Merge lp:~julian-edwards/maas/dup-boot-source-selections-part2-bug-1360280 into lp:~maas-committers/maas/trunk

[Julian Edwards]

Validate BootSourceSelection changes against the available selection that lives in BootSourceCache. Previously, bogus entries could be added.

Whoever reviews this, please double check that this won't affect custom images. I don't think it will, but ...

[Graham Binns (gmb)]

Looks good. There's a don't-make-me-think nit inline, but otherwise this is fine.

review: Approve

[Julian Edwards (julian-edwards)]

On Wednesday 12 Nov 2014 07:37:38 you wrote:
> I can *hear* jtv, here and elsewhere, saying "What is this obsession with
> creating 3 _things_?"

Arf :)

> Also, I don't actually understand from the test why you're creating three
> mostly identical BootSourceCaches, here and elsewhere. What does it
> actually achieve? Wouldn't one do just as well?

You figured this out....

> > + boot_caches.append(factory.make_BootSourceCache(
> > + boot_source, arch=factory.make_name('arch'),
> > + os=os, release=release))
> > +
> > + params = {
> > + 'os': os,
> > + 'release': release,
> > + 'arches': [boot_caches[0].arch, boot_caches[2].arch],
>
> Ah, I get it now; you're combining the valid values for the field you're
> testing on from some but not all of the BootSourceCaches you've created.
>
> Consider moving the for loop into a helper. Also, add a comment (or a
> docstring on the helper so that you're not having to C&P comments all over
> the shop) explaining why you're creating multiple BootSourceCaches and what
> they'll be used for.

I've been staring at the code for so long that it didn't look that bad any
more. I guess I'll try for a helper - I ran out of brain juice on this one.

Thanks for reviewing!

[MAAS Lander (maas-lander)]

The attempt to merge lp:~julian-edwards/maas/dup-boot-source-selections-part2-bug-1360280 into lp:maas failed. Below is the output from the failed tests.

Ign http://security.ubuntu.com trusty-security InRelease
Get:1 http://security.ubuntu.com trusty-security Release.gpg [933 B]
Ign http://nova.clouds.archive.ubuntu.com trusty InRelease
Get:2 http://security.ubuntu.com trusty-security Release [62.0 kB]
Ign http://nova.clouds.archive.ubuntu.com trusty-updates InRelease
Hit http://nova.clouds.archive.ubuntu.com trusty Release.gpg
Get:3 http://nova.clouds.archive.ubuntu.com trusty-updates Release.gpg [933 B]
Hit http://nova.clouds.archive.ubuntu.com trusty Release
Get:4 http://nova.clouds.archive.ubuntu.com trusty-updates Release [62.0 kB]
Get:5 http://security.ubuntu.com trusty-security/main Sources [49.5 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty/main Sources
Get:6 http://security.ubuntu.com trusty-security/universe Sources [13.1 kB]
Get:7 http://security.ubuntu.com trusty-security/main amd64 Packages [153 kB]
Get:8 http://security.ubuntu.com trusty-security/universe amd64 Packages [60.5 kB]
Hit http://security.ubuntu.com trusty-security/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Sources
Hit http://security.ubuntu.com trusty-security/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en
Get:9 http://nova.clouds.archive.ubuntu.com trusty-updates/main Sources [136 kB]
Get:10 http://nova.clouds.archive.ubuntu.com trusty-updates/universe Sources [89.5 kB]
Get:11 http://nova.clouds.archive.ubuntu.com trusty-updates/main amd64 Packages [356 kB]
Get:12 http://nova.clouds.archive.ubuntu.com trusty-updates/universe amd64 Packages [217 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Translation-en
Ign http://nova.clouds.archive.ubuntu.com trusty/main Translation-en_US
Ign http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en_US
Fetched 1,200 kB in 2s (411 kB/s)
Reading package lists...
sudo DEBIAN_FRONTEND=noninteractive apt-get -y \
     --no-install-recommends install apache2 authbind bind9 bind9utils build-essential bzr-builddeb curl daemontools debhelper dh-apport distro-info dnsutils firefox freeipmi-tools gjs ipython isc-dhcp-common libjs-raphael libjs-yui3-full libjs-yui3-min libpq-dev make pep8 postgresql pyflakes python-amqplib python-bzrlib python-celery python-convoy python-crochet python-cssselect python-curtin python-dev python-distro-info python-django python-django-piston python-django-south python-djorm-ext-pgarray python-docutils python-extras python-fixtures python-flake8 python-formencode python-hivex python-httplib2 python-jinja2 python-jsonschema python-lockfile python-lxml python-mimeparse python-mock python-netaddr python-netifaces python-nose python-oauth python-oops python-oops-amqp python-oops-datedir-repo python-oops-twi...

