From e4d877059c7f8bc2a11324e52fa254e4b14070af Mon Sep 17 00:00:00 2001
From: John Hampton <john.hampton@stanfordalumni.org>
Date: Fri, 12 Apr 2024 08:14:38 -0700
Subject: [PATCH 1/2] fix(postgres): fix pg_isready issue with empty
 listen_addresses

This commit resolves the issue where `pg_isready` would fail when
`socketDir` is set and `listen_addresses` is empty. `pg_isready` is now
modified to leverage `socketDir` when it is available.
---
 nix/postgres/default.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nix/postgres/default.nix b/nix/postgres/default.nix
index 8611e03f..f9d114e7 100644
--- a/nix/postgres/default.nix
+++ b/nix/postgres/default.nix
@@ -323,7 +323,7 @@ in
                   '';
                 };
                 pg_isreadyArgs = [
-                  "-h ${config.listen_addresses}"
+                  (if config.socketDir != "" then "-h $(readlink -f \"${config.socketDir}\")" else "-h ${config.listen_addresses}")
                   "-p ${toString config.port}"
                   "-d template1"
                 ] ++ (lib.optional (config.superuser != null) "-U ${config.superuser}");

From 0922b13db8eff1ab8819e3202d2045a32ec719bf Mon Sep 17 00:00:00 2001
From: John Hampton <john.hampton@stanfordalumni.org>
Date: Sat, 13 Apr 2024 17:56:50 -0700
Subject: [PATCH 2/2] test(postgres): set socketDir with empty listen_addresses

Test a postgres service with socketDir set and empty listen_addresses.
---
 nix/postgres/postgres_test.nix | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/nix/postgres/postgres_test.nix b/nix/postgres/postgres_test.nix
index d2b0580e..1adf9789 100644
--- a/nix/postgres/postgres_test.nix
+++ b/nix/postgres/postgres_test.nix
@@ -16,8 +16,19 @@
       }
     ];
   };
+  services.postgres."pg3" = {
+    enable = true;
+    socketDir = "./test/new/socket/path2";
+    listen_addresses = "";
+    initialDatabases = [
+      {
+        name = "test-db";
+      }
+    ];
+  };
   # avoid both the processes trying to create `data` directory at the same time
   settings.processes."pg2-init".depends_on."pg1-init".condition = "process_completed_successfully";
+  settings.processes."pg3-init".depends_on."pg2-init".condition = "process_completed_successfully";
   settings.processes.test =
     let
       cfg = config.services.postgres."pg1";
@@ -37,12 +48,16 @@
 
           # schemas test
           echo "SELECT * from users where user_name = 'test_user';" | psql -h 127.0.0.1 -p 5433 -d sample-db | grep -q test_user
+         
+          # listen_addresses test
+          echo "SELECT 1 FROM pg_database where datname = 'test-db';" | psql -h "$(readlink -f ${config.services.postgres.pg3.socketDir})" -d postgres | grep -q 1
         '';
         name = "postgres-test";
       };
       depends_on = {
         "pg1".condition = "process_healthy";
         "pg2".condition = "process_healthy";
+        "pg3".condition = "process_healthy";
       };
     };
 }