Write pxeconfig files per host

- Autogenerate pxe_key if missing
- Adds AppConfig
- Move signals to own file
- Fixes local_setting simport on python 3

mdb/__init__.py

@@ -0,0 +1 @@
+default_app_config = 'mdb.apps.MdbAppConfig'

mdb/apps.py

@@ -0,0 +1,10 @@
+from django.apps import AppConfig
+
+
+class MdbAppConfig(AppConfig):
+    name = 'mdb'
+    verbose_name = 'Machine Database'
+
+    def ready(self):
+        # all models are loaded, now attach signals
+        import mdb.signals

mdb/models.py

@@ -1,17 +1,14 @@
 from django.db import models
 from django.db.models import Count
-from django.db.models.signals import post_save, pre_save, pre_delete
-from django.dispatch import receiver
 from django.utils.encoding import python_2_unicode_compatible
 from django.utils.six import u
 from django.utils.translation import ugettext_lazy as _
-
+from mdb.utils import host_as_pxe_files
 
 from mdb.validators import validate_hostname, validate_macaddr
 
 import ipaddress
 import datetime
-import re
 
 
 @python_2_unicode_compatible
@@ -548,6 +545,9 @@ class Host(models.Model):
         addresses = self.interface_set.filter(ip4address__isnull=False).values_list('ip4address__address', flat=True)
         return ",".join(addresses)
 
+    def as_pxe_files(self):
+        return host_as_pxe_files(self)
+
 
 @python_2_unicode_compatible
 class Interface(models.Model):
@@ -585,125 +585,3 @@ class Ip6Address(models.Model):
     class Meta:
         verbose_name = 'IPv6 address'
         verbose_name_plural = 'IPv6 addresses'
-
-
-def format_domain_serial_and_add_one(serial):
-    today = datetime.datetime.now()
-    res = re.findall("^%4d%02d%02d(\d\d)$" % (
-        today.year, today.month, today.day), str(serial), re.DOTALL)
-
-    if len(res) == 0:
-        """ This probably means that the serial is malformed
-        or the date is wrong. We assume that if the date is wrong,
-        it is in the past. Just create a new serial starting from 1."""
-        return "%4d%02d%02d%02d" % \
-            (today.year, today.month, today.day, 1)
-    elif len(res) == 1:
-        """ The serial contains todays date, just update it. """
-        try:
-            number = int(res[0])
-        except:
-            number = 1
-        if number >= 99:
-            """ This is bad... Just keep the number on 99.
-            We also send a mail to sysadmins telling them that
-            something is wrong..."""
-
-        else:
-            number += 1
-        return "%4d%02d%02d%02d" % (
-            today.year, today.month, today.day, number)
-    else:
-        """ Just return the first serial for today. """
-        return "%4d%02d%02d%02d" % \
-            (today.year, today.month, today.day, 1)
-
-
-@receiver(post_save, sender=Ip4Subnet)
-def create_ips_for_subnet(sender, instance, created, **kwargs):
-    if not created:
-        return
-
-    subnet = ipaddress.IPv4Network(instance.network + "/" + instance.netmask)
-
-    for addr in subnet.hosts():
-        address = Ip4Address(address=str(addr), subnet=instance)
-        address.save()
