Merge branch 'develop' into babolivier/mark_unread

1 files changed, 169 insertions, 48 deletions

diff --git a/synapse/config/database.py b/synapse/config/database.py
index 118aafbd4a..1064c2697b 100644
--- a/synapse/config/database.py
+++ b/synapse/config/database.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2020 The Matrix.org Foundation C.I.C.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -12,73 +13,185 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import logging
 import os
-from textwrap import indent
 
-import yaml
+from synapse.config._base import Config, ConfigError
 
-from ._base import Config
+logger = logging.getLogger(__name__)
 
+NON_SQLITE_DATABASE_PATH_WARNING = """\
+Ignoring 'database_path' setting: not using a sqlite3 database.
+--------------------------------------------------------------------------------
+"""
 
-class DatabaseConfig(Config):
-    def read_config(self, config, **kwargs):
-        self.event_cache_size = self.parse_size(config.get("event_cache_size", "10K"))
+DEFAULT_CONFIG = """\
+## Database ##
+
+# The 'database' setting defines the database that synapse uses to store all of
+# its data.
+#
+# 'name' gives the database engine to use: either 'sqlite3' (for SQLite) or
+# 'psycopg2' (for PostgreSQL).
+#
+# 'args' gives options which are passed through to the database engine,
+# except for options starting 'cp_', which are used to configure the Twisted
+# connection pool. For a reference to valid arguments, see:
+#   * for sqlite: https://docs.python.org/3/library/sqlite3.html#sqlite3.connect
+#   * for postgres: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS
+#   * for the connection pool: https://twistedmatrix.com/documents/current/api/twisted.enterprise.adbapi.ConnectionPool.html#__init__
+#
+#
+# Example SQLite configuration:
+#
+#database:
+#  name: sqlite3
+#  args:
+#    database: /path/to/homeserver.db
+#
+#
+# Example Postgres configuration:
+#
+#database:
+#  name: psycopg2
+#  args:
+#    user: synapse
+#    password: secretpassword
+#    database: synapse
+#    host: localhost
+#    cp_min: 5
+#    cp_max: 10
+#
+# For more information on using Synapse with Postgres, see `docs/postgres.md`.
+#
+database:
+  name: sqlite3
+  args:
+    database: %(database_path)s
+"""
+
+
+class DatabaseConnectionConfig:
+    """Contains the connection config for a particular database.
 
-        self.database_config = config.get("database")
+    Args:
+        name: A label for the database, used for logging.
+        db_config: The config for a particular database, as per `database`
+            section of main config. Has three fields: `name` for database
+            module name, `args` for the args to give to the database
+            connector, and optional `data_stores` that is a list of stores to
+            provision on this database (defaulting to all).
+    """
 
-        if self.database_config is None:
-            self.database_config = {"name": "sqlite3", "args": {}}
+    def __init__(self, name: str, db_config: dict):
+        db_engine = db_config.get("name", "sqlite3")
 
-        name = self.database_config.get("name", None)
-        if name == "psycopg2":
-            pass
-        elif name == "sqlite3":
-            self.database_config.setdefault("args", {}).update(
+        if db_engine not in ("sqlite3", "psycopg2"):
+            raise ConfigError("Unsupported database type %r" % (db_engine,))
+
+        if db_engine == "sqlite3":
+            db_config.setdefault("args", {}).update(
                 {"cp_min": 1, "cp_max": 1, "check_same_thread": False}
             )
-        else:
-            raise RuntimeError("Unsupported database type '%s'" % (name,))
-
-        self.set_databasepath(config.get("database_path"))
-
-    def generate_config_section(self, data_dir_path, database_conf, **kwargs):
-        if not database_conf:
-            database_path = os.path.join(data_dir_path, "homeserver.db")
-            database_conf = (
-                """# The database engine name
-          name: "sqlite3"
-          # Arguments to pass to the engine
-          args:
-            # Path to the database
-            database: "%(database_path)s"
-            """
-                % locals()
-            )
-        else:
-            database_conf = indent(yaml.dump(database_conf), " " * 10).lstrip()
 