[Julian Edwards (julian-edwards)]

Thanks for pushing me to write a helper Graham, it was needed in the API tests that had become broken because of the extra validation!

[MAAS Lander (maas-lander)]

The attempt to merge lp:~julian-edwards/maas/dup-boot-source-selections-part2-bug-1360280 into lp:maas failed. Below is the output from the failed tests.

Ign http://security.ubuntu.com trusty-security InRelease
Get:1 http://security.ubuntu.com trusty-security Release.gpg [933 B]
Ign http://nova.clouds.archive.ubuntu.com trusty InRelease
Get:2 http://security.ubuntu.com trusty-security Release [62.0 kB]
Ign http://nova.clouds.archive.ubuntu.com trusty-updates InRelease
Hit http://nova.clouds.archive.ubuntu.com trusty Release.gpg
Get:3 http://nova.clouds.archive.ubuntu.com trusty-updates Release.gpg [933 B]
Hit http://nova.clouds.archive.ubuntu.com trusty Release
Get:4 http://nova.clouds.archive.ubuntu.com trusty-updates Release [62.0 kB]
Get:5 http://security.ubuntu.com trusty-security/main Sources [49.5 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty/main Sources
Get:6 http://security.ubuntu.com trusty-security/universe Sources [13.1 kB]
Get:7 http://security.ubuntu.com trusty-security/main amd64 Packages [153 kB]
Get:8 http://security.ubuntu.com trusty-security/universe amd64 Packages [60.5 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/main amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en
Get:9 http://nova.clouds.archive.ubuntu.com trusty-updates/main Sources [136 kB]
Hit http://security.ubuntu.com trusty-security/main Translation-en
Hit http://security.ubuntu.com trusty-security/universe Translation-en
Get:10 http://nova.clouds.archive.ubuntu.com trusty-updates/universe Sources [89.5 kB]
Get:11 http://nova.clouds.archive.ubuntu.com trusty-updates/main amd64 Packages [356 kB]
Get:12 http://nova.clouds.archive.ubuntu.com trusty-updates/universe amd64 Packages [217 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Translation-en
Ign http://nova.clouds.archive.ubuntu.com trusty/main Translation-en_US
Ign http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en_US
Fetched 1,200 kB in 2s (411 kB/s)
Reading package lists...
sudo DEBIAN_FRONTEND=noninteractive apt-get -y \
     --no-install-recommends install apache2 authbind bind9 bind9utils build-essential bzr-builddeb curl daemontools debhelper dh-apport distro-info dnsutils firefox freeipmi-tools gjs ipython isc-dhcp-common libjs-raphael libjs-yui3-full libjs-yui3-min libpq-dev make pep8 postgresql pyflakes python-amqplib python-bzrlib python-celery python-convoy python-crochet python-cssselect python-curtin python-dev python-distro-info python-django python-django-piston python-django-south python-djorm-ext-pgarray python-docutils python-extras python-fixtures python-flake8 python-formencode python-hivex python-httplib2 python-jinja2 python-jsonschema python-lockfile python-lxml python-mimeparse python-mock python-netaddr python-netifaces python-nose python-oauth python-oops python-oops-amqp python-oops-datedir-repo python-oops-twi...

