feat: add read replica support

.env.example

@@ -54,6 +54,13 @@ POSTGRES_PASSWORD=
 RAILS_ENV=development
 # Changes the Postgres query timeout limit. The default is 14 seconds. Modify only when required.
 # POSTGRES_STATEMENT_TIMEOUT=14s
+
+# read replica configuration for production
+# POSTGRES_HOST_RR=postgres_rr
+# create a new user with readonly permissions
+# POSTGRES_USERNAME_RR=postgres_readonly
+# POSTGRES_PASSWORD_RR=
+
 RAILS_MAX_THREADS=5
 
 # The email from which all outgoing emails are sent

app/models/application_record.rb

@@ -2,6 +2,8 @@ class ApplicationRecord < ActiveRecord::Base
   include Events::Types
   self.abstract_class = true
 
+  connects_to database: { writing: :primary, reading: :primary_replica }
+
   before_validation :validates_column_content_length
 
   # the models that exposed in email templates through liquid

config/database.yml

@@ -22,7 +22,15 @@ test:
   password: "<%= ENV.fetch('POSTGRES_PASSWORD', '') %>"
 
 production:
-  <<: *default
-  database: "<%= ENV.fetch('POSTGRES_DATABASE', 'chatwoot_production') %>"
-  username: "<%= ENV.fetch('POSTGRES_USERNAME', 'chatwoot_prod') %>"
-  password: "<%= ENV.fetch('POSTGRES_PASSWORD', 'chatwoot_prod') %>"
+  primary:
+    <<: *default
+    database: "<%= ENV.fetch('POSTGRES_DATABASE', 'chatwoot_production') %>"
+    username: "<%= ENV.fetch('POSTGRES_USERNAME', 'chatwoot_prod') %>"
+    password: "<%= ENV.fetch('POSTGRES_PASSWORD', 'chatwoot_prod') %>"
+  primary_replica:
+    <<: *default
+    host: "<%= ENV.fetch('POSTGRES_HOST_RR', 'localhost') %>"
+    database: "<%= ENV.fetch('POSTGRES_DATABASE', 'chatwoot_production') %>"
+    username: "<%= ENV.fetch('POSTGRES_USERNAME_RR', 'chatwoot_prod_readonly') %>"
+    password: "<%= ENV.fetch('POSTGRES_PASSWORD_RR', 'chatwoot_prod') %>"
+    replica: true