Merge branch 'uid-migration' into 'master'

Add migration which converts database and LDAP UIDs to lowercase

ARSnova Backend now converts all user IDs for database user accounts to
lowercase. This migration converts existing accounts for compatibility.
Documents mapped to LDAP UIDs are also reassigned to lowercase UIDs
since most LDAP configurations use case-insesitive comparison for UIDs.

This change was done to prevent duplicate account creation.

See merge request !3

migrations.py

 import couchconnection
 import json
+import re
 
 (db, conn) = couchconnection.arsnova_connection("/etc/arsnova/arsnova.properties")
 
@@ -195,6 +196,85 @@ def migrate(migration):
         print bump(current_version)
 
     if current_version == 8:
+        print "Migrating DB and LDAP user IDs to lowercase..."
+        conn.request("GET", db_url + "/_design/user/_view/all")
+        res = conn.getresponse()
+        doc = json.loads(res.read())
+        affected_users = {}
+        unaffected_users = []
+        bulk_docs = []
+
+        # Look for user documents where user ID is not in lowercase
+        #   1) Delete document if account has not been activated
+        #   2) Lock account if a lowercase version already exists
+        #   3) Convert user ID to lowercase if only one captitalization exists
+        for user_doc in doc["rows"]:
+            if user_doc["key"] != user_doc["key"].lower():
+                # create a list of user documents since there might be multiple
+                # items for different captitalizations
+                affected_users.setdefault(user_doc["key"].lower(), []).append(user_doc["value"])
+            else:
+                unaffected_users.append(user_doc["key"])
+        for uid, users in affected_users.iteritems():
+            migration_targets = []
+            for user in users:
+                if "activationKey" in user:
+                    print "User %s has not been activated. Deleting document %s..." % (user["username"], user["_id"])
+                    conn.delete(db_url + "/" + user["_id"])
+                elif uid in unaffected_users:
+                    print "Migration target exists. Locking duplicate user %s (document %s)..." % (user["username"], user["_id"])
+                    user["locked"] = True
+                    bulk_docs.append(user)
+                else:
+                    migration_targets.append(user)
+            if len(migration_targets) > 1:
+                print "Cannot migrate some users automatically. Conflicting duplicate users found:"
+                for user in migration_targets:
+                    print "Locking user %s (document %s)..." % (user["username"], user["_id"])
+                    user["locked"] = True
+                    bulk_docs.append(user)
+            elif migration_targets:
+                print "Migrating user %s (document %s)..." % (user["username"], user["_id"])
+                user["username"] = uid
+                bulk_docs.append(user)
+
+        # Look for data where assigned user's ID is not in lowercase
+        #   1) Migrate if user ID was affected by previous migration step
+        #   2) Exclude Facebook and Google account IDs
+        #   3) Exclude guest account IDs
+        #   4) Migrate all remaining IDs (LDAP)
+        def reassign_data(type, user_prop):
+            print "Reassigning %s data to migrated users..." % type
+            migration_view = "{ \"map\": \"function(doc) { function check(doc, type, uid) { return doc.type === type && uid !== uid.toLowerCase() && uid.indexOf('Guest') !== 0; } if (check(doc, '%s', doc.%s)) { emit(doc._id, doc); }}\" }" % (type, user_prop)
+            res = conn.temp_view(db_url, migration_view)
+            doc = json.loads(res.read())
+            print "Documents: %d" % len(doc["rows"])
+            for affected_doc in doc["rows"]:
+                val = affected_doc["value"]
+                print affected_doc["id"], val[user_prop]
+                # exclude Facebook and Google accounts from migration (might be
+                # redundant)
+                if (not re.match("https?:", val[user_prop]) and not "@" in val[user_prop]) or val[user_prop].lower() in affected_users:
+                    val[user_prop] = val[user_prop].lower()
+                    bulk_docs.append(val)
+                else:
+                    print "Skipped %s (Facebook/Google account)" % val[user_prop]
+
+        reassign_data("session", "creator")
+        reassign_data("interposed_question", "creator")
+        reassign_data("skill_question_answer", "user")
+        reassign_data("logged_in", "user")
+        reassign_data("motdlist", "username")
+
+        # bulk update users and assignments
+        res = conn.json_post(bulk_url, json.dumps({"docs": bulk_docs}))
+        if res:
+            res.read()
+            # bump database version
+            current_version = 9
+            print bump(current_version)
+
+    if current_version == 9:
         # Next migration goes here
         pass