feat(pxe): Add support for PXE config per host/os

mdb/admin.py

@@ -192,7 +192,7 @@ class HostTypeAdmin(admin.ModelAdmin):
 
 
 class OperatingSystemAdmin(admin.ModelAdmin):
-    list_display = ['name', 'version', 'arch']
+    list_display = ['name', 'version', 'arch', 'pxe_kernel', 'pxe_initrd', 'pxe_preseed_config_url']
 
 
 admin.site.register(Domain, DomainAdmin)

mdb/fixtures/test_data.json

@@ -2738,6 +2738,18 @@
     "model": "mdb.operatingsystem",
     "pk": 1
 },
+{
+    "fields": {
+        "pxe_initrd": "path-to-initrd-for-os",
+        "pxe_kernel": "path-to-kernel-for-os",
+        "pxe_preseed_config_url": "http://url-to-preseed.config",
+        "arch": "x86_64",
+        "name": "Ubuntu",
+        "version": "16.04-beta-final"
+    },
+    "model": "mdb.operatingsystem",
+    "pk": 2
+},
 {
     "fields": {
         "kerberos_principal_name": "",

mdb/migrations/0011_auto_20160325_1412.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mdb', '0010_auto_20151004_1709'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='operatingsystem',
+            name='pxe_initrd',
+            field=models.CharField(null=True, blank=True, max_length=255),
+        ),
+        migrations.AddField(
+            model_name='operatingsystem',
+            name='pxe_kernel',
+            field=models.CharField(null=True, blank=True, max_length=255),
+        ),
+        migrations.AddField(
+            model_name='operatingsystem',
+            name='pxe_preseed_config_url',
+            field=models.URLField(null=True, blank=True),
+        ),
+    ]

mdb/models.py

@@ -477,6 +477,10 @@ class OperatingSystem(models.Model):
     version = models.CharField(max_length=64)
     arch = models.CharField(max_length=255, choices=OS_ARCHITECTURES, blank=True, null=True)
 
+    pxe_kernel = models.CharField(max_length=255, blank=True, null=True)
+    pxe_initrd = models.CharField(max_length=255, blank=True, null=True)
+    pxe_preseed_config_url = models.URLField(blank=True, null=True)
+
     def __str__(self):
         return self.name + " " + self.version + " (" + self.arch + ")"
 

mdb/pxe.py

@@ -4,11 +4,21 @@ import ipaddress
 
 
 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'
+    """Renders pxelinux.cfg based on a host and the set of host interfaces.
+    If the host is tied to an OS with PXE fields set, it will use these instead of defaults."""
+    # Default config
+    kernel = settings.MDB_PXE_KERNEL
+    initrd = settings.MDB_PXE_INITRD
     preseed_config_url = settings.MDB_PXE_PRESEED_URL
+
+    # Per host config (via OS model)
+    _os = host.operating_system
+    pxe_attrs = [_os.pxe_initrd, _os.pxe_kernel, _os.pxe_preseed_config_url]
+    if None not in pxe_attrs and '' not in pxe_attrs:
+        kernel = _os.pxe_kernel
+        initrd = _os.pxe_initrd
+        preseed_config_url = _os.pxe_preseed_config_url
+
     context = {
         'kernel': kernel,
         'initrd': initrd,
@@ -16,6 +26,7 @@ def render_pxelinux_cfg(_if, host):
         'host': host,
         'interface': _if
     }
+
     return render_to_string('pxelinux.cfg', context=context)
 
 
@@ -34,7 +45,7 @@ def get_pxe_filename(interface, filename_format='mac_addr'):
 
 
 def host_as_pxe_files(host):
-    """ Returns a list of filename,content for each host interface with an IPv4 address """
+    """Returns a list of filename,content for each host interface with an IPv4 address."""
     from mdb.models import Host
     assert isinstance(host, Host)
 

mdb/tests.py

@@ -1,12 +1,15 @@
 import io
+
+from django.conf import settings
 from django.contrib.auth.models import User
 from django.core.management import call_command
 from django.core.urlresolvers import reverse
 from django.test import TestCase
+from mdb.pxe import render_pxelinux_cfg
 from rest_framework.authtoken.models import Token
 from rest_framework.test import APITestCase
 
-from mdb.models import Host
+from mdb.models import Host, OperatingSystem
 
 
 class MyAPITestCases(APITestCase):
@@ -35,6 +38,27 @@ class MyAPITestCases(APITestCase):
 class UnitTests(TestCase):
     fixtures = ['test_data']
 
+    def test_render_pxeconfig(self):
+        host = Host.objects.first()
+        interface = host.interface_set.exclude(ip4address__isnull=True).first()
+        config = render_pxelinux_cfg(interface, host)
+
+        self.assertIn(settings.MDB_PXE_INITRD, config)
+        self.assertIn(settings.MDB_PXE_KERNEL, config)
+        self.assertIn(settings.MDB_PXE_PRESEED_URL, config)
+
+    def test_render_pxeconfig_with_os_pxe_config(self):
+        _os = OperatingSystem.objects.get(pk=2)  # OS with all pxe vars set
+        Host.objects.filter(pk=Host.objects.first().pk).update(operating_system=_os)
+        host = Host.objects.first()
+
+        interface = host.interface_set.exclude(ip4address__isnull=True).first()
+        config = render_pxelinux_cfg(interface, host)
+
+        self.assertIn(_os.pxe_initrd, config)
+        self.assertIn(_os.pxe_kernel, config)
+        self.assertIn(_os.pxe_preseed_config_url, config)
+
     def test_host_as_pxe_files(self):
         host = Host.objects.first()
         self.assertEqual(len(host.as_pxe_files()), 1)

mdbsite/settings.py

@@ -124,6 +124,8 @@ REST_FRAMEWORK = {
 }
 
 MDB_PXE_TFTP_ROOT = '/var/lib/tftpboot/pxelinux/pxelinux.cfg/'
+MDB_PXE_KERNEL = 'ubuntu/14_04/amd64/alternate/linux'
+MDB_PXE_INITRD = 'ubuntu/14_04/amd64/alternate/initrd.gz'
 MDB_PXE_PRESEED_URL = 'http://158.36.190.194/ubuntu/preseed_1404.cfg'
 
 try: