[#64] make max_connections to postgresql configurable

CHANGELOG.md

@@ -6,6 +6,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- [#64] make max_connections to postgresql configurable
 
 ## [v14.18-2] - 2025-08-25
 ### Fixed

dogu.json

@@ -118,6 +118,12 @@
         "Type": "BINARY_MEASUREMENT"
       }
     },
+    {
+      "Name": "database_config/max_connections",
+      "Description": "Maximum amount of allowed database connections. Allowing to many connections can increase hardware requirements.",
+      "Optional": true,
+      "Default": "100"
+    },
     {
       "Name": "logging/root",
       "Description": "Set the root log level to one of ERROR, WARN, INFO, DEBUG.",

resources/startup.sh

@@ -131,6 +131,12 @@ function setDoguLogLevel() {
   echo "log_min_messages = ${POSTGRESQL_LOGLEVEL}" >>/var/lib/postgresql/postgresql.conf
 }
 
+function setMaxConnections() {
+  # replace default max connection count with configured max connection count
+  cons=$(doguctl config 'database_config/max_connections')
+  sed -i "/max_connections/c\max_connections = ${cons}" /var/lib/postgresql/postgresql.conf
+}
+
 function runMain() {
   # check whether post-upgrade script is still running
   while [[ "$(doguctl config "local_state" -d "empty")" == "upgrading" ]]; do
@@ -147,6 +153,7 @@ function runMain() {
 
   write_pg_hba_conf
   setDoguLogLevel
+  setMaxConnections
 
   # set stage for health check
   doguctl state ready