From 18d5c1d168ada2dbc179b9009780dfcc4ee38d2b Mon Sep 17 00:00:00 2001
From: Shivaraj B H <sbh69840@gmail.com>
Date: Tue, 26 Mar 2024 18:44:11 +0530
Subject: [PATCH] fix(postgres): empty `socketDir` by default (#160)

resolves #139

> empty `unix_socket_directories` means not listening on any Unix-domain sockets, in which case only TCP/IP sockets can be used to connect to the server.

see: https://www.postgresql.org/docs/current/runtime-config-connection.html#GUC-UNIX-SOCKET-DIRECTORIES

* use TCP/IP by default for health check
---
 doc/postgresql.md             |  3 +++
 nix/postgres/default.nix      | 18 +++++++++++++-----
 nix/postgres/setup-script.nix | 19 +++++++++++++------
 3 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/doc/postgresql.md b/doc/postgresql.md
index 7629f8c..67aefdd 100644
--- a/doc/postgresql.md
+++ b/doc/postgresql.md
@@ -20,6 +20,9 @@
 {#socket-path}
 ### Unix-domain socket path is too long
 
+> [!warning]
+> Only relevant if `socketDir` is set. If not, postgres uses TCP/IP by default.
+
 We already talk about this in the [data directory guide](datadir.md#socket-path). In case of postgres, you can set `socketDir` while keeping the `dataDir` unchanged.
 
 >[!note]
diff --git a/nix/postgres/default.nix b/nix/postgres/default.nix
index 1f5dbec..8611e03 100644
--- a/nix/postgres/default.nix
+++ b/nix/postgres/default.nix
@@ -52,8 +52,12 @@ in
 
     socketDir = lib.mkOption {
       type = lib.types.str;
-      default = config.dataDir;
+      default = "";
       description = "The DB socket directory";
+      defaultText = ''
+        An empty value specifies not listening on any Unix-domain sockets, in which case only TCP/IP sockets can be used to connect to the server.
+        See: https://www.postgresql.org/docs/current/runtime-config-connection.html#GUC-UNIX-SOCKET-DIRECTORIES
+      '';
     };
 
     # Based on: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING-URIS
@@ -128,7 +132,7 @@ in
     listen_addresses = lib.mkOption {
       type = lib.types.str;
       description = "Listen address";
-      default = "";
+      default = "127.0.0.1";
       example = "127.0.0.1";
     };
 
@@ -309,13 +313,17 @@ in
                   text = ''
                     set -euo pipefail
                     PGDATA=$(readlink -f "${config.dataDir}")
-                    PGSOCKETDIR=$(readlink -f "${config.socketDir}")
                     export PGDATA
-                    postgres -k "$PGSOCKETDIR"
+                    ${ if config.socketDir != "" then ''
+                      PGSOCKETDIR=$(readlink -f "${config.socketDir}")
+                      postgres -k "$PGSOCKETDIR"
+                    '' else ''
+                      postgres
+                    ''}
                   '';
                 };
                 pg_isreadyArgs = [
-                  "-h $(readlink -f \"${config.socketDir}\")"
+                  "-h ${config.listen_addresses}"
                   "-p ${toString config.port}"
                   "-d template1"
                 ] ++ (lib.optional (config.superuser != null) "-U ${config.superuser}");
diff --git a/nix/postgres/setup-script.nix b/nix/postgres/setup-script.nix
index 59c7a1a..69dccb7 100644
--- a/nix/postgres/setup-script.nix
+++ b/nix/postgres/setup-script.nix
@@ -97,17 +97,24 @@ in
     # Setup config
     echo "Setting up postgresql.conf"
     cp ${configFile} "$PGDATA/postgresql.conf"
-    # Create socketDir if it doesn't exist
-    if [ ! -d "${config.socketDir}" ]; then
-      echo "Creating socket directory"
-      mkdir -p "${config.socketDir}"
-    fi
+    # Create socketDir if it doesn't exist and it is not empty
+    ${lib.optionalString (config.socketDir != "") ''
+      if [ ! -d "${config.socketDir}" ]; then
+        echo "Creating socket directory"
+        mkdir -p "${config.socketDir}"
+      fi
+    ''}
 
     if [[ "$POSTGRES_RUN_INITIAL_SCRIPT" = "true" ]]; then
       echo
       echo "PostgreSQL is setting up the initial database."
       echo
-      PGHOST=$(mktemp -d "$(readlink -f "${config.socketDir}")/pg-init-XXXXXX")
+      ${ if config.socketDir != "" then ''
+        PGHOST=$(mktemp -d "$(readlink -f "${config.socketDir}")/pg-init-XXXXXX")
+      '' else ''
+        PGHOST=$(mktemp -d /tmp/pg-init-XXXXXX)
+      ''
+      }
       export PGHOST
 
       function remove_tmp_pg_init_sock_dir() {