[MAAS Lander (maas-lander)]

The attempt to merge lp:~julian-edwards/maas/dup-boot-source-selections-part2-bug-1360280 into lp:maas failed. Below is the output from the failed tests.

Ign http://security.ubuntu.com trusty-security InRelease
Get:1 http://security.ubuntu.com trusty-security Release.gpg [933 B]
Get:2 http://security.ubuntu.com trusty-security Release [62.0 kB]
Ign http://nova.clouds.archive.ubuntu.com trusty InRelease
Ign http://nova.clouds.archive.ubuntu.com trusty-updates InRelease
Hit http://nova.clouds.archive.ubuntu.com trusty Release.gpg
Get:3 http://nova.clouds.archive.ubuntu.com trusty-updates Release.gpg [933 B]
Hit http://nova.clouds.archive.ubuntu.com trusty Release
Get:4 http://nova.clouds.archive.ubuntu.com trusty-updates Release [62.0 kB]
Get:5 http://security.ubuntu.com trusty-security/main Sources [49.5 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty/main Sources
Get:6 http://security.ubuntu.com trusty-security/universe Sources [13.1 kB]
Get:7 http://security.ubuntu.com trusty-security/main amd64 Packages [153 kB]
Get:8 http://security.ubuntu.com trusty-security/universe amd64 Packages [60.5 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Sources
Hit http://nova.clouds.archive.ubuntu.com trusty/main amd64 Packages
Hit http://security.ubuntu.com trusty-security/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe amd64 Packages
Hit http://nova.clouds.archive.ubuntu.com trusty/main Translation-en
Hit http://security.ubuntu.com trusty-security/universe Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en
Get:9 http://nova.clouds.archive.ubuntu.com trusty-updates/main Sources [136 kB]
Get:10 http://nova.clouds.archive.ubuntu.com trusty-updates/universe Sources [89.5 kB]
Get:11 http://nova.clouds.archive.ubuntu.com trusty-updates/main amd64 Packages [356 kB]
Get:12 http://nova.clouds.archive.ubuntu.com trusty-updates/universe amd64 Packages [217 kB]
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/main Translation-en
Hit http://nova.clouds.archive.ubuntu.com trusty-updates/universe Translation-en
Ign http://nova.clouds.archive.ubuntu.com trusty/main Translation-en_US
Ign http://nova.clouds.archive.ubuntu.com trusty/universe Translation-en_US
Fetched 1,200 kB in 2s (418 kB/s)
Reading package lists...
sudo DEBIAN_FRONTEND=noninteractive apt-get -y \
     --no-install-recommends install apache2 authbind bind9 bind9utils build-essential bzr-builddeb curl daemontools debhelper dh-apport distro-info dnsutils firefox freeipmi-tools gjs ipython isc-dhcp-common libjs-raphael libjs-yui3-full libjs-yui3-min libpq-dev make pep8 postgresql pyflakes python-amqplib python-bzrlib python-celery python-convoy python-crochet python-cssselect python-curtin python-dev python-distro-info python-django python-django-piston python-django-south python-djorm-ext-pgarray python-docutils python-extras python-fixtures python-flake8 python-formencode python-hivex python-httplib2 python-jinja2 python-jsonschema python-lockfile python-lxml python-mimeparse python-mock python-netaddr python-netifaces python-nose python-oauth python-oops python-oops-amqp python-oops-datedir-repo python-oops-twi...

[Julian Edwards (julian-edwards)]

It would help if I remembered to push my changes up.

