From 50dda813e24db454b376866906e9281b7dafcb3a Mon Sep 17 00:00:00 2001
From: Florian Klink <flokli@flokli.de>
Date: Fri, 17 May 2019 00:10:34 +0200
Subject: [PATCH] nixos/mysql: use systemd.tmpfiles to setup dataDir and pidDir

We need to keep using `RuntimeDirectory=mysqld`, which translates to
`/run/mysqld`, as this is used for the location of the file socket, that
could differ with what is configured via `cfg.pidDir`.
---
 nixos/modules/services/databases/mysql.nix | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/nixos/modules/services/databases/mysql.nix b/nixos/modules/services/databases/mysql.nix
index 7e3c230fff7..daa3b6c34dd 100644
--- a/nixos/modules/services/databases/mysql.nix
+++ b/nixos/modules/services/databases/mysql.nix
@@ -296,6 +296,11 @@ in
       ${cfg.extraOptions}
     '';
 
+    systemd.tmpfiles.rules = [
+      "d '${cfg.dataDir}' 0700 ${cfg.user} mysql -"
+      "d '${cfg.pidDir}' 0755 ${cfg.user} mysql -"
+    ];
+
     systemd.services.mysql = let
       hasNotify = (cfg.package == pkgs.mariadb);
     in {
@@ -316,19 +321,17 @@ in
         preStart =
           ''
             if ! test -e ${cfg.dataDir}/mysql; then
-                mkdir -m 0700 -p ${cfg.dataDir}
-                chown -R ${cfg.user} ${cfg.dataDir}
                 ${mysql}/bin/mysql_install_db --defaults-file=/etc/my.cnf ${installOptions}
                 touch /tmp/mysql_init
             fi
 
-            mkdir -m 0755 -p ${cfg.pidDir}
-            chown -R ${cfg.user} ${cfg.pidDir}
           '';
 
         serviceConfig = {
           Type = if hasNotify then "notify" else "simple";
+          # /run/mysqld needs to be created in addition to pidDir, as they could point to different locations
           RuntimeDirectory = "mysqld";
+          RuntimeDirectoryMode = "0755";
           # The last two environment variables are used for starting Galera clusters
           ExecStart = "${mysql}/bin/mysqld --defaults-file=/etc/my.cnf ${mysqldOptions} $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION";
         };