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File audit device

The file audit device writes audit logs to a file. This is a very simple audit device: it appends logs to a file.

The device does not currently assist with any log rotation. There are very stable and feature-filled log rotation tools already, so we recommend using existing tools.

Sending a SIGHUP to the OpenBao process will cause file audit devices to close and re-open their underlying file, which can assist with log rotation needs.

warning

The File audit device is sensitive as it can write to arbitrary files on the instance. Be cautious when granting operators the ability to create this device via the API when unsafe_allow_api_audit_creation=true is set.

Consider using declarative audit configuration instead.

Examples​

Enable at the default path:

$ bao audit enable file file_path=/var/log/openbao_audit.log

Enable at a different path. It is possible to enable multiple copies of an audit device:

$ bao audit enable -path="openbao_audit_1" file file_path=/home/user/openbao_audit.log

Enable logs on stdout. This is useful when running in a container:

$ bao audit enable file file_path=stdout

Configuration​

Note the difference between audit enable command options and the file backend configuration options. Use bao audit enable -help to see the command options.

The file audit device supports the common configuration options documented on the main Audit Devices page, and these device-specific options:

  • file_path (string: <required>) - The path to where the audit log will be written. If a file already exists at the given path, the audit backend will append to it. There are some special keywords:

    • stdout writes the audit log to standard output

    • discard discards output, instead of writing it to a device (useful in testing scenarios)

  • mode (string: "0600") - A string containing an octal number representing the bit pattern for the file mode, similar to chmod. Set to "0000" to prevent OpenBao from modifying the file mode.

    warning

    Note: Starting with OpenBao v2.4.0, any executable bits set in mode are zeroed automatically, for security purposes. For example, mode = 777 will convert to mode = 666. Furthermore, mode values that are irregular are rejected with an error.

Log file rotation​

To properly rotate OpenBao File Audit Device log files on BSD, Darwin, or Linux-based OpenBao servers, it is important that you configure your log rotation software to send the bao process a signal hang up / SIGHUP after each rotation of the log file.