=== modified file 'src/maasserver/api/tests/test_boot_source_selections.py'
--- src/maasserver/api/tests/test_boot_source_selections.py	2014-10-23 15:26:37 +0000
+++ src/maasserver/api/tests/test_boot_source_selections.py	2014-11-13 03:13:37 +0000
@@ -117,17 +117,20 @@
         boot_source_selection = factory.make_BootSourceSelection()
         new_os = factory.make_name('os')
         new_release = factory.make_name('release')
+        boot_source_caches = factory.make_many_BootSourceCaches(
+            2, boot_source=boot_source_selection.boot_source, os=new_os,
+            release=new_release)
         new_values = {
             'os': new_os,
             'release': new_release,
-            'arches': [factory.make_name('arch'), factory.make_name('arch')],
+            'arches': [boot_source_caches[0].arch, boot_source_caches[1].arch],
             'subarches': [
-                factory.make_name('subarch'), factory.make_name('subarch')],
-            'labels': [factory.make_name('label')],
+                boot_source_caches[0].subarch, boot_source_caches[1].subarch],
+            'labels': [boot_source_caches[0].label],
         }
         response = self.client_put(
             get_boot_source_selection_uri(boot_source_selection), new_values)
-        self.assertEqual(httplib.OK, response.status_code)
+        self.assertEqual(httplib.OK, response.status_code, response.content)
         boot_source_selection = reload_object(boot_source_selection)
         self.assertAttributes(boot_source_selection, new_values)
 
@@ -216,12 +219,15 @@
         self.become_admin()
         boot_source_selection = factory.make_BootSourceSelection()
         new_release = factory.make_name('release')
+        boot_source_caches = factory.make_many_BootSourceCaches(
+            2, boot_source=boot_source_selection.boot_source,
+            release=new_release)
         new_values = {
             'release': new_release,
-            'arches': [factory.make_name('arch'), factory.make_name('arch')],
+            'arches': [boot_source_caches[0].arch, boot_source_caches[1].arch],
             'subarches': [
-                factory.make_name('subarch'), factory.make_name('subarch')],
-            'labels': [factory.make_name('label')],
+                boot_source_caches[0].subarch, boot_source_caches[1].subarch],
+            'labels': [boot_source_caches[0].label],
         }
         response = self.client_put(
             get_boot_source_selection_backward_uri(
@@ -279,12 +285,15 @@
         self.become_admin()
         boot_source = factory.make_BootSource()
         new_release = factory.make_name('release')
+        boot_source_caches = factory.make_many_BootSourceCaches(
+            2, boot_source=boot_source,
+            release=new_release)
         params = {
             'release': new_release,
-            'arches': [factory.make_name('arch'), factory.make_name('arch')],
+            'arches': [boot_source_caches[0].arch, boot_source_caches[1].arch],
             'subarches': [
-                factory.make_name('subarch'), factory.make_name('subarch')],
-            'labels': [factory.make_name('label')],
+                boot_source_caches[0].subarch, boot_source_caches[1].subarch],
+            'labels': [boot_source_caches[0].label],
         }
         response = self.client.post(
             reverse(
@@ -373,12 +382,14 @@
         self.become_admin()
         boot_source = factory.make_BootSource()
         new_release = factory.make_name('release')
+        boot_source_caches = factory.make_many_BootSourceCaches(
+            2, boot_source=boot_source, release=new_release)
         params = {
             'release': new_release,
-            'arches': [factory.make_name('arch'), factory.make_name('arch')],
+            'arches': [boot_source_caches[0].arch, boot_source_caches[1].arch],
             'subarches': [
-                factory.make_name('subarch'), factory.make_name('subarch')],
-            'labels': [factory.make_name('label')],
+                boot_source_caches[0].subarch, boot_source_caches[1].subarch],
+            'labels': [boot_source_caches[0].label],
         }
         response = self.client.post(self.get_uri(boot_source), params)
         self.assertEqual(httplib.OK, response.status_code)

=== modified file 'src/maasserver/forms.py'
--- src/maasserver/forms.py	2014-11-07 15:33:47 +0000
+++ src/maasserver/forms.py	2014-11-13 03:13:37 +0000
@@ -109,6 +109,7 @@
     BootResourceFile,
     BootResourceSet,
     BootSource,
+    BootSourceCache,
     BootSourceSelection,
     Config,
     DownloadProgress,
@@ -2354,6 +2355,61 @@
         else:
             self.boot_source = boot_source
 
