[feature] check for user dbs couch schema versions

2 files changed, 45 insertions, 2 deletions

diff --git a/common/src/leap/soledad/common/couch/state.py b/common/src/leap/soledad/common/couch/state.py
index e3cd1a24..1d045a9d 100644
--- a/common/src/leap/soledad/common/couch/state.py
+++ b/common/src/leap/soledad/common/couch/state.py
@@ -17,6 +17,7 @@
 """
 Server state using CouchDatabase as backend.
 """
+import couchdb
 import re
 import time
 from urlparse import urljoin
@@ -25,9 +26,14 @@ from hashlib import sha512
 from leap.soledad.common.log import getLogger
 from leap.soledad.common.couch import CouchDatabase
 from leap.soledad.common.couch import couch_server
+from leap.soledad.common.couch import CONFIG_DOC_ID
+from leap.soledad.common.couch import SCHEMA_VERSION
+from leap.soledad.common.couch import SCHEMA_VERSION_KEY
 from leap.soledad.common.command import exec_validated_cmd
 from leap.soledad.common.l2db.remote.server_state import ServerState
 from leap.soledad.common.l2db.errors import Unauthorized
+from leap.soledad.common.errors import WrongCouchSchemaVersionError
+from leap.soledad.common.errors import MissingCouchConfigDocumentError
 
 
 logger = getLogger(__name__)
@@ -59,15 +65,41 @@ class CouchServerState(ServerState):
     TOKENS_TYPE_DEF = "Token"
     TOKENS_USER_ID_KEY = "user_id"
 
-    def __init__(self, couch_url, create_cmd=None):
+    def __init__(self, couch_url, create_cmd=None,
+                 check_schema_versions=True):
         """
         Initialize the couch server state.
 
         :param couch_url: The URL for the couch database.
         :type couch_url: str
+        :param check_schema_versions: Whether to check couch schema version of
+                                      user dbs.
+        :type check_schema_versions: bool
         """
         self.couch_url = couch_url
         self.create_cmd = create_cmd
+        if check_schema_versions:
+            self._check_schema_versions()
+
+    def _check_schema_versions(self):
+        """
+        Check that all user databases use the correct couch schema.
+        """
+        server = couchdb.client.Server(self.couch_url)
+        for dbname in server:
+            if not dbname.startswith('user-'):
+                continue
+            db = server[dbname]
+
+            # if there are documents, ensure that a config doc exists
+            config_doc = db.get(CONFIG_DOC_ID)
+            if config_doc:
+                if config_doc[SCHEMA_VERSION_KEY] != SCHEMA_VERSION:
+                    raise WrongCouchSchemaVersionError(dbname)
+            else:
+                result = db.view('_all_docs', limit=1)
+                if result.total_rows != 0:
+                    raise MissingCouchConfigDocumentError(dbname)
 
     def open_database(self, dbname):
         """
diff --git a/common/src/leap/soledad/common/errors.py b/common/src/leap/soledad/common/errors.py
index dec871c9..d543a3de 100644
--- a/common/src/leap/soledad/common/errors.py
+++ b/common/src/leap/soledad/common/errors.py
@@ -77,7 +77,6 @@ http_errors.ERROR_STATUSES = set(
 
 
 class InvalidURLError(Exception):
-
     """
     Exception raised when Soledad encounters a malformed URL.
     """
@@ -90,3 +89,15 @@ class BackendNotReadyError(SoledadError):
     """
     wire_description = "backend not ready"
     status = 500
+
+
+class WrongCouchSchemaVersionError(SoledadError):
+    """
+    Raised in case there is a user database with wrong couch schema version.
+    """
+
+
+class MissingCouchConfigDocumentError(SoledadError):
+    """
+    Raised if a database has documents but lacks the couch config document.
+    """