Documentation Grafana Cloud Instrument and send data Grafana Alloy Reference Configuration blocks logging

logging

logging is an optional configuration block used to customize how Alloy produces log messages. logging is specified without a label and can only be provided once per configuration file.

Usage

alloy Copy

logging {

}

Arguments

You can use the following arguments with logging:

Log level

The following strings are recognized as valid log levels:

• "error": Only write logs at the error level.
• "warn": Only write logs at the warn level or above.
• "info": Only write logs at info level or above.
• "debug": Write all logs, including debug level logs.

Log format

The following strings are recognized as valid log line formats:

• "json": Write logs as JSON objects.
• "logfmt": Write logs as logfmt lines.

Log receivers

The write_to argument allows Alloy to tee its log entries to one or more loki.* component log receivers in addition to the default location. This, for example can be the export of a loki.write component to send log entries directly to Loki, or a loki.relabel component to add a certain label first.

Log location

Alloy writes all logs to stderr.

When you run Alloy as a systemd service, you can view logs written to stderr through journald.

When you run Alloy as a container, you can view logs written to stderr through docker logs or kubectl logs, depending on whether Docker or Kubernetes was used for deploying Alloy.

When you run Alloy as a Windows service, logs are written as event logs. You can view the logs through Event Viewer.

In other cases, redirect stderr of the Alloy process to a file for logs to persist on disk.

Example

alloy Copy

logging {
  level  = "info"
  format = "logfmt"
}