From b475eb435619a97ee183fd716720e682433e07ae Mon Sep 17 00:00:00 2001
From: Raul Marin <git@rmr.ninja>
Date: Mon, 28 Oct 2019 14:08:07 +0100
Subject: [PATCH] Federated Server List

---
 scripts-available/CDB_FederatedServer.sql   | 70 +++++++++++++++++++++
 scripts-enabled/400-CDB_FederatedServer.sql |  1 +
 test/CDB_FederatedServer.sql                | 43 +++++++++++++
 test/CDB_FederatedServer_expect             |  0
 4 files changed, 114 insertions(+)
 create mode 100644 scripts-available/CDB_FederatedServer.sql
 create mode 120000 scripts-enabled/400-CDB_FederatedServer.sql
 create mode 100644 test/CDB_FederatedServer.sql
 create mode 100644 test/CDB_FederatedServer_expect

diff --git a/scripts-available/CDB_FederatedServer.sql b/scripts-available/CDB_FederatedServer.sql
new file mode 100644
index 0000000..46af6d8
--- /dev/null
+++ b/scripts-available/CDB_FederatedServer.sql
@@ -0,0 +1,70 @@
+
+-- This function is just a placement to store and use the pattern for
+-- foreign server names
+CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Name_Pattern()
+RETURNS TEXT
+AS $$
+    SELECT 'cdb_fs_';
+$$
+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)
+RETURNS NAME
+AS $$
+DECLARE
+    object_name text := format('%s%s', @extschema@.__CDB_FS_Name_Pattern(), fdw_input_name);
+BEGIN
+  -- We discard anything that would be truncated
+  IF (char_length(object_name) < 64) THEN
+    RETURN object_name::name;
+  ELSE
+    RAISE EXCEPTION 'Object name is too long to be used as identifier';
+  END IF;
+END
+$$
+LANGUAGE PLPGSQL 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 '%')
+RETURNS TABLE (
+    name        text,
+    driver      text,
+    host        text,
+    port        text,
+    dbname      text,
+    readmode    text,
+    username    text
+)
+AS $$
+DECLARE
+    server_name text := concat(@extschema@.__CDB_FS_Name_Pattern() || fdw_pattern);
+BEGIN
+    RETURN QUERY SELECT 
+        -- Name as shown to the user
+        right(s.srvname, char_length(s.srvname::TEXT) - char_length(@extschema@.__CDB_FS_Name_Pattern()))::TEXT AS "Name",
+
+        -- Which driver are we using (postgres_fdw, odbc_fdw...)
+        f.fdwname::text AS "Driver",
+
+        -- Read 
+        (SELECT option_value FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'host') AS "Host",
+        (SELECT option_value FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'port') AS "Port",
+        (SELECT option_value FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'dbname') AS "DBName",
+        CASE WHEN (SELECT NOT option_value::boolean FROM pg_options_to_table(s.srvoptions) WHERE option_name LIKE 'updatable') THEN 'read-only' ELSE 'read-write' END AS "ReadMode",
+
+        -- Read username from user mappings
+        (SELECT option_value FROM pg_options_to_table(u.umoptions) WHERE option_name LIKE 'user') AS "Username"
+    FROM pg_foreign_server s
+    JOIN pg_foreign_data_wrapper f ON f.oid=s.srvfdw
+    LEFT JOIN pg_user_mappings u
+    ON u.srvid = s.oid
+    WHERE s.srvname ILIKE server_name
+    ORDER BY 1;
+END
+$$
+LANGUAGE PLPGSQL IMMUTABLE PARALLEL SAFE;
diff --git a/scripts-enabled/400-CDB_FederatedServer.sql b/scripts-enabled/400-CDB_FederatedServer.sql
new file mode 120000
index 0000000..6a3df9a
--- /dev/null
+++ b/scripts-enabled/400-CDB_FederatedServer.sql
@@ -0,0 +1 @@
+../scripts-available/CDB_FederatedServer.sql
\ No newline at end of file
diff --git a/test/CDB_FederatedServer.sql b/test/CDB_FederatedServer.sql
new file mode 100644
index 0000000..dd25170
--- /dev/null
+++ b/test/CDB_FederatedServer.sql
@@ -0,0 +1,43 @@
+-- Setup
+\set QUIET on
+SET client_min_messages TO error;
+SET SESSION AUTHORIZATION postgres;
+\set QUIET off
+
+-- Register a new server
+SELECT '1.1', cartodb.CDB_Federated_Server_List_Servers();
+-- SELECT '1.2', cartodb.CDB_Federated_Server_Register_PG();
+-- SELECT '1.3', cartodb.CDB_Federated_Server_List_Servers();
+-- 
+-- Register a second server
+-- SELECT '2.1', cartodb.CDB_Federated_Server_Register_PG();
+-- SELECT '2.2', cartodb.CDB_PG_Federated_Server_List_Servers();
+-- 
+-- Re-register the second server
+-- SELECT '3.1', cartodb.CDB_Federated_Server_Register_PG();
+-- SELECT '3.2', cartodb.CDB_PG_Federated_Server_List_Servers();
+-- 
+-- Unregister #1
+-- SELECT '4.1', cartodb.CDB_PG_Federated_Server_Unregister();
+-- SELECT '4.2', cartodb.CDB_PG_Federated_Server_List_Servers();
+-- 
+-- Unregister #2
+-- SELECT '5.1', cartodb.CDB_PG_Federated_Server_Unregister();
+-- SELECT '5.2', cartodb.CDB_PG_Federated_Server_List_Servers();
+
+-- Should show the appropiate output (database, read-write, user, pass)
+
+-- Test multiple user mappings
+
+-- Should work ok with special characters in the name
+
+-- Should throw with invalid or NULL config
+
+-- -- List works with multiple and single server
+
+-- Cleanup
+\set QUIET on
+
+\set QUIET off
+
+
diff --git a/test/CDB_FederatedServer_expect b/test/CDB_FederatedServer_expect
new file mode 100644
index 0000000..e69de29