Documentation Grafana Agent Flow mode Reference Configuration blocks logging

logging block

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

Example

river Copy

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

Arguments

The following arguments are supported:

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:

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

Log receivers

The write_to argument allows Grafana Agent Flow 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 ship log entries directly to Loki, or a loki.relabel component to add a certain label first.

Log location

Grafana Agent Flow writes all logs to stderr.

When running Grafana Agent Flow as a systemd service, view logs written to stderr through journald.

When running Grafana Agent Flow as a container, view logs written to stderr through docker logs or kubectl logs, depending on whether Docker or Kubernetes was used for deploying Grafana Agent Flow.

When running Grafana Agent Flow as a Windows service, logs are instead written as event logs. You can view the logs through Event Viewer.

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