upgrader.api and is built using django-rest-framework

For more information regarding Django REST Framework API views, please refer to the "Generic views" section in the Django REST Framework documentation.

Extending OpenWISP Firmware Upgrader

Version