+    def clean(self):
+        cleaned_data = super(BootSourceSelectionForm, self).clean()
+
+        # Don't filter on OS if not provided. This is to maintain
+        # backwards compatibility for when OS didn't exist in the API.
+        if cleaned_data['os']:
+            cache = BootSourceCache.objects.filter(
+                boot_source=self.boot_source, os=cleaned_data['os'],
+                release=cleaned_data['release'])
+        else:
+            cache = BootSourceCache.objects.filter(
+                boot_source=self.boot_source, release=cleaned_data['release'])
+
+        if not cache.exists():
+            set_form_error(
+                self, "os",
+                "OS %s with release %s has no available images for download" %
+                (cleaned_data['os'], cleaned_data['release']))
+            return cleaned_data
+
+        values = cache.values_list("arch", "subarch", "label")
+        arches, subarches, labels = zip(*values)
+
+        # Validate architectures.
+        required_arches_set = set(arch for arch in cleaned_data['arches'])
+        wildcard_arches = '*' in required_arches_set
+        if not wildcard_arches and not required_arches_set <= set(arches):
+            set_form_error(
+                self, "arches",
+                "No available images to download for %s" %
+                cleaned_data['arches'])
+
+        # Validate subarchitectures.
+        required_subarches_set = set(sa for sa in cleaned_data['subarches'])
+        wildcard_subarches = '*' in required_subarches_set
+        if (
+            not wildcard_subarches and
+            not required_subarches_set <= set(subarches)
+                ):
+            set_form_error(
+                self, "subarches",
+                "No available images to download for %s" %
+                cleaned_data['subarches'])
+
+        # Validate labels.
+        required_labels_set = set(label for label in cleaned_data['labels'])
+        wildcard_labels = '*' in required_labels_set
+        if not wildcard_labels and not required_labels_set <= set(labels):
+            set_form_error(
+                self, "labels",
+                "No available images to download for %s" %
+                cleaned_data['labels'])
+
+        return cleaned_data
+
     def save(self, *args, **kwargs):
         boot_source_selection = super(
             BootSourceSelectionForm, self).save(commit=False)

=== modified file 'src/maasserver/testing/factory.py'
--- src/maasserver/testing/factory.py	2014-11-07 16:54:51 +0000
+++ src/maasserver/testing/factory.py	2014-11-13 03:13:37 +0000
@@ -891,6 +891,12 @@
             boot_source=boot_source, os=os, arch=arch,
             subarch=subarch, release=release, label=label)
 
+    def make_many_BootSourceCaches(self, number, **kwargs):
+        caches = list()
+        for _ in range(number):
+            caches.append(self.make_BootSourceCache(**kwargs))
+        return caches
+
     def make_BootSourceSelection(self, boot_source=None, os=None,
                                  release=None, arches=None, subarches=None,
                                  labels=None):

=== modified file 'src/maasserver/tests/test_forms_bootsourceselection.py'
--- src/maasserver/tests/test_forms_bootsourceselection.py	2014-11-11 05:15:23 +0000
+++ src/maasserver/tests/test_forms_bootsourceselection.py	2014-11-13 03:13:37 +0000
@@ -24,16 +24,47 @@
 class TestBootSourceSelectionForm(MAASServerTestCase):
     """Tests for `BootSourceSelectionForm`."""
 
