Merge lp:~jtv/maas/bug-1025582-model into lp:maas/trunk

[Jeroen T. Vermeulen]

New model: BootImage. Represents an available boot image, so that the server can detect use of missing images.

This new model represents what types of node we can boot which releases on, for which purpose. Since the inventory only changes when we have a new image, complete and ready to install, there is no provision for disappearing images.

The master worker (which runs on the same machine as the TFTP server) will report available images regularly through the MAAS API. The download script can't do this directly because it has no API credentials.

Nobody was available to pre-imp this part of the work with, so read critically.

Jeroen

[lp:~jtv/maas/bug-1025582-model]

985. By Jeroen T. Vermeulen on 2012-09-11

Merge trunk workaround for Django fix that broke our tests.

[Raphaël Badin (rvb)]

Looks generally good, but I really wonder about [1], so "needs information".

[0]

src/maasserver/migrations/0021_add_bootimage_model.py

Would you mind renaming this 0025_add_bootimage_model.py? I've recently landed migrations 21 and 22 and I've got branches in review for migrations 23 and 24.

[1]

297 + architecture = CharField(max_length=255, blank=False)
298 + subarchitecture = CharField(max_length=255, blank=False)
299 + release = CharField(max_length=255, blank=False)
300 + purpose = CharField(max_length=255, blank=False)

Why didn't you use CharField with choices here (same as, for instance, node.architecture)?

review: Needs Information

[lp:~jtv/maas/bug-1025582-model]

986. By Jeroen T. Vermeulen on 2012-09-13

Review change: renumber DB migration as newer branches overtake this one in review.

[Jeroen T. Vermeulen (jtv)]

> Looks generally good, but I really wonder about [1], so "needs information".
>
> [0]
>
> src/maasserver/migrations/0021_add_bootimage_model.py
>
> Would you mind renaming this 0025_add_bootimage_model.py? I've recently
> landed migrations 21 and 22 and I've got branches in review for migrations 23
> and 24.

Done.

> [1]
>
> 297 + architecture = CharField(max_length=255, blank=False)
> 298 + subarchitecture = CharField(max_length=255, blank=False)
> 299 + release = CharField(max_length=255, blank=False)
> 300 + purpose = CharField(max_length=255, blank=False)
>
> Why didn't you use CharField with choices here (same as, for instance,
> node.architecture)?

Because I thought that Django might possibly enforce it, which would not be what I wanted: registering available images shouldn't break just because you've got an architecture that the server isn't aware of yet.

But as it turns out the choices option isn't model-related. It's purely for the UI, which this model doesn't have — so probably not worth holding up these reviews for! I added it and made the fields non-editable.

[lp:~jtv/maas/bug-1025582-model]

987. By Jeroen T. Vermeulen on 2012-09-13

Review change: set choices for architecture field.

[Julian Edwards (julian-edwards)]

On Thursday 13 September 2012 03:25:22 you wrote:
> > [1]
> >
> > 297 + architecture = CharField(max_length=255, blank=False)
> > 298 + subarchitecture = CharField(max_length=255, blank=False)
> > 299 + release = CharField(max_length=255, blank=False)
> > 300 + purpose = CharField(max_length=255, blank=False)
> >
> > Why didn't you use CharField with choices here (same as, for instance,
> > node.architecture)?
>
> Because I thought that Django might possibly enforce it, which would not be
> what I wanted: registering available images shouldn't break just because
> you've got an architecture that the server isn't aware of yet.
>
> But as it turns out the choices option isn't model-related. It's purely for
> the UI, which this model doesn't have — so probably not worth holding up
> these reviews for! I added it and made the fields non-editable.

We want to rid the code of all enums for architecture because having one makes
it impossible to install arbitrary new architectures. That is something we
need to support in the near-ish future.

[Julian Edwards (julian-edwards)]

Approved as it was, let's remove the choices.

review: Approve

[lp:~jtv/maas/bug-1025582-model]

988. By Jeroen T. Vermeulen on 2012-09-13

Julian's suggestions.

[Jeroen T. Vermeulen (jtv)]

Thanks. Choices removed, fields documented, propagating changes to successor branches.

[Raphaël Badin (rvb)]

>> [0]
>>
>> src/maasserver/migrations/0021_add_bootimage_model.py
>>
>> Would you mind renaming this 0025_add_bootimage_model.py? I've recently
>> landed migrations 21 and 22 and I've got branches in review for migrations 23
>> and 24.

