fix(controller): specify dicts as defaults and guard against old errors

We should have been initializing our JSONFields with dict objects, not
strings. Also upgrading from a slightly earlier version of Deis to this
change could hit a JSON encoding error, so catch that and use the chance
to clean up the data. Also reverted the unnecessary workaround of
subclassing JSONField.

Author: mboersma

controller/api/fields.py

@@ -8,22 +8,6 @@
 from django import forms
 from django.db import models
 
-import json_field
-
-
-class JSONField(json_field.JSONField):
-
-    """
-    A subclass of json_field.JSONField that fixes empty JSON object
-    encoding behavior.
-    """
-
-    def get_db_prep_value(self, value, *args, **kwargs):
-        # if it's one of these values, it's already encoded
-        if value in ['{}', '[]']:
-            return value
-        return super(JSONField, self).get_db_prep_value(value, *args, **kwargs)
-
 
 class UuidField(models.CharField):
     """A univerally unique ID field."""

controller/api/models.py

@@ -21,6 +21,7 @@
 from django.utils.encoding import python_2_unicode_compatible
 from django_fsm import FSMField, transition
 from django_fsm.signals import post_transition
+from json_field.fields import JSONField
 
 from api import fields, tasks
 from registry import publish_release
@@ -87,7 +88,7 @@ class Cluster(UuidAuditedModel):
     domain = models.CharField(max_length=128)
     hosts = models.CharField(max_length=256)
     auth = models.TextField()
-    options = fields.JSONField(default='{}', blank=True)
+    options = JSONField(default={}, blank=True)
 
     def __str__(self):
         return self.id
@@ -122,7 +123,7 @@ class App(UuidAuditedModel):
     owner = models.ForeignKey(settings.AUTH_USER_MODEL)
     id = models.SlugField(max_length=64, unique=True)
     cluster = models.ForeignKey('Cluster')
-    structure = fields.JSONField(default='{}', blank=True)
+    structure = JSONField(default={}, blank=True)
 
     class Meta:
         permissions = (('use_app', 'Can use app'),)
@@ -135,7 +136,7 @@ def url(self):
         return self.id + '.' + self.cluster.domain
 
     def create(self, *args, **kwargs):
-        config = Config.objects.create(owner=self.owner, app=self, values={})
+        config = Config.objects.create(owner=self.owner, app=self)
         build = Build.objects.create(owner=self.owner, app=self, image=settings.DEFAULT_BUILD)
         Release.objects.create(version=1, owner=self.owner, app=self, config=config, build=build)
 
@@ -407,7 +408,7 @@ class Build(UuidAuditedModel):
 
     # optional fields populated by builder
     sha = models.CharField(max_length=40, blank=True)
-    procfile = fields.JSONField(default='{}', blank=True)
+    procfile = JSONField(default={}, blank=True)
     dockerfile = models.TextField(blank=True)
 
     class Meta:
@@ -428,9 +429,9 @@ class Config(UuidAuditedModel):
 
     owner = models.ForeignKey(settings.AUTH_USER_MODEL)
     app = models.ForeignKey('App')
-    values = fields.JSONField(default='{}', blank=True)
-    memory = fields.JSONField(default='{}', blank=True)
-    cpu = fields.JSONField(default='{}', blank=True)
+    values = JSONField(default={}, blank=True)
+    memory = JSONField(default={}, blank=True)
+    cpu = JSONField(default={}, blank=True)
 
     class Meta:
         get_latest_by = 'created'

controller/api/south_migrations/0013_auto__del_limit__del_unique_limit_app_uuid__del_field_config_limit__ad.py

@@ -19,12 +19,12 @@ def forwards(self, orm):
 
         # Adding field 'Config.memory'
         db.add_column(u'api_config', 'memory',
-                      self.gf('json_field.fields.JSONField')(default=u'{}', blank=True),
+                      self.gf('json_field.fields.JSONField')(default={}, blank=True),
                       keep_default=False)
 
         # Adding field 'Config.cpu'
         db.add_column(u'api_config', 'cpu',
-                      self.gf('json_field.fields.JSONField')(default=u'{}', blank=True),
+                      self.gf('json_field.fields.JSONField')(default={}, blank=True),
                       keep_default=False)
 
