vpnmanager/manager/models.py

from django.db import models
from django.conf import settings
import uuid

def getRandom():
    return str(uuid.uuid4().hex)

class Organization(models.Model):
    name = models.CharField("Organization Name", max_length=300)
    users = models.ManyToManyField(settings.AUTH_USER_MODEL)

    def __str__(self):
        return self.name

class Network(models.Model):
    extip = models.CharField("External/Public IP", max_length=15)
    intip = models.CharField("Internal/Private IP", max_length=15)
    organizations = models.ManyToManyField(Organization)

    def __str__(self):
        return "%s (%s)" % (self.intip, self.extip)

class Device(models.Model):
    serial = models.CharField("Device Serial Number", max_length=12, unique=True)
    name = models.CharField("Common Name", max_length=100, blank=True, null=True)
    organization = models.ForeignKey(Organization, on_delete=models.CASCADE)
    network = models.ForeignKey(Network, on_delete=models.SET_NULL, blank=True, null=True)
    curip = models.CharField("Current IP Address", max_length=15, blank=True, null=True)
    lasttime = models.DateTimeField("Last Received Heartbeat", blank=True, null=True)
    secret = models.CharField("Secret", default=getRandom, max_length=128)
    reboot = models.BooleanField("Trigger Reboot", default=False)

    def __str__(self):
        return "%s%s" % (self.serial, " (%s)" % self.curip if self.curip else "")