>Done.

rarg, that was a bad suggestion from me :/. I forgot that each migration not only has information about the delta (what field needs to be added/removed etc.) but also about all of the models. I also spotted a weird (South-related?) problem with the recently uuid field so I'll see about fixing that…

=== added file 'src/maasserver/migrations/0025_add_bootimage_model.py'
--- src/maasserver/migrations/0025_add_bootimage_model.py	1970-01-01 00:00:00 +0000
+++ src/maasserver/migrations/0025_add_bootimage_model.py	2012-09-13 03:54:19 +0000
@@ -0,0 +1,182 @@
+# encoding: utf-8
+import datetime
+
+from django.db import models
+from south.db import db
+from south.v2 import SchemaMigration
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        
+        # Adding model 'BootImage'
+        db.create_table(u'maasserver_bootimage', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('architecture', self.gf('django.db.models.fields.CharField')(max_length=255)),
+            ('subarchitecture', self.gf('django.db.models.fields.CharField')(max_length=255)),
+            ('release', self.gf('django.db.models.fields.CharField')(max_length=255)),
+            ('purpose', self.gf('django.db.models.fields.CharField')(max_length=255)),
+        ))
+        db.send_create_signal(u'maasserver', ['BootImage'])
+
+        # Adding unique constraint on 'BootImage', fields ['architecture', 'subarchitecture', 'release', 'purpose']
+        db.create_unique(u'maasserver_bootimage', ['architecture', 'subarchitecture', 'release', 'purpose'])
+
+
+    def backwards(self, orm):
+        
+        # Removing unique constraint on 'BootImage', fields ['architecture', 'subarchitecture', 'release', 'purpose']
+        db.delete_unique(u'maasserver_bootimage', ['architecture', 'subarchitecture', 'release', 'purpose'])
+
+        # Deleting model 'BootImage'
+        db.delete_table(u'maasserver_bootimage')
+
+
+    models = {
+        'auth.group': {
+            'Meta': {'object_name': 'Group'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'})
+        },
+        'auth.permission': {
+            'Meta': {'ordering': "('content_type__app_label', 'content_type__model', 'codename')", 'unique_together': "(('content_type', 'codename'),)", 'object_name': 'Permission'},
+            'codename': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'content_type': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['contenttypes.ContentType']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
+        },
+        'auth.user': {
+            'Meta': {'object_name': 'User'},
+            'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'email': ('django.db.models.fields.EmailField', [], {'unique': 'True', 'max_length': '75', 'blank': 'True'}),
+            'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'groups': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Group']", 'symmetrical': 'False', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_active': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'is_staff': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'is_superuser': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'last_login': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
+            'last_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
+            'password': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
+            'user_permissions': ('django.db.models.fields.related.ManyToManyField', [], {'to': "orm['auth.Permission']", 'symmetrical': 'False', 'blank': 'True'}),
+            'username': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'})
+        },
+        'contenttypes.contenttype': {
+            'Meta': {'ordering': "('name',)", 'unique_together': "(('app_label', 'model'),)", 'object_name': 'ContentType', 'db_table': "'django_content_type'"},
+            'app_label': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'model': ('django.db.models.fields.CharField', [], {'max_length': '100'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '100'})
+        },
+        u'maasserver.bootimage': {
+            'Meta': {'unique_together': "((u'architecture', u'subarchitecture', u'release', u'purpose'),)", 'object_name': 'BootImage'},
+            'architecture': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'purpose': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'release': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'subarchitecture': ('django.db.models.fields.CharField', [], {'max_length': '255'})
+        },
+        u'maasserver.config': {
+            'Meta': {'object_name': 'Config'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'value': ('maasserver.fields.JSONObjectField', [], {'null': 'True'})
+        },
+        u'maasserver.dhcplease': {
+            'Meta': {'object_name': 'DHCPLease'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'ip': ('django.db.models.fields.IPAddressField', [], {'unique': 'True', 'max_length': '15'}),
+            'mac': ('maasserver.fields.MACAddressField', [], {}),
+            'nodegroup': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['maasserver.NodeGroup']"})
+        },
+        u'maasserver.filestorage': {
+            'Meta': {'object_name': 'FileStorage'},
+            'data': ('django.db.models.fields.files.FileField', [], {'max_length': '255'}),
+            'filename': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '200'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        u'maasserver.macaddress': {
+            'Meta': {'object_name': 'MACAddress'},
+            'created': ('django.db.models.fields.DateTimeField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'mac_address': ('maasserver.fields.MACAddressField', [], {'unique': 'True'}),
+            'node': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['maasserver.Node']"}),
+            'updated': ('django.db.models.fields.DateTimeField', [], {})
+        },