 
@@ -63,7 +63,7 @@ def backwards(self, orm):
             'created': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
             'id': ('django.db.models.fields.SlugField', [], {'unique': 'True', 'max_length': '64'}),
             'owner': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['auth.User']"}),
-            'structure': ('json_field.fields.JSONField', [], {'default': "u'{}'", 'blank': 'True'}),
+            'structure': ('json_field.fields.JSONField', [], {'default': '{}', 'blank': 'True'}),
             'updated': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'blank': 'True'}),
             'uuid': ('api.fields.UuidField', [], {'unique': 'True', 'max_length': '32', 'primary_key': 'True'})
         },
@@ -74,7 +74,7 @@ def backwards(self, orm):
             'dockerfile': ('django.db.models.fields.TextField', [], {'blank': 'True'}),
             'image': ('django.db.models.fields.CharField', [], {'max_length': '256'}),
             'owner': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['auth.User']"}),
-            'procfile': ('json_field.fields.JSONField', [], {'default': "u'{}'", 'blank': 'True'}),
+            'procfile': ('json_field.fields.JSONField', [], {'default': '{}', 'blank': 'True'}),
             'sha': ('django.db.models.fields.CharField', [], {'max_length': '40', 'blank': 'True'}),
             'updated': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'blank': 'True'}),
             'uuid': ('api.fields.UuidField', [], {'unique': 'True', 'max_length': '32', 'primary_key': 'True'})
@@ -86,7 +86,7 @@ def backwards(self, orm):
             'domain': ('django.db.models.fields.CharField', [], {'max_length': '128'}),
             'hosts': ('django.db.models.fields.CharField', [], {'max_length': '256'}),
             'id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '128'}),
-            'options': ('json_field.fields.JSONField', [], {'default': "u'{}'", 'blank': 'True'}),
+            'options': ('json_field.fields.JSONField', [], {'default': '{}', 'blank': 'True'}),
             'owner': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['auth.User']"}),
             'type': ('django.db.models.fields.CharField', [], {'default': "u'coreos'", 'max_length': '16'}),
             'updated': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'blank': 'True'}),
@@ -95,13 +95,13 @@ def backwards(self, orm):
         u'api.config': {
             'Meta': {'ordering': "[u'-created']", 'unique_together': "((u'app', u'uuid'),)", 'object_name': 'Config'},
             'app': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['api.App']"}),
-            'cpu': ('json_field.fields.JSONField', [], {'default': "u'{}'", 'blank': 'True'}),
+            'cpu': ('json_field.fields.JSONField', [], {'default': '{}', 'blank': 'True'}),
             'created': ('django.db.models.fields.DateTimeField', [], {'auto_now_add': 'True', 'blank': 'True'}),
-            'memory': ('json_field.fields.JSONField', [], {'default': "u'{}'", 'blank': 'True'}),
+            'memory': ('json_field.fields.JSONField', [], {'default': '{}', 'blank': 'True'}),
             'owner': ('django.db.models.fields.related.ForeignKey', [], {'to': u"orm['auth.User']"}),
             'updated': ('django.db.models.fields.DateTimeField', [], {'auto_now': 'True', 'blank': 'True'}),
             'uuid': ('api.fields.UuidField', [], {'unique': 'True', 'max_length': '32', 'primary_key': 'True'}),
-            'values': ('json_field.fields.JSONField', [], {'default': "u'{}'", 'blank': 'True'})
+            'values': ('json_field.fields.JSONField', [], {'default': '{}', 'blank': 'True'})
         },
         u'api.container': {
             'Meta': {'ordering': "[u'created']", 'object_name': 'Container'},

controller/api/views.py

@@ -396,7 +396,12 @@ def create(self, request, *args, **kwargs):
         obj = self.get_object()
         request.DATA['app'] = obj.app
         for attr in ['cpu', 'memory', 'values']:
-            data = getattr(obj, attr).copy()
+            # Guard against migrations from older apps without fixes to
+            # JSONField encoding.
+            try:
+                data = getattr(obj, attr).copy()
+            except AttributeError:
+                data = {}
             if attr in request.DATA:
                 # merge config values
                 provided = json.loads(request.DATA[attr])