feat[logging]: flexible logging support

config.example.toml

@@ -10,3 +10,26 @@ ssh_key = "/home/user/id_rsa"
 # Use this fetch config instead of ssh_key to clone over HTTP(S):
 # user = "gitea-user"
 # token = "XXXXX"
+
+[logging]
+level = "INFO"
+
+# Human-friendly logs in stdout.
+[[logging.outputs]]
+type = "console"
+format = "plain"
+stream = "stdout"
+
+# Docker-friendly structured logs in stderr.
+[[logging.outputs]]
+type = "console"
+format = "json"
+stream = "stderr"
+
+# Rotating file logs with selectable format.
+[[logging.outputs]]
+type = "file"
+path = "/var/log/gitea-mirror/gitea-mirror.log"
+format = "json"
+max_size = 10485760
+backup_count = 5