Add CDB_ForeignTable functions

scripts-available/CDB_ForeignTable.sql

@@ -0,0 +1,108 @@
+---------------------------
+-- FDW MANAGEMENT FUNCTIONS
+--
+-- All the FDW settings are read from the `cdb_conf.fdws` entry json file.
+---------------------------
+
+CREATE OR REPLACE FUNCTION cartodb._CDB_Create_FDW(name text, config json)
+RETURNS void
+AS $$
+DECLARE
+  row record;
+  option record;
+  org_role text;
+BEGIN
+  IF NOT EXISTS ( SELECT * FROM pg_extension WHERE extname = 'postgres_fdw') 
+    THEN
+    CREATE EXTENSION postgres_fdw;
+  END IF;
+  -- This function is idempotent
+  -- Create FDW first if it does not exist
+  IF NOT EXISTS ( SELECT * FROM pg_foreign_server WHERE srvname = name)
+    THEN
+    EXECUTE FORMAT('CREATE SERVER %I FOREIGN DATA WRAPPER postgres_fdw ',
+      name);
+  END IF;
+
+  -- Set FDW settings
+  FOR row IN SELECT p.key, p.value from lateral json_each_text(config->'server') p
+    LOOP
+      IF NOT EXISTS (WITH a AS (select split_part(unnest(srvoptions), '=', 1) as options from pg_foreign_server where srvname=name) SELECT * from a where options = row.key)
+        THEN
+        EXECUTE FORMAT('ALTER SERVER %I OPTIONS (ADD %I %L)', name, row.key, row.value);
+      ELSE
+        EXECUTE FORMAT('ALTER SERVER %I OPTIONS (SET %I %L)', name, row.key, row.value);
+      END IF;
+    END LOOP;
+
+    -- Create user mappings
+    FOR row IN SELECT p.key, p.value from lateral json_each(config->'users') p
+      LOOP 
+        -- Check if entry on pg_user_mappings exists
+
+        IF NOT EXISTS ( SELECT * FROM pg_user_mappings WHERE srvname = name AND usename = row.key )
+          THEN
+          EXECUTE FORMAT ('CREATE USER MAPPING FOR %I SERVER %I', row.key, name);
+        END IF;
+
+    -- Update user mapping settings
+    FOR option IN SELECT o.key, o.value from lateral json_each_text(row.value) o
+      LOOP
+        IF NOT EXISTS (WITH a AS (select split_part(unnest(umoptions), '=', 1) as options from pg_user_mappings WHERE srvname = name AND usename = row.key) SELECT * from a where options = option.key)
+          THEN
+          EXECUTE FORMAT('ALTER USER MAPPING FOR %I SERVER %I OPTIONS (ADD %I %L)', row.key, name, option.key, option.value);
+        ELSE
+          EXECUTE FORMAT('ALTER USER MAPPING FOR %I SERVER %I OPTIONS (SET %I %L)', row.key, name, option.key, option.value);
+        END IF;
+      END LOOP;
+    END LOOP;
+
+    -- Create schema if it does not exist.
+    IF NOT EXISTS ( SELECT * from pg_namespace WHERE nspname=name)
+      THEN
+      EXECUTE FORMAT ('CREATE SCHEMA %I', name);
+    END IF;
+
+    -- Give the organization role usage permisions over the schema
+    SELECT cartodb.CDB_Organization_Member_Group_Role_Member_Name() INTO org_role;
+    EXECUTE FORMAT ('GRANT USAGE ON SCHEMA %I TO %I', name, org_role);
+
+    -- Bring here the remote cdb_tablemetadata
+    IF NOT EXISTS ( SELECT * FROM PG_CLASS WHERE relnamespace = (SELECT oid FROM pg_namespace WHERE nspname='do') and relname='cdb_tablemetadata') 
+      THEN
+      EXECUTE FORMAT ('IMPORT FOREIGN SCHEMA cartodb LIMIT TO (cdb_tablemetadata) FROM SERVER %I INTO %I;', name, name, name);
+    END IF;
+    EXECUTE FORMAT ('GRANT SELECT ON %I.cdb_tablemetadata TO %I', name, org_role);
+
+END
+$$
+LANGUAGE PLPGSQL;
+
+CREATE OR REPLACE FUNCTION cartodb._CDB_Create_FDWS()
+RETURNS VOID AS 
+$$
+DECLARE
+row record;
+BEGIN
+  FOR row IN SELECT p.key, p.value from lateral json_each(cartodb.CDB_Conf_GetConf('fdws')) p
+    LOOP
+      EXECUTE 'SELECT cartodb._CDB_Create_FDW($1, $2)' USING row.key, row.value;
+    END LOOP;
+  END
+  $$
+  LANGUAGE PLPGSQL;
+
+CREATE OR REPLACE FUNCTION cartodb.CDB_Add_Remote_Table(source text, table_name text)
+RETURNS void AS
+$$
+BEGIN
+PERFORM cartodb._CDB_Create_FDW(source);
+EXECUTE FORMAT ('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I) FROM SERVER %I INTO %I;', source, table_name, source, source);
+--- Grant SELECT to publicuser
+EXECUTE FORMAT ('GRANT SELECT ON %I.%I TO publicuser;', source, table_name);
+
+END
+$$
+LANGUAGE plpgsql
+security definer;
+

scripts-enabled/250-CDB_ForeignTable.sql

@@ -0,0 +1 @@
+../scripts-available/CDB_ForeignTable.sql