add model support, an API, and a migration for Org -> Galaxy credentials

see: https://github.com/ansible/awx/issues/7813

awx/main/models/credential/__init__.py

@@ -331,6 +331,7 @@ class CredentialType(CommonModelNameNotUnique):
         ('insights', _('Insights')),
         ('external', _('External')),
         ('kubernetes', _('Kubernetes')),
+        ('galaxy', _('Galaxy/Automation Hub')),
     )
 
     kind = models.CharField(
@@ -1173,6 +1174,38 @@ ManagedCredentialType(
 )
 
 
+ManagedCredentialType(
+    namespace='galaxy_api_token',
+    kind='galaxy',
+    name=ugettext_noop('Ansible Galaxy Automation Hub API Token'),
+    inputs={
+        'fields': [{
+            'id': 'url',
+            'label': ugettext_noop('Galaxy Server URL'),
+            'type': 'string',
+            'help_text': ugettext_noop('The URL of the galaxy instance to connect to.')
+        },{
+            'id': 'auth_url',
+            'label': ugettext_noop('Auth Server URL'),
+            'type': 'string',
+            'help_text': ugettext_noop(
+                'The URL of a Keycloak server token_endpoint, if using '
+                'SSO auth.'
+            )
+        },{
+            'id': 'token',
+            'label': ugettext_noop('API Token'),
+            'type': 'string',
+            'secret': True,
+            'help_text': ugettext_noop(
+                'A token to use for authentication against the Galaxy instance.'
+            )
+        }],
+        'required': ['url'],
+    }
+)
+
+
 class CredentialInputSource(PrimordialModel):
 
     class Meta:

awx/main/models/organization.py

@@ -45,6 +45,12 @@ class Organization(CommonModel, NotificationFieldsModel, ResourceMixin, CustomVi
         blank=True,
         through='OrganizationInstanceGroupMembership'
     )
+    galaxy_credentials = OrderedManyToManyField(
+        'Credential',
+        blank=True,
+        through='OrganizationGalaxyCredentialMembership',
+        related_name='%(class)s_galaxy_credentials'
+    )
     max_hosts = models.PositiveIntegerField(
         blank=True,
         default=0,
@@ -108,6 +114,23 @@ class Organization(CommonModel, NotificationFieldsModel, ResourceMixin, CustomVi
         return UnifiedJob.objects.non_polymorphic().filter(organization=self)
 
 
+class OrganizationGalaxyCredentialMembership(models.Model):
+
+    organization = models.ForeignKey(
+        'Organization',
+        on_delete=models.CASCADE
+    )
+    credential = models.ForeignKey(
+        'Credential',
+        on_delete=models.CASCADE
+    )
+    position = models.PositiveIntegerField(
+        null=True,
+        default=None,
+        db_index=True,
+    )
+
+
 class Team(CommonModelNameNotUnique, ResourceMixin):
     '''
     A team is a group of users that work on common projects.