-
-
-@receiver(pre_delete, sender=Ip4Subnet)
-def delete_ips_for_subnet(sender, instance, **kwargs):
-    for addr in instance.ip4address_set.all():
-        addr.delete()
-
-
-@receiver(pre_save, sender=Ip4Subnet)
-def set_domain_name_for_subnet(sender, instance, **kwargs):
-    # we assume that the reverse domain_name does not change
-    if len(instance.domain_name) == 0:
-        ipspl = instance.network.split(".")
-        rev = "%s.%s.%s" % (ipspl[2], ipspl[1], ipspl[0])
-        instance.domain_name = "%s.in-addr.arpa" % rev
-
-    # update it's own serial
-    # if instance.domain_serial is not None:
-    #     instance.domain_serial = format_domain_serial_and_add_one(instance.domain_serial)
-
-    # lets update the serial of the dhcp config
-    # when the subnet is changed
-    if instance.dhcp_config:
-        # instance.dhcp_config.serial = instance.dhcp_config.serial + 1
-        instance.dhcp_config.serial = format_domain_serial_and_add_one(instance.dhcp_config.serial)
-        instance.dhcp_config.save()
-
-
-@receiver(pre_save, sender=Ip6Subnet)
-def set_domain_name_for_ipv6_subnet(sender, instance, **kwargs):
-    if len(instance.domain_name) > 0:
-        return
-
-    network = ipaddress.IPv6Address("%s::" % instance.network)
-    instance.domain_name = ".".join(network.exploded.replace(":", "")[:16])[::-1] + ".ip6.arpa"
-
-
-@receiver(post_save, sender=Interface)
-def update_domain_serial_when_change_to_interface(sender, instance, created, **kwargs):
-    if instance.domain is not None:
-        domain = instance.domain
-        domain.domain_serial = format_domain_serial_and_add_one(domain.domain_serial)
-        domain.save()
-
-    if instance.ip4address is not None:
-        subnet = instance.ip4address.subnet
-        subnet.domain_serial = format_domain_serial_and_add_one(subnet.domain_serial)
-        subnet.save()
-
-
-@receiver(post_save, sender=Host)
-def update_domain_serial_when_change_to_host(sender, instance, created, **kwargs):
-    for interface in instance.interface_set.all():
-        if interface.domain is not None:
-            domain = interface.domain
-            domain.domain_serial = format_domain_serial_and_add_one(domain.domain_serial)
-            domain.save()
-        if interface.ip4address is not None:
-            subnet = interface.ip4address.subnet
-            subnet.domain_serial = format_domain_serial_and_add_one(subnet.domain_serial)
-            subnet.save()
-
-
-@receiver(pre_delete, sender=Interface)
-def update_domain_serial_when_interface_deleted(sender, instance, **kwargs):
-    if instance.domain is not None:
-        domain = instance.domain
-        domain.domain_serial += 1
-        domain.save()
-
-    if instance.ip4address is not None:
-        subnet = instance.ip4address.subnet
-        subnet.domain_serial += 1
-        subnet.save()
-
-# @receiver(pre_save, sender=Domain)
-# def update_domain_serial_when_domain_is_saved(sender, instance, **kwargs):
-#    instance.domain_serial = format_domain_serial_and_add_one(instance.domain_serial)