+    def make_valid_source_selection_params(self, boot_source=None):
+        # Helper that creates a valid BootSourceCache and parameters for
+        # a BootSourceSelectionForm that will validate against the
+        # cache.
+        if boot_source is None:
+            boot_source = factory.make_BootSource()
+        arch = factory.make_name('arch')
+        arch2 = factory.make_name('arch')
+        subarch = factory.make_name('subarch')
+        subarch2 = factory.make_name('subarch')
+        label = factory.make_name('label')
+        label2 = factory.make_name('label')
+        params = {
+            'os': factory.make_name('os'),
+            'release': factory.make_name('release'),
+            'arches': [arch, arch2],
+            'subarches': [subarch, subarch2],
+            'labels': [label, label2],
+        }
+        factory.make_BootSourceCache(
+            boot_source=boot_source,
+            os=params['os'],
+            release=params['release'],
+            arch=arch,
+            subarch=subarch,
+            label=label,
+            )
+        factory.make_BootSourceCache(
+            boot_source=boot_source,
+            os=params['os'],
+            release=params['release'],
+            arch=arch2,
+            subarch=subarch2,
+            label=label2,
+            )
+        return params
+
     def test_edits_boot_source_selection_object(self):
         boot_source_selection = factory.make_BootSourceSelection()
-        params = {
-            'os': factory.make_name('os'),
-            'release': factory.make_name('release'),
-            'arches': [factory.make_name('arch'), factory.make_name('arch')],
-            'subarches': [
-                factory.make_name('subarch'), factory.make_name('subarch')],
-            'labels': [factory.make_name('label'), factory.make_name('label')],
-        }
+        boot_source = boot_source_selection.boot_source
+        params = self.make_valid_source_selection_params(boot_source)
         form = BootSourceSelectionForm(
             instance=boot_source_selection, data=params)
         self.assertTrue(form.is_valid(), form._errors)
@@ -43,14 +74,7 @@
 
     def test_creates_boot_source_selection_object(self):
         boot_source = factory.make_BootSource()
-        params = {
-            'os': factory.make_name('os'),
-            'release': factory.make_name('release'),
-            'arches': [factory.make_name('arch'), factory.make_name('arch')],
-            'subarches': [
-                factory.make_name('subarch'), factory.make_name('subarch')],
-            'labels': [factory.make_name('label'), factory.make_name('label')],
-        }
+        params = self.make_valid_source_selection_params(boot_source)
         form = BootSourceSelectionForm(boot_source=boot_source, data=params)
         self.assertTrue(form.is_valid(), form._errors)
         boot_source_selection = form.save()
@@ -58,15 +82,9 @@
 
     def test_cannot_create_duplicate_entry(self):
         boot_source = factory.make_BootSource()
-        params = {
-            'os': factory.make_name('os'),
-            'release': factory.make_name('release'),
-            'arches': [factory.make_name('arch'), factory.make_name('arch')],
-            'subarches': [
-                factory.make_name('subarch'), factory.make_name('subarch')],
-            'labels': [factory.make_name('label'), factory.make_name('label')],
-        }
-        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        params = self.make_valid_source_selection_params(boot_source)
+        form = BootSourceSelectionForm(
+            boot_source=boot_source, data=params)
         self.assertTrue(form.is_valid(), form._errors)
         form.save()
 
