How do I enable 'debug' logging of the Docker daemon?

Article ID: KB000316

To enable debug logging of the Docker daemon use the following the steps:

  1. Edit /etc/docker/daemon.json, setting"debug": true. If this file does not exist, it should look like this when complete:

        "debug": true
  2. Send a SIGHUP signal to the Docker daemon, triggering it to reload its configuration without restarting the process.

    sudo kill -SIGHUP $(pidof dockerd)
  3. (optional) To check that the configuration has been applied, check docker info. If debug is enabled, the output will show Debug Mode (server): true.

    docker info | grep -i debug.*server

To disable debug logging, perform both steps again, setting "debug": false.

This process works on all supported versions of Linux. Refer to the Compatibility Matrix for a list of specific versions.

The product documentation for this procedure can be found in the Docker docs.