+        u'maasserver.node': {
+            'Meta': {'object_name': 'Node'},
+            'after_commissioning_action': ('django.db.models.fields.IntegerField', [], {'default': '0'}),
+            'architecture': ('django.db.models.fields.CharField', [], {'default': "u'i386'", 'max_length': '10'}),
+            'created': ('django.db.models.fields.DateTimeField', [], {}),
+            'error': ('django.db.models.fields.CharField', [], {'default': "u''", 'max_length': '255', 'blank': 'True'}),
+            'hostname': ('django.db.models.fields.CharField', [], {'default': "u''", 'max_length': '255', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'netboot': ('django.db.models.fields.BooleanField', [], {'default': 'True'}),
+            'nodegroup': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['maasserver.NodeGroup']", 'null': 'True'}),
+            'owner': ('django.db.models.fields.related.ForeignKey', [], {'default': 'None', 'to': "orm['auth.User']", 'null': 'True', 'blank': 'True'}),
+            'power_parameters': ('maasserver.fields.JSONObjectField', [], {'default': "u''", 'blank': 'True'}),
+            'power_type': ('django.db.models.fields.CharField', [], {'default': "u''", 'max_length': '10', 'blank': 'True'}),
+            'status': ('django.db.models.fields.IntegerField', [], {'default': '0', 'max_length': '10'}),
+            'system_id': ('django.db.models.fields.CharField', [], {'default': "u'node-ee3df1b4-fbcb-11e1-8b8f-002608dc6120'", 'unique': 'True', 'max_length': '41'}),
+            'token': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['piston.Token']", 'null': 'True'}),
+            'updated': ('django.db.models.fields.DateTimeField', [], {})
+        },
+        u'maasserver.nodegroup': {
+            'Meta': {'object_name': 'NodeGroup'},
+            'api_key': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '18'}),
+            'api_token': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['piston.Token']", 'unique': 'True'}),
+            'broadcast_ip': ('django.db.models.fields.IPAddressField', [], {'default': "u''", 'max_length': '15', 'null': 'True', 'blank': 'True'}),
+            'created': ('django.db.models.fields.DateTimeField', [], {}),
+            'dhcp_interfaces': ('django.db.models.fields.CharField', [], {'default': "u''", 'max_length': '255', 'blank': 'True'}),
+            'dhcp_key': ('django.db.models.fields.CharField', [], {'default': "u''", 'max_length': '255', 'blank': 'True'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'ip_range_high': ('django.db.models.fields.IPAddressField', [], {'default': "u''", 'max_length': '15', 'unique': 'True', 'null': 'True', 'blank': 'True'}),
+            'ip_range_low': ('django.db.models.fields.IPAddressField', [], {'default': "u''", 'max_length': '15', 'unique': 'True', 'null': 'True', 'blank': 'True'}),
+            'name': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '80'}),
+            'router_ip': ('django.db.models.fields.IPAddressField', [], {'default': "u''", 'max_length': '15', 'null': 'True', 'blank': 'True'}),
+            'subnet_mask': ('django.db.models.fields.IPAddressField', [], {'default': "u''", 'max_length': '15', 'null': 'True', 'blank': 'True'}),
+            'updated': ('django.db.models.fields.DateTimeField', [], {}),
+            'worker_ip': ('django.db.models.fields.IPAddressField', [], {'unique': 'True', 'max_length': '15'})
+        },
+        u'maasserver.sshkey': {
+            'Meta': {'unique_together': "((u'user', u'key'),)", 'object_name': 'SSHKey'},
+            'created': ('django.db.models.fields.DateTimeField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'key': ('django.db.models.fields.TextField', [], {}),
+            'updated': ('django.db.models.fields.DateTimeField', [], {}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']"})
+        },
+        u'maasserver.userprofile': {
+            'Meta': {'object_name': 'UserProfile'},
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'user': ('django.db.models.fields.related.OneToOneField', [], {'to': "orm['auth.User']", 'unique': 'True'})
+        },
+        'piston.consumer': {
+            'Meta': {'object_name': 'Consumer'},
+            'description': ('django.db.models.fields.TextField', [], {}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'key': ('django.db.models.fields.CharField', [], {'max_length': '18'}),
+            'name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'secret': ('django.db.models.fields.CharField', [], {'max_length': '32'}),
+            'status': ('django.db.models.fields.CharField', [], {'default': "'pending'", 'max_length': '16'}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'consumers'", 'null': 'True', 'to': "orm['auth.User']"})
+        },
+        'piston.token': {
+            'Meta': {'object_name': 'Token'},
+            'callback': ('django.db.models.fields.CharField', [], {'max_length': '255', 'null': 'True', 'blank': 'True'}),
+            'callback_confirmed': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'consumer': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['piston.Consumer']"}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'is_approved': ('django.db.models.fields.BooleanField', [], {'default': 'False'}),
+            'key': ('django.db.models.fields.CharField', [], {'max_length': '18'}),
+            'secret': ('django.db.models.fields.CharField', [], {'max_length': '32'}),
+            'timestamp': ('django.db.models.fields.IntegerField', [], {'default': '1347338908L'}),
+            'token_type': ('django.db.models.fields.IntegerField', [], {}),
+            'user': ('django.db.models.fields.related.ForeignKey', [], {'blank': 'True', 'related_name': "'tokens'", 'null': 'True', 'to': "orm['auth.User']"}),
+            'verifier': ('django.db.models.fields.CharField', [], {'max_length': '10'})
+        }
+    }
+
+    complete_apps = ['maasserver']

