1 files changed, 158 insertions, 0 deletions
diff --git a/src/leap/soledad/common/couch/state.py b/src/leap/soledad/common/couch/state.py
new file mode 100644
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+++ b/src/leap/soledad/common/couch/state.py
@@ -0,0 +1,158 @@
+# -*- coding: utf-8 -*-
+# state.py
+# Copyright (C) 2015,2016 LEAP
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+"""
+Server state using CouchDatabase as backend.
+"""
+import couchdb
+import re
+
+from six.moves.urllib.parse import urljoin
+
+from leap.soledad.common.log import getLogger
+from leap.soledad.common.couch import CouchDatabase
+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__)
+
+
+def is_db_name_valid(name):
+    """
+    Validate a user database using a regular expression.
+
+    :param name: database name.
+    :type name: str
+
+    :return: boolean for name vailidity
+    :rtype: bool
+    """
+    db_name_regex = "^user-[a-f0-9]+$"
+    return re.match(db_name_regex, name) is not None
+
+
+class CouchServerState(ServerState):
+
+    """
+    Inteface of the WSGI server with the CouchDB backend.
+    """
+
+    def __init__(self, couch_url, create_cmd=None,
+                 check_schema_versions=False):
+        """
+        Initialize the couch server state.
+
+        :param couch_url: The URL for the couch database.
+        :type couch_url: str
+        :param create_cmd: Command to be executed for user db creation. It will
+                           receive a properly sanitized parameter with user db
+                           name and should access CouchDB with necessary
+                           privileges, which server lacks for security reasons.
+        :type create_cmd: str
+        :param check_schema_versions: Whether to check couch schema version of
+                                      user dbs. Set to False as this is only
+                                      intended to run once during start-up.
+        :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:
+                    logger.error(
+                        "Unsupported database schema in database %s" % dbname)
+                    raise WrongCouchSchemaVersionError(dbname)
+            else:
+                result = db.view('_all_docs', limit=1)
+                if result.total_rows != 0:
+                    logger.error(
+                        "Missing couch config document in database %s"
+                        % dbname)
+                    raise MissingCouchConfigDocumentError(dbname)
+
+    def open_database(self, dbname):
+        """
+        Open a couch database.
+
+        :param dbname: The name of the database to open.
+        :type dbname: str
+
+        :return: The SoledadBackend object.
+        :rtype: SoledadBackend
+        """
+        url = urljoin(self.couch_url, dbname)
+        db = CouchDatabase.open_database(url, create=False)
+        return db
+
+    def ensure_database(self, dbname):
+        """
+        Ensure couch database exists.
+
+        :param dbname: The name of the database to ensure.
+        :type dbname: str
+
+        :raise Unauthorized: If disabled or other error was raised.
+
+        :return: The SoledadBackend object and its replica_uid.
+        :rtype: (SoledadBackend, str)
+        """
+        if not self.create_cmd:
+            raise Unauthorized()
+        else:
+            code, out = exec_validated_cmd(self.create_cmd, dbname,
+                                           validator=is_db_name_valid)
+            if code is not 0:
+                logger.error("""
+                    Error while creating database (%s) with (%s) command.
+                    Output: %s
+                    Exit code: %d
+                    """ % (dbname, self.create_cmd, out, code))
+                raise Unauthorized()
+        db = self.open_database(dbname)
+        return db, db.replica_uid
+
+    def delete_database(self, dbname):
+        """
+        Delete couch database.
+
+        :param dbname: The name of the database to delete.
+        :type dbname: str
+
+        :raise Unauthorized: Always, because Soledad server is not allowed to
+                             delete databases.
+        """
+        raise Unauthorized()