mdb/signals.py

@@ -0,0 +1,121 @@
+import logging
+import os
+import uuid
+from django.conf import settings
+from django.db.models.signals import pre_delete, post_save, pre_save
+from django.dispatch import receiver
+import ipaddress
+
+from mdb.models import Interface, Host, Ip6Subnet, Ip4Subnet, Ip4Address
+from mdb.utils import format_domain_serial_and_add_one
+
+logger = logging.getLogger(__name__)
+
+
+@receiver(post_save, sender=Ip4Subnet)
+def create_ips_for_subnet(sender, instance, created, **kwargs):
+    if not created:
+        return
+
+    subnet = ipaddress.IPv4Network(instance.network + "/" + instance.netmask)
+
+    for addr in subnet.hosts():
+        address = Ip4Address(address=str(addr), subnet=instance)
+        address.save()
+
+
+@receiver(pre_delete, sender=Ip4Subnet)
+def delete_ips_for_subnet(sender, instance, **kwargs):
+    for addr in instance.ip4address_set.all():
+        addr.delete()
+
+
+@receiver(pre_save, sender=Ip4Subnet)
+def set_domain_name_for_subnet(sender, instance, **kwargs):
+    # we assume that the reverse domain_name does not change
+    if len(instance.domain_name) == 0:
+        ipspl = instance.network.split(".")
+        rev = "%s.%s.%s" % (ipspl[2], ipspl[1], ipspl[0])
+        instance.domain_name = "%s.in-addr.arpa" % rev
+
+    # update it's own serial
+    # if instance.domain_serial is not None:
+    #     instance.domain_serial = format_domain_serial_and_add_one(instance.domain_serial)
+
+    # lets update the serial of the dhcp config
+    # when the subnet is changed
+    if instance.dhcp_config:
+        # instance.dhcp_config.serial = instance.dhcp_config.serial + 1
+        instance.dhcp_config.serial = format_domain_serial_and_add_one(instance.dhcp_config.serial)
+        instance.dhcp_config.save()
+
+
+@receiver(pre_save, sender=Ip6Subnet)
+def set_domain_name_for_ipv6_subnet(sender, instance, **kwargs):
+    if len(instance.domain_name) > 0:
+        return
+
+    network = ipaddress.IPv6Address("%s::" % instance.network)
+    instance.domain_name = ".".join(network.exploded.replace(":", "")[:16])[::-1] + ".ip6.arpa"
+
+
+@receiver(post_save, sender=Interface)
+def update_domain_serial_when_change_to_interface(sender, instance, created, **kwargs):
+    if instance.domain is not None:
+        domain = instance.domain
+        domain.domain_serial = format_domain_serial_and_add_one(domain.domain_serial)
+        domain.save()
+
+    if instance.ip4address is not None:
+        subnet = instance.ip4address.subnet
+        subnet.domain_serial = format_domain_serial_and_add_one(subnet.domain_serial)
+        subnet.save()
+
+
+@receiver(post_save, sender=Host)
+def update_domain_serial_when_change_to_host(sender, instance, created, **kwargs):
+    for interface in instance.interface_set.all():
+        if interface.domain is not None:
+            domain = interface.domain
+            domain.domain_serial = format_domain_serial_and_add_one(domain.domain_serial)
+            domain.save()
+        if interface.ip4address is not None:
+            subnet = interface.ip4address.subnet
+            subnet.domain_serial = format_domain_serial_and_add_one(subnet.domain_serial)
+            subnet.save()
+
+
+@receiver(post_save, sender=Host)
+def create_pxe_key_and_write_pxe_files_when_host_changes(sender, instance, created, **kwargs):
+    if not instance.pxe_key:
+        # generate key (prevent infinite recursion by using update)
+        pxe_key = uuid.uuid4().hex
+        Host.objects.filter(pk=instance.pk).update(pxe_key=pxe_key)
+        instance.pxe_key = pxe_key
+
+    for pxe_file_name, pxe_file in instance.as_pxe_files():
+        path = os.path.join(settings.MDB_PXE_TFTP_ROOT, pxe_file_name)
+        if instance.pxe_installable:
+            with open(path, 'w+') as f:
+                f.write(pxe_file)
+                logger.info("Created or updated {}".format(path))
+        else:
+            os.unlink(path)
+            logger.info("deleted {}".format(path))
+
+
+@receiver(pre_delete, sender=Interface)
+def update_domain_serial_when_interface_deleted(sender, instance, **kwargs):
+    if instance.domain is not None:
+        domain = instance.domain
+        domain.domain_serial += 1
+        domain.save()
+
+    if instance.ip4address is not None:
+        subnet = instance.ip4address.subnet
+        subnet.domain_serial += 1
+        subnet.save()
+
+# @receiver(pre_save, sender=Domain)
+# def update_domain_serial_when_domain_is_saved(sender, instance, **kwargs):
+#    instance.domain_serial = format_domain_serial_and_add_one(instance.domain_serial)

mdb/templates/pxelinux.cfg

@@ -0,0 +1,4 @@
+kernel {{kernel}}
+append ramdisk_size=14984 locale=en_US console-setup/ask_detect=false keyboard-configuration/layoutcode=no netcfg/wireless_wep= netcfg_choose_interface=eth0 netcfg/get_hostname= preseed/url={{preseed_config_url}} vga=normal initrd={{initrd}} -- snop={{host.pxe_key}}
+prompt 0
+timeout 0

mdb/tests.py

@@ -1,9 +1,11 @@
 from django.contrib.auth.models import User
 from django.core.urlresolvers import reverse
-from mdb.models import Host
+from django.test import TestCase
 from rest_framework.authtoken.models import Token
 from rest_framework.test import APITestCase
 