=== modified file 'src/maasserver/models/__init__.py'
--- src/maasserver/models/__init__.py	2012-08-16 13:38:51 +0000
+++ src/maasserver/models/__init__.py	2012-09-13 03:54:19 +0000
@@ -11,6 +11,7 @@
 
 __metaclass__ = type
 __all__ = [
+    'BootImage',
     'Config',
     'DHCPLease',
     'FileStorage',
@@ -29,6 +30,7 @@
 from django.contrib.auth.models import User
 from django.db.models.signals import post_save
 from maasserver.enum import NODE_PERMISSION
+from maasserver.models.bootimage import BootImage
 from maasserver.models.config import Config
 from maasserver.models.dhcplease import DHCPLease
 from maasserver.models.filestorage import FileStorage
@@ -61,8 +63,9 @@
 
 
 # Register the models in the admin site.
+admin.site.register(BootImage)
+admin.site.register(Config)
 admin.site.register(Consumer)
-admin.site.register(Config)
 admin.site.register(FileStorage)
 admin.site.register(MACAddress)
 admin.site.register(Node)

=== added file 'src/maasserver/models/bootimage.py'
--- src/maasserver/models/bootimage.py	1970-01-01 00:00:00 +0000
+++ src/maasserver/models/bootimage.py	2012-09-13 03:54:19 +0000
@@ -0,0 +1,89 @@
+# Copyright 2012 Canonical Ltd.  This software is licensed under the
+# GNU Affero General Public License version 3 (see the file LICENSE).
+
+"""Registration of available boot images."""
+
+from __future__ import (
+    absolute_import,
+    print_function,
+    unicode_literals,
+    )
+
+__metaclass__ = type
+__all__ = [
+    'BootImage',
+    ]
+
+
+from django.db.models import (
+    CharField,
+    Manager,
+    Model,
+    )
+from maasserver import DefaultMeta
+
+
+class BootImageManager(Manager):
+    """Manager for model class.
+
+    Don't import or instantiate this directly; access as `BootImage.objects`.
+    """
+
+    def get_by_natural_key(self, architecture, subarchitecture, release,
+                           purpose):
+        """Look up a specific image."""
+        return self.get(
+            architecture=architecture, subarchitecture=subarchitecture,
+            release=release, purpose=purpose)
+
+    def register_image(self, architecture, subarchitecture, release, purpose):
+        """Register an image if it wasn't already registered."""
+        self.get_or_create(
+            architecture=architecture, subarchitecture=subarchitecture,
+            release=release, purpose=purpose)
+
+    def have_image(self, architecture, subarchitecture, release, purpose):
+        """Is an image for the given kind of boot available?"""
+        try:
+            self.get_by_natural_key(
+                architecture=architecture, subarchitecture=subarchitecture,
+                release=release, purpose=purpose)
+            return True
+        except BootImage.DoesNotExist:
+            return False
+
+
+class BootImage(Model):
+    """Available boot image (i.e. kernel and initrd).
+
+    Each `BootImage` represents a type of boot for which a boot image is
+    available.  The `maas-import-pxe-files` script imports these, and the
+    TFTP server provides them to booting nodes.
+
+    If a boot image is missing, that may mean that the import script has not
+    been run yet, or has failed; or that it was not configured to provide
+    that particular image.
+
+    Fields correspond directly to values used in the `tftppath` module.
+    """
+
+    class Meta(DefaultMeta):
+        unique_together = (
+            ('architecture', 'subarchitecture', 'release', 'purpose'),
+            )
+
+    objects = BootImageManager()
+
+    # System architecture (e.g. "i386") that the image is for.
+    architecture = CharField(max_length=255, blank=False, editable=False)
+
+    # Sub-architecture, e.g. a particular type of ARM machine that needs
+    # different treatment.  (For architectures that don't need these
+    # such as i386 and amd64, we use "generic").
+    subarchitecture = CharField(max_length=255, blank=False, editable=False)
+
+    # Ubuntu release (e.g. "precise") that the image boots.
+    release = CharField(max_length=255, blank=False, editable=False)
+
+    # Boot purpose (e.g. "commissioning" or "install") that the image is for.
+    purpose = CharField(max_length=255, blank=False, editable=False)

