From 274eab725f9d68532ebdb21ec9a970df76b7ac09 Mon Sep 17 00:00:00 2001
From: toast-ts <96593068+toast-ts@users.noreply.github.com>
Date: Sat, 27 Jan 2024 19:21:22 +1100
Subject: [PATCH] Setup a master/slave replication in Postgres

---
 docker-compose.yml                            |  4 +++-
 .../configs/postgres-hba.conf                 | 11 +++++++++
 postgres-replica-stuff/configs/postgres.conf  | 23 +++++++++++++++++++
 postgres-replica-stuff/docker-compose.yml     | 15 ++++++++++++
 .../postgres-setup-replica.sql                |  8 +++++++
 tsconfig.json                                 |  8 +++----
 6 files changed, 64 insertions(+), 5 deletions(-)
 create mode 100644 postgres-replica-stuff/configs/postgres-hba.conf
 create mode 100644 postgres-replica-stuff/configs/postgres.conf
 create mode 100644 postgres-replica-stuff/docker-compose.yml
 create mode 100644 postgres-replica-stuff/postgres-setup-replica.sql

diff --git a/docker-compose.yml b/docker-compose.yml
index 662da97..7a61ddc 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -6,13 +6,15 @@ services:
     ports:
       - 6379:6379/tcp
   db:
-    container_name: postgres-db
+    container_name: postgres-master
     image: postgres:16.1-alpine3.19
     restart: unless-stopped
     ports:
       - 5432:5432/tcp
     volumes:
       - /var/lib/docker/volumes/daggerbot-db:/var/lib/postgresql/data:rw
+      - ./postgres-replica-stuff/configs/postgres-hba.conf:/var/lib/postgresql/data/pg_hba.conf:rw
+      - ./postgres-replica-stuff/configs/postgres.conf:/var/lib/postgresql/data/postgresql.conf:rw
     environment:
       POSTGRES_USER: ${POSTGRES_USER}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
diff --git a/postgres-replica-stuff/configs/postgres-hba.conf b/postgres-replica-stuff/configs/postgres-hba.conf
new file mode 100644
index 0000000..82089e7
--- /dev/null
+++ b/postgres-replica-stuff/configs/postgres-hba.conf
@@ -0,0 +1,11 @@
+# TYPE  DATABASE        USER            ADDRESS                 METHOD
+# "local" is for Unix domain socket connections only
+local   all             all                                     trust
+# IPv4 local connections:
+host    all             all             127.0.0.1/32            trust
+# Allow replication connections from localhost, by a user with the
+# replication privilege.
+local   replication     all                                     trust
+host    replication     replicator      0.0.0.0/0               trust
+
+host all all all scram-sha-256
diff --git a/postgres-replica-stuff/configs/postgres.conf b/postgres-replica-stuff/configs/postgres.conf
new file mode 100644
index 0000000..192ca67
--- /dev/null
+++ b/postgres-replica-stuff/configs/postgres.conf
@@ -0,0 +1,23 @@
+listen_addresses = '*'
+
+max_connections = 128
+shared_buffers = 256MB
+effective_cache_size = 4GB
+maintenance_work_mem = 128MB
+work_mem = 8MB
+checkpoint_completion_target = 0.9
+wal_buffers = 16MB
+default_statistics_target = 100
+random_page_cost = 2.5
+effective_io_concurrency = 1
+min_wal_size = 64MB
+max_wal_size = 2GB
+max_worker_processes = 6
+max_parallel_workers_per_gather = 4
+
+# Standby replication setup
+wal_level = replica
+max_wal_senders = 12
+max_replication_slots = 12
+hot_standby = on
+hot_standby_feedback = on
diff --git a/postgres-replica-stuff/docker-compose.yml b/postgres-replica-stuff/docker-compose.yml
new file mode 100644
index 0000000..54f593f
--- /dev/null
+++ b/postgres-replica-stuff/docker-compose.yml
@@ -0,0 +1,15 @@
+# This is for the Slave node, Master node is in the root directory of the same file.
+services:
+  db-slave:
+    container_name: postgres-slave
+    image: postgres:16.1-alpine3.19
+    restart: unless-stopped
+    ports:
+      - 5433:5432/tcp
+    volumes:
+      - /var/lib/docker/volumes/daggerbot-db-slave:/var/lib/postgresql/data:rw
+      - ./configs/postgres-hba.conf:/var/lib/postgresql/data/pg_hba.conf:rw
+      - ./configs/postgres.conf:/var/lib/postgresql/data/postgresql.conf:rw
+    environment:
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
+      POSTGRES_DB: ${POSTGRES_DB}
diff --git a/postgres-replica-stuff/postgres-setup-replica.sql b/postgres-replica-stuff/postgres-setup-replica.sql
new file mode 100644
index 0000000..6521c02
--- /dev/null
+++ b/postgres-replica-stuff/postgres-setup-replica.sql
@@ -0,0 +1,8 @@
+-- This is for the slave.
+CREATE USER replicator WITH REPLICATION ENCRYPTED PASSWORD '<password_here>';
+
+-- This is for the master.
+SELECT * FROM pg_create_physical_replication_slot('replication_slot_slave');
+SELECT * FROM pg_replication_slots;
+
+-- https://medium.com/swlh/postgresql-replication-with-docker-c6a904becf77
diff --git a/tsconfig.json b/tsconfig.json
index 9db2728..bdd2702 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -12,11 +12,11 @@
     "target": "ES2022",
     "module": "ESNext",
     "baseUrl": "./",
-    "rootDir": "src/",
-    "outDir": "dist/",
+    "rootDir": "src",
+    "outDir": "dist",
     "moduleResolution": "bundler",
     "typeRoots": [ "./src/interfaces.d.ts" ]
   },
-  "include": [ "src/" ],
-  "exclude": [ ".yarn/cache", ".yarn/unplugged", ".git", "src/errorBlocklist.json", "src/config.json", "src/DB-Beta.config.json" ]
+  "include": [ "src" ],
+  "exclude": [ ".yarn/cache", ".yarn/unplugged", ".git", "src/*.json", "postgres-replica-stuff" ]
 }