+from mdb.models import Host
+
 
 class MyAPITestCases(APITestCase):
     fixtures = ['test_data']
@@ -26,3 +28,11 @@ class MyAPITestCases(APITestCase):
         res = self.client.post(reverse('api-validate-host-secret'), data, format='json')
         self.assertEquals(res.status_code, 200, res.content)
         self.assertFalse(Host.objects.get(pk=self.host.pk).pxe_installable)
+
+
+class UnitTests(TestCase):
+    fixtures = ['test_data']
+
+    def test_host_as_pxe_files(self):
+        host = Host.objects.first()
+        self.assertEqual(len(host.as_pxe_files()), 1)

mdb/utils.py

@@ -0,0 +1,82 @@
+import datetime
+from django.conf import settings
+from django.template.loader import render_to_string
+import ipaddress
+import re
+
+
+def format_domain_serial_and_add_one(serial):
+    today = datetime.datetime.now()
+    res = re.findall("^%4d%02d%02d(\d\d)$" % (
+        today.year, today.month, today.day), str(serial), re.DOTALL)
+
+    if len(res) == 0:
+        """ This probably means that the serial is malformed
+        or the date is wrong. We assume that if the date is wrong,
+        it is in the past. Just create a new serial starting from 1."""
+        return "%4d%02d%02d%02d" % \
+            (today.year, today.month, today.day, 1)
+    elif len(res) == 1:
+        """ The serial contains todays date, just update it. """
+        try:
+            number = int(res[0])
+        except:
+            number = 1
+        if number >= 99:
+            """ This is bad... Just keep the number on 99.
+            We also send a mail to sysadmins telling them that
+            something is wrong..."""
+
+        else:
+            number += 1
+        return "%4d%02d%02d%02d" % (
+            today.year, today.month, today.day, number)
+    else:
+        """ Just return the first serial for today. """
+        return "%4d%02d%02d%02d" % \
+            (today.year, today.month, today.day, 1)
+
+
+def render_pxelinux_cfg(_if, host):
+    # TODO add fields to os model and make dynamic per host
+    distro = 'ubuntu/14_04/amd64/alternate/'
+    kernel = distro + 'linux'
+    initrd = distro + 'initrd.gz'
+    preseed_config_url = settings.MDB_PXE_PRESEED_URL
+    context = {
+        'kernel': kernel,
+        'initrd': initrd,
+        'preseed_config_url': preseed_config_url,
+        'host': host,
+        'interface': _if
+    }
+    return render_to_string('pxelinux.cfg', context=context)
+
+
+def get_pxe_filename(interface, filename_format='mac_addr'):
+    """
+    Mac or IP address based PXE filename
+    Ref: http://www.syslinux.org/wiki/index.php/PXELINUX#Examples
+    """
+    ip_addr_in_hex = '{:02X}'.format(int(ipaddress.IPv4Address(interface.ip4address.address)))
+    formats = {
+        'ip_addr': ip_addr_in_hex,
+        'mac_addr': '01-{}'.format(interface.macaddr.lower().replace(':', '-'))
+    }
+
+    return formats.get(filename_format, formats['mac_addr'])
+
+
+def host_as_pxe_files(host):
+    """ Returns a list of filename,content for each host """
+    from mdb.models import Host
+    assert isinstance(host, Host)
+
+    pxe_files = []
+    ifs = host.interface_set.filter(dhcp_client=True)
+    for _if in ifs:
+        filename = get_pxe_filename(_if)
+        content = render_pxelinux_cfg(_if, host)
+        pxe_files.append((filename, content))
+
+    return pxe_files

mdbsite/settings.py

@@ -122,7 +122,10 @@ REST_FRAMEWORK = {
     'PAGINATE_BY': 10
 }
 
+MDB_PXE_TFTP_ROOT = '/var/lib/tftpboot/pxelinux/pxelinux.cfg/'
+MDB_PXE_PRESEED_URL = 'http://158.36.190.194/ubuntu/preseed_1404.cfg'
+
 try:
-    from local_settings import *
+    from .local_settings import *
 except ImportError:
     pass