=== modified file 'src/maasserver/testing/factory.py'
--- src/maasserver/testing/factory.py	2012-09-10 14:50:56 +0000
+++ src/maasserver/testing/factory.py	2012-09-13 03:54:19 +0000
@@ -24,6 +24,7 @@
     NODE_STATUS,
     )
 from maasserver.models import (
+    BootImage,
     DHCPLease,
     FileStorage,
     MACAddress,
@@ -271,6 +272,22 @@
         return "OAuth " + ", ".join([
             '%s="%s"' % (key, value) for key, value in items.items()])
 
+    def make_boot_image(self, architecture=None, subarchitecture=None,
+                        release=None, purpose=None):
+        if architecture is None:
+            architecture = self.make_name('architecture')
+        if subarchitecture is None:
+            subarchitecture = self.make_name('subarchitecture')
+        if release is None:
+            release = self.make_name('release')
+        if purpose is None:
+            purpose = self.make_name('purpose')
+        return BootImage.objects.create(
+            architecture=architecture,
+            subarchitecture=subarchitecture,
+            release=release,
+            purpose=purpose)
+
 
 # Create factory singleton.
 factory = Factory()

=== added file 'src/maasserver/tests/test_bootimage.py'
--- src/maasserver/tests/test_bootimage.py	1970-01-01 00:00:00 +0000
+++ src/maasserver/tests/test_bootimage.py	2012-09-13 03:54:19 +0000
@@ -0,0 +1,47 @@
+# Copyright 2012 Canonical Ltd.  This software is licensed under the
+# GNU Affero General Public License version 3 (see the file LICENSE).
+
+"""Tests for :class:`BootImage`."""
+
+from __future__ import (
+    absolute_import,
+    print_function,
+    unicode_literals,
+    )
+
+__metaclass__ = type
+__all__ = []
+
+from maasserver.models import BootImage
+from maasserver.testing.factory import factory
+from maasserver.testing.testcase import TestCase
+
+
+class TestBootImageManager(TestCase):
+
+    def make_image_params(self):
+        return dict(
+            architecture=factory.make_name('architecture'),
+            subarchitecture=factory.make_name('subarchitecture'),
+            release=factory.make_name('release'),
+            purpose=factory.make_name('purpose'))
+
+    def test_have_image_returns_False_if_image_not_available(self):
+        self.assertFalse(
+            BootImage.objects.have_image(**self.make_image_params()))
+
+    def test_have_image_returns_True_if_image_available(self):
+        params = self.make_image_params()
+        factory.make_boot_image(**params)
+        self.assertTrue(BootImage.objects.have_image(**params))
+
+    def test_register_image_registers_new_image(self):
+        params = self.make_image_params()
+        BootImage.objects.register_image(**params)
+        self.assertTrue(BootImage.objects.have_image(**params))
+
+    def test_register_image_leaves_existing_image_intact(self):
+        params = self.make_image_params()
+        factory.make_boot_image(**params)
+        BootImage.objects.register_image(**params)
+        self.assertTrue(BootImage.objects.have_image(**params))