Logger: File

text-format (string)

output text format, please refer to the default text format to see all available text directives, use this parameter if you want a specific format.
jinja-format (string)

jinja template, please refer Jinja templating to see all available directives
postrotate-command (string)

Specifies a command or script to run after each file rotation.
postrotate-delete-success (boolean)

Deletes the rotated file if the post-rotate script completes successfully.s
chan-buffer-size (integer)

Specifies the maximum number of packets that can be buffered before discard additional packets. Set to zero to use the default global value.
overwrite-dns-port-pcap (bool)

tThis option is used only with the pcap output mode. It replaces the destination port with 53, ensuring no distinction between DoT, DoH, and DoQ.

Default configuration:

logfile:
  file-path: null
  max-size: 100
  max-files: 10
  max-batch-size: 65536
  flush-interval: 1
  compress: false
  mode: text
  text-format: ""
  jinja-format: ""
  postrotate-command: null
  postrotate-delete-success: false
  chan-buffer-size: 0
  overwrite-dns-port-pcap: false

Full configuration examples

Log Compression

When enabled, gzip log compression runs asynchronously for each completed log file. During the rotation process, files are initially renamed with a tocompress- prefix, e.g., tocompress-dnstap-1730099215373568947.log, indicating they’re pending compression. Once compression finishes, the file is renamed to dnstap-1730099215373568947.log.gz, replacing the tocompress- prefix and adding the .gz suffix to mark completion.

Only one compression task runs at a time to optimize system performance, ensuring sequential compression of files.

To enable log compression, set compress to true in your configuration file:

logfile:
  compress: true

Postrotate command

The postrotate-command option allows you to specify a script to execute after each file rotation. During the post-rotate process, files are temporarily renamed with a toprocess- prefix, for example, toprocess-dnstap-1730099215373568947.log. The script receives three arguments: - Arg. 1: The full path to the log file - Arg. 2: The directory path containing the log file - Arg. 3: The filename without the toprocess- prefix

Example Configuration

To specify a post-rotate command, add the following configuration:

logfile:
  postrotate-command: "/home/dnscollector/postrotate.sh"

Example Script

Here’s a sample script that moves the log file to a date-specific backup folder:

#!/bin/bash

DNSCOLLECTOR=/var/dnscollector/
BACKUP_FOLDER=$DNSCOLLECTOR/$(date +%Y-%m-%d)
mkdir -p $BACKUP_FOLDER

# Move the log file to the backup folder, excluding the 'toprocess-' prefix from the filename
mv $1 $BACKUP_FOLDER/$3

Note: If compression is enabled, the postrotate-command will run only after compression completes.

Save to DNStap files

You can configure the collector to save traffic in DNStap format. Only available with logger file.