WIP: Add CDB_Federated_Server_Unregister

scripts-available/CDB_FederatedServer.sql

@@ -10,7 +10,7 @@ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
 
 
 -- Produce a valid DB name for objects created for the user FDW's
-CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Object_Name(fdw_input_name NAME)
+CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Generate_Object_Name(fdw_input_name NAME)
 RETURNS NAME
 AS $$
 DECLARE
@@ -26,11 +26,19 @@ END
 $$
 LANGUAGE PLPGSQL IMMUTABLE PARALLEL SAFE;
 
+CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Extract_Public_Name(fdw_stored_name NAME)
+RETURNS TEXT
+AS $$
+    SELECT right(fdw_stored_name,
+            char_length(fdw_stored_name::TEXT) -  char_length(@extschema@.__CDB_FS_Name_Pattern()))::TEXT;
+$$
+LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
 
 
 -- List registered servers
--- TODO: Decide whether we want to show extra config (extensions, fetch_size, use_remote_estimate)s 
-CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_List_Servers(fdw_pattern TEXT DEFAULT '%')
+-- TODO: Decide whether we want to show extra config (extensions, fetch_size, use_remote_estimate)
+-- TODO: Handle multiple user mappings in the same server
+CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_List_Servers(server TEXT DEFAULT '%')
 RETURNS TABLE (
     name        text,
     driver      text,
@@ -42,22 +50,22 @@ RETURNS TABLE (
 )
 AS $$
 DECLARE
-    server_name text := concat(@extschema@.__CDB_FS_Name_Pattern() || fdw_pattern);
+    server_name text := concat(@extschema@.__CDB_FS_Name_Pattern(), server);
 BEGIN
     RETURN QUERY SELECT 
         -- Name as shown to the user
-        right(s.srvname, char_length(s.srvname::TEXT) - char_length(@extschema@.__CDB_FS_Name_Pattern()))::TEXT AS "Name",
+        @extschema@.__CDB_FS_Extract_Public_Name(s.srvname) AS "Name",
 
         -- Which driver are we using (postgres_fdw, odbc_fdw...)
         f.fdwname::text AS "Driver",
 
-        -- Read 
+        -- Read options from pg_foreign_server
         (SELECT option_value FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'host') AS "Host",
         (SELECT option_value FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'port') AS "Port",
         (SELECT option_value FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'dbname') AS "DBName",
         CASE WHEN (SELECT NOT option_value::boolean FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'updatable') THEN 'read-only' ELSE 'read-write' END AS "ReadMode",
 
-        -- Read username from user mappings
+        -- Read username from pg_user_mappings
         (SELECT option_value FROM pg_options_to_table(u.umoptions) WHERE option_name LIKE 'user') AS "Username"
     FROM pg_foreign_server s
     JOIN pg_foreign_data_wrapper f ON f.oid=s.srvfdw
@@ -68,3 +76,66 @@ BEGIN
 END
 $$
 LANGUAGE PLPGSQL IMMUTABLE PARALLEL SAFE;
+
+-- Take a config jsonb and transform it to an input suitable for
+-- _CDB_SetUp_User_PG_FDW_Server
+CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_credentials_to_user_mapping(input_config JSONB)
+RETURNS jsonb
+AS $$
+DECLARE
+    user_mapping jsonb := json_build_object(
+        'user_mapping',
+        jsonb_build_object('user', input_config->'credentials'->'username',
+                           'password', input_config->'credentials'->'password')
+        );
+BEGIN
+    RETURN (input_config - 'credentials')::jsonb || user_mapping;
+END
+$$
+LANGUAGE PLPGSQL IMMUTABLE PARALLEL SAFE;
+
+-- Take a config jsonb as input and return it augmented with default
+-- options
+CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_add_default_options(input_config jsonb)
+RETURNS jsonb
+AS $$
+DECLARE
+    default_options jsonb := '{
+        "extensions": "postgis",
+        "updatable": "false",
+        "use_remote_estimate": "true",
+        "fetch_size": "1000"
+    }';
+    server_config jsonb;
+BEGIN
+    server_config := default_options || to_jsonb(input_config->'server');
+    RETURN jsonb_set(input_config, '{server}'::text[], server_config);
+END
+$$
+LANGUAGE PLPGSQL IMMUTABLE PARALLEL SAFE;
+
+
+CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_Register_PG(server TEXT, config JSONB)
+RETURNS void
+AS $$
+DECLARE
+    -- TODO: Check and handle existing servers (if needed)
+    final_name text := @extschema@.__CDB_FS_Generate_Object_Name(server);
+    final_config jsonb := @extschema@.__CDB_FS_credentials_to_user_mapping(@extschema@.__CDB_FS_add_default_options(config));
+BEGIN
+    PERFORM @extschema@._CDB_SetUp_User_PG_FDW_Server(final_name, final_config::json);
+END
+$$
+LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
+
+CREATE OR REPLACE FUNCTION cartodb.CDB_Federated_Server_Unregister(server TEXT)
+RETURNS void
+AS $$
+DECLARE
+    final_name text := cartodb.__CDB_FS_Generate_Object_Name(server);
+BEGIN
+    -- TODO: Check if the server exists to show a nice error instead of the automatic one (which uses the implementation name)
+    EXECUTE 'DROP SERVER ' || quote_ident(final_name) || ' CASCADE';
+END
+$$
+LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;