Fixing wal archiving permission issues

Author: dutow

deploy/docker-compose.yml

@@ -3,6 +3,7 @@ version: "3.9"
 services:
   db:
     image: postgres:18
+    entrypoint: ["/usr/local/bin/custom-entrypoint.sh"]
     environment:
       POSTGRES_USER: ${POSTGRES_USER:-postgres}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-postgres}
@@ -13,6 +14,7 @@ services:
       - pgwal:/var/lib/postgresql/wal-archive
       - pgbackups:/backups
       - ./postgres/postgresql.conf:/etc/postgresql/postgresql.conf:ro # copy from postgresql.conf.example
+      - ./postgres/entrypoint.sh:/usr/local/bin/custom-entrypoint.sh:ro
     command:
       [
         "postgres",

deploy/postgres/entrypoint.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Ensure WAL archive directory exists and is owned by postgres so archive_command can write.
+mkdir -p /var/lib/postgresql/wal-archive
+chown -R postgres:postgres /var/lib/postgresql/wal-archive
+
+exec /usr/local/bin/docker-entrypoint.sh "$@"

deploy/postgres/postgresql.conf.example

@@ -1,12 +1,16 @@
+listen_addresses = '*'
+
+# Memory and planner
 shared_buffers = 4GB
 effective_cache_size = 12GB
 work_mem = 32MB
 maintenance_work_mem = 1GB
 
+# WAL and archiving
 wal_level = replica
 wal_compression = on
 archive_mode = on
 archive_timeout = 60s
-archive_command = 'test ! -f /var/lib/postgresql/wal-archive/%f && cp %p /var/lib/postgresql/wal-archive/%f' # keep && unescaped so the shell runs both commands
+archive_command = 'test ! -f /var/lib/postgresql/wal-archive/%f && cp %p /var/lib/postgresql/wal-archive/%f'
 max_wal_size = 8GB
 min_wal_size = 2GB