@@ -79,3 +97,195 @@
         form = BootSourceSelectionForm(
             boot_source=boot_source, data=dup_params)
         self.assertRaises(ValidationError, form.save)
+
+    def test_validates_if_boot_source_cache_has_same_os_and_release(self):
+        boot_source = factory.make_BootSource()
+        boot_cache = factory.make_BootSourceCache(boot_source)
+
+        params = {
+            'os': boot_cache.os,
+            'release': boot_cache.release,
+        }
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertTrue(form.is_valid(), form._errors)
+
+    def test_rejects_if_boot_source_cache_has_different_os(self):
+        boot_source = factory.make_BootSource()
+        boot_cache = factory.make_BootSourceCache(boot_source)
+
+        params = {
+            'os': factory.make_name('os'),
+            'release': boot_cache.release,
+        }
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            {
+                "os": [
+                    "OS %s with release %s has no available images "
+                    "for download" % (params['os'], boot_cache.release)
+                ]
+            },
+            form._errors)
+
+    def test_rejects_if_boot_source_cache_has_different_release(self):
+        boot_source = factory.make_BootSource()
+        boot_cache = factory.make_BootSourceCache(boot_source)
+
+        params = {
+            'os': boot_cache.os,
+            'release': factory.make_name('release'),
+        }
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            {
+                "os": [
+                    "OS %s with release %s has no available images "
+                    "for download" % (boot_cache.os, params['release'])
+                ]
+            },
+            form._errors)
+
+    def make_some_caches(self, boot_source, os, release):
+        # Make a few BootSourceCache records that the following tests can use
+        # to validate against when using BootSourceSelectionForm.
+        return factory.make_many_BootSourceCaches(
+            3, boot_source=boot_source, os=os, release=release)
+
+    def test_validates_if_boot_source_cache_has_arch(self):
+        boot_source = factory.make_BootSource()
+        os = factory.make_name('os')
+        release = factory.make_name('release')
+        boot_caches = self.make_some_caches(boot_source, os, release)
+
+        # Request arches that are in two of the cache records.
+        params = {
+            'os': os,
+            'release': release,
+            'arches': [boot_caches[0].arch, boot_caches[2].arch],
+        }
+
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertTrue(form.is_valid(), form._errors)
+
+    def test_rejects_if_boot_source_cache_does_not_have_arch(self):
+        boot_source = factory.make_BootSource()
+        os = factory.make_name('os')
+        release = factory.make_name('release')
+        factory.make_BootSourceCache(
+            boot_source, os=os, release=release)
+
+        params = {
+            'os': os,
+            'release': release,
+            'arches': [factory.make_name('arch')],
+        }
+
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            {
+                "arches": [
+                    "No available images to download for %s" %
+                    params['arches']
+                ]
+            },
+            form._errors)
+
+    def test_validates_if_boot_source_cache_has_subarch(self):
+        boot_source = factory.make_BootSource()
+        os = factory.make_name('os')
+        release = factory.make_name('release')
+        boot_caches = self.make_some_caches(boot_source, os, release)
+
+        # Request subarches that are in two of the cache records.
+        params = {
+            'os': os,
+            'release': release,
+            'subarches': [boot_caches[0].subarch, boot_caches[2].subarch],
+        }
+
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertTrue(form.is_valid(), form._errors)
+
+    def test_rejects_if_boot_source_cache_does_not_have_subarch(self):
+        boot_source = factory.make_BootSource()
+        os = factory.make_name('os')
+        release = factory.make_name('release')
+        factory.make_BootSourceCache(
+            boot_source, os=os, release=release)
+
+        params = {
+            'os': os,
+            'release': release,
+            'subarches': [factory.make_name('subarch')],
+        }
+
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            {
+                "subarches": [
+                    "No available images to download for %s" %
+                    params['subarches']
+                ]
+            },
+            form._errors)
+
+    def test_validates_if_boot_source_cache_has_label(self):
+        boot_source = factory.make_BootSource()
+        os = factory.make_name('os')
+        release = factory.make_name('release')
+        boot_caches = self.make_some_caches(boot_source, os, release)
+
+        # Request labels that are in two of the cache records.
+        params = {
+            'os': os,
+            'release': release,
+            'labels': [boot_caches[0].label, boot_caches[2].label],
+        }
+
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertTrue(form.is_valid(), form._errors)
+
+    def test_rejects_if_boot_source_cache_does_not_have_label(self):
+        boot_source = factory.make_BootSource()
+        os = factory.make_name('os')
+        release = factory.make_name('release')
+        factory.make_BootSourceCache(
+            boot_source, os=os, release=release)
+
+        params = {
+            'os': os,
+            'release': release,
+            'labels': [factory.make_name('label')],
+        }
+
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertFalse(form.is_valid())
+        self.assertEqual(
+            {
+                "labels": [
+                    "No available images to download for %s" %
+                    params['labels']
+                ]
+            },
+            form._errors)
+
+    def test_star_values_in_request_validate_against_any_cache(self):
+        boot_source = factory.make_BootSource()
+        os = factory.make_name('os')
+        release = factory.make_name('release')
+        factory.make_BootSourceCache(
+            boot_source, os=os, release=release)
+        params = {
+            'os': os,
+            'release': release,
+            'arches': ['*'],
+            'subarches': ['*'],
+            'labels': ['*'],
+        }
+
+        form = BootSourceSelectionForm(boot_source=boot_source, data=params)
+        self.assertTrue(form.is_valid(), form._errors)