Adding option initialDumps to Postgres (#67)

---------

Co-authored-by: Shivaraj B H <sbh69840@gmail.com>

nix/postgres/default.nix

@@ -230,6 +230,16 @@ in
       '';
     };
 
+    initialDumps = lib.mkOption {
+      type = types.listOf types.path;
+      default = [ ];
+      description = ''List of SQL dumps to run during the database initialization.
+      These dumps are loaded after `initalScript` and `initialDatabases`.'';
+      example = lib.literalExpression ''
+        [ ./foo.sql ./bar.sql ]
+      '';
+    };
+
     initialScript = lib.mkOption {
       type = types.submodule ({ config, ... }: {
         options = {

nix/postgres/postgres_test.nix

@@ -4,6 +4,7 @@
     listen_addresses = "127.0.0.1";
     initialScript.before = "CREATE USER bar;";
     initialScript.after = "CREATE DATABASE foo OWNER bar;";
+    initialDumps = [ ./test.sql ];
   };
   settings.processes.test =
     let
@@ -21,6 +22,9 @@
 
           # initialScript.after test
           echo "SELECT 1 FROM pg_database WHERE datname = 'foo';" | psql -h 127.0.0.1 | grep -q 1
+
+          #intialDumps test
+          echo "SELECT * from users where user_name = 'test_user';" | psql -h 127.0.0.1 -d postgres | grep -q test_user
         '';
         name = "postgres-test";
       };

nix/postgres/setup-script.nix

@@ -43,6 +43,15 @@ let
     else
       lib.optionalString config.createDatabase ''
         echo "CREATE DATABASE ''${USER:-$(id -nu)};" | psql -d postgres '';
+
+  runInitialDumps =
+    let
+      scriptCmd = dump: ''
+        psql -d postgres < ${dump}
+      '';
+    in
+    builtins.concatStringsSep "\n" (map scriptCmd config.initialDumps);
+
   runInitialScript =
     let
       scriptCmd = sqlScript: ''
@@ -112,6 +121,7 @@ in
       ${runInitialScript.before}
       ${setupInitialDatabases}
       ${runInitialScript.after}
+      ${runInitialDumps}
       pg_ctl -D "$PGDATA" -m fast -w stop
       remove_tmp_pg_init_sock_dir "$PGHOST"
     else

nix/postgres/test.sql

@@ -0,0 +1,4 @@
+CREATE TABLE users (id INT PRIMARY KEY, user_name VARCHAR(25));
+
+INSERT INTO users values (1, 'test_user');
+