If you’re using the default json-file driver, set max-file and max-size appropriately to have Docker rotate and remove old logs automatically.

Here’s how to reduce the size of your docker log drastically. Perfect for testing or a home lab where you run long lived stand alone containers and don’t need to keep a long audit trail of logging.

Check size

docker inspect --format='' $(docker ps -a -q) | sudo xargs -n 1 du -ah

Docker compose

A maximum of five log files with a max file size of 10 Mb each is set for example. As a result, the container can store up to 50 Mb worth of data. Adjust those parameters as needed.

Remember to put " " around the values:

my-app:
image: my-app:latest
logging:
    driver: "json-file"
    options:
        max-file: "5" # number of files or file count
        max-size: "10m" # file size

Configure the default logging driver

To make the Docker daemon default to a certain logging driver, set the name of that driver as the value for log-driver in the daemon.json configuration file.

You can also configure this as a default in your daemon setting. In fact, we can even use the local driver as the default logging driver, The local logging driver captures output from the container’s stdout/stderr and writes them to internal storage that is optimized for performance and disk use. set the log-driver and log-opt keys to appropriate values in the daemon.json file:

The local driver by default keeps 100MB of log messages per container and uses automatic compression to reduce the size of the disk. The 100MB default value is calculated on the basis of a 20M file size and a default count of 5 such files (to take into account log rotation). We can shrink it even further

If the daemon.json does not exist we can create it for the first time and then restart docker

sudo cat <<EOF > /etc/docker/daemon.json
{
  "log-driver": "local",
  "log-opts": {
    "max-size": "10m"
  }
}
EOF
systemctl restart docker

Logs are stored in a custom format designed for minimal overhead.