Django Portmaster

Django Portmaster is a network port allocation and management microservice. With Portmaster, you can assign port ranges to different services and register ports to different instances of those service. This way you can prevent assigning the same port twice, thus preventing assignement collision.

Installation

1. Install using PIP.

pip install django-portmaster

2. Add app to your Django project's settings file and include offer cleanup middleware.

INSTALLED_APPS = [
    [..]
    'django_portmaster'
]

MIDDLEWARE = [
    [..]
    'django_portmaster.middleware.CleanOldOffersMiddleware'
]

3. Include Portmaster's URLs into your Django project's urls file.

from django_portmaster.urls import portmaster_urlpatterns
urlpatterns += portmaster_urlpatterns

4. Optionally, you can override the time offers are kept before they are deleted. Add the following code to you settings.py file.

# Default value is 30 minutes
PM_DELETE_OFFERS_AFTER_MINUTES = 10

API

• Define port range by creating a service.

POST /v1/services

{
   "name": "django",
   "description": "Django service",
   "start": 5000,
   "end": 10000
}

• Request a port from the range by providing a service instance name.

POST /v1/services/django/offers

{
	"name": "web-01"
}

Response

{
    "service": "django",
    "name": "web-01",
    "port": 5000,
    "secret": "6f8ffc86-d98a-49ba-848a-a7cbaaea9360",
    "created": "2017-09-08T14:16:39.277408Z"
}

• Port will not be allocated immediately. Instead it will be reserved until the client accepts the port by posting to the dedicated URL using the provided secret code:

PUT /v1/services/django/offers/6f8ffc86-d98a-49ba-848a-a7cbaaea9360

Response

{
    "service": "django",
    "name": "web-01",
    "port": 5000,
    "created": "2017-09-08T14:18:04.094357Z"
}

• Alternatively, you can reject the offer. Offers that are not accepted are automatically deleted by Portmaster middleware after they reach threshold set by PM_DELETE_OFFERS_AFTER_MINUTES setting (default value is 30 minutes).

DELETE /v1/services/django/offers/6f8ffc86-d98a-49ba-848a-a7cbaaea9360

• You can list all port allocations for a particular service.

GET /v1/services/django/ports

• Find one by port number

GET /v1/services/django/ports/5000

• Or find one by service instance name

GET /v1/services/django/ports/web-01

Safe guards

Portmaster includes multiple error checks and corner case handlers, so:

• Service name needs to be unique
• Port ranges can not overlap
• Port range can not overlap with privileged ports (<1024) or IANA defined ephemeral port range (>49152)
• Port can be assigned only once at any given time
• Service instance name needs to be unique