Code review (round 1)

server/server.yml

@@ -233,13 +233,31 @@
 # stripe-secret-key:
 # stripe-webhook-key:
 
-# Log level, can be "trace", "debug", "info", "warn" or "error"
-# This option can be hot-reloaded by calling "kill -HUP $pid" or "systemctl reload ntfy".
+# Logging options
 #
-# FIXME
+# By default, ntfy logs to the console (stderr), with a "info" log level, and in a human-readable text format.
+# ntfy supports five different log levels, can also write to a file, log as JSON, and even supports granular
+# log level overrides for easier debugging. Some options (log-level and log-level-overrides) can be hot reloaded
+# by calling "kill -HUP $pid" or "systemctl reload ntfy".
 #
-# Be aware that "debug" (and particularly "trace"") can be VERY CHATTY. Only turn them on for
-# debugging purposes, or your disk will fill up quickly.
+# - log-format defines the output format, can be "text" (default) or "json"
+# - log-file is a filename to write logs to. If this is not set, ntfy logs to stderr.
+# - log-level defines the default log level, can be one of "trace", "debug", "info" (default), "warn" or "error".
+#   Be aware that "debug" (and particularly "trace") can be VERY CHATTY. Only turn them on briefly for debugging purposes.
+# - log-level-overrides lets you override the log level if certain fields match. This is incredibly powerful
+#   for debugging certain parts of the system (e.g. only the account management, or only a certain visitor).
+#   This is an array of strings in the format "field=value -> level", e.g. "tag=manager -> trace".
+#   Warning: Using log-level-overrides has a performance penalty. Only use it for temporary debugging.
+#
+# Example (good for production):
+#   log-level: info
+#   log-format: json
+#   log-file: /var/log/ntfy.log
+#
+# Example level overrides (for debugging, only use temporarily):
+#   log-level-overrides:
+#      - "tag=manager -> trace"
+#      - "visitor_ip=1.2.3.4 -> debug"
 #
 # log-level: info
 # log-level-overrides: