Add info about logging (#1239)

* Add info about logging

* Add SMS wordlist and change MonoLog

.wordlist.txt

@@ -1291,6 +1291,7 @@ slowlog
 sm
 smartbar
 SMTP
+SMS
 snakeCase
 SnippetFileInterface
 SomeCoreClassTest

guides/hosting/configurations/framework/monolog.md

@@ -0,0 +1,48 @@
+---
+nav:
+  title: Monolog
+  position: 20
+
+---
+
+# Monolog
+
+## Overview
+
+Monolog is a logging library for PHP. It is used by Shopware to log errors and debug information. The log files are located in the `var/log` directory of your Shopware installation.
+
+## Configuration
+
+Configuration of Monolog is done in the `config/packages/prod/monolog.yaml` file. The following example shows the default configuration:
+
+<<< @/docs/snippets/config/monolog.yaml
+
+
+## Log levels
+
+Monolog supports the following log levels:
+
+- `DEBUG`: Detailed debug information.
+- `INFO`: Interesting events. Examples: User logs in, SQL logs.
+- `NOTICE`: Normal but significant events.
+- `WARNING`: Exceptional occurrences that are not errors. Examples: Use of deprecated APIs, poor use of an API, undesirable things that are not necessarily wrong.
+- `ERROR`: Runtime errors that do not require immediate action but should typically be logged and monitored.
+- `CRITICAL`: Critical conditions. Example: Application component unavailable, unexpected exception.
+- `ALERT`: Action must be taken immediately. Example: Entire website down, database unavailable, etc. This should trigger the SMS alerts and wake you up.
+- `EMERGENCY`: Emergency: system is unusable.
+
+
+## Log sent e-mails and other flow events
+
+To monitor all sent e-mails and other flow events set the `business_event_handler_buffer` to `info` level:
+
+```yaml
+monolog:
+  handlers:
+    business_event_handler_buffer:
+      level: info
+```
+
+::: info
+Be aware that this will cost you some performance.
+:::

snippets/config/monolog.yaml

@@ -0,0 +1,18 @@
+monolog:
+  handlers:
+    main:
+      type: fingers_crossed
+      action_level: error
+      handler: nested
+      excluded_http_codes: [404, 405]
+      buffer_size: 30 # How many messages should be saved? Prevent memory leaks
+    business_event_handler_buffer:
+      level: error
+    nested:
+      type: rotating_file
+      path: "%kernel.logs_dir%/%kernel.environment%.log"
+      level: error
+    console:
+      type: console
+      process_psr_3_messages: false
+      channels: ["!event", "!doctrine"]