-        return (
-            """\
-        ## Database ##
+        data_stores = db_config.get("data_stores")
+        if data_stores is None:
+            data_stores = ["main", "state"]
+
+        self.name = name
+        self.config = db_config
+        self.data_stores = data_stores
+
+
+class DatabaseConfig(Config):
+    section = "database"
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
 
-        database:
-          %(database_conf)s
-        # Number of events to cache in memory.
+        self.databases = []
+
+    def read_config(self, config, **kwargs):
+        # We *experimentally* support specifying multiple databases via the
+        # `databases` key. This is a map from a label to database config in the
+        # same format as the `database` config option, plus an extra
+        # `data_stores` key to specify which data store goes where. For example:
         #
-        #event_cache_size: 10K
-        """
-            % locals()
-        )
+        #   databases:
+        #       master:
+        #           name: psycopg2
+        #           data_stores: ["main"]
+        #           args: {}
+        #       state:
+        #           name: psycopg2
+        #           data_stores: ["state"]
+        #           args: {}
+
+        multi_database_config = config.get("databases")
+        database_config = config.get("database")
+        database_path = config.get("database_path")
+
+        if multi_database_config and database_config:
+            raise ConfigError("Can't specify both 'database' and 'databases' in config")
+
+        if multi_database_config:
+            if database_path:
+                raise ConfigError("Can't specify 'database_path' with 'databases'")
+
+            self.databases = [
+                DatabaseConnectionConfig(name, db_conf)
+                for name, db_conf in multi_database_config.items()
+            ]
+
+        if database_config:
+            self.databases = [DatabaseConnectionConfig("master", database_config)]
+
+        if database_path:
+            if self.databases and self.databases[0].name != "sqlite3":
+                logger.warning(NON_SQLITE_DATABASE_PATH_WARNING)
+                return
+
+            database_config = {"name": "sqlite3", "args": {}}
+            self.databases = [DatabaseConnectionConfig("master", database_config)]
+            self.set_databasepath(database_path)
+
+    def generate_config_section(self, data_dir_path, **kwargs):
+        return DEFAULT_CONFIG % {
+            "database_path": os.path.join(data_dir_path, "homeserver.db")
+        }
 
     def read_arguments(self, args):
-        self.set_databasepath(args.database_path)
+        """
+        Cases for the cli input:
+          - If no databases are configured and no database_path is set, raise.
+          - No databases and only database_path available ==> sqlite3 db.
+          - If there are multiple databases and a database_path raise an error.
+          - If the database set in the config file is sqlite then
+            overwrite with the command line argument.
+        """
+
+        if args.database_path is None:
+            if not self.databases:
+                raise ConfigError("No database config provided")
+            return
+
+        if len(self.databases) == 0:
+            database_config = {"name": "sqlite3", "args": {}}
+            self.databases = [DatabaseConnectionConfig("master", database_config)]
+            self.set_databasepath(args.database_path)
+            return
+
+        if self.get_single_database().name == "sqlite3":
+            self.set_databasepath(args.database_path)
+        else:
+            logger.warning(NON_SQLITE_DATABASE_PATH_WARNING)
 
     def set_databasepath(self, database_path):
+
         if database_path != ":memory:":
             database_path = self.abspath(database_path)
-        if self.database_config.get("name", None) == "sqlite3":
-            if database_path is not None:
-                self.database_config["args"]["database"] = database_path
+
+        self.databases[0].config["args"]["database"] = database_path
 
     @staticmethod
     def add_arguments(parser):
@@ -89,3 +202,11 @@ class DatabaseConfig(Config):
             metavar="SQLITE_DATABASE_PATH",
             help="The path to a sqlite database to use.",
         )
+
+    def get_single_database(self) -> DatabaseConnectionConfig:
+        """Returns the database if there is only one, useful for e.g. tests
+        """
+        if not self.databases:
+            raise Exception("More than one database exists")
+
+        return self.databases[0]