How to Limit and Manage Docker Container Logs

If you’re using Docker in production or development, container logs can silently consume a significant amount of disk space over time. By default, Docker uses the json-file log driver, which stores logs in large, ever-growing files unless configured otherwise.

Here’s a simple guide to limit Docker logs and prevent disk space exhaustion.

Step 1: Configure Log Rotation Globally

Edit or create the Docker daemon configuration file:

sudo nano /etc/docker/daemon.json

Add the following content:

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  }
}

This sets a 10MB max size per log file and keeps only 3 rotated files per container (i.e., ~30MB max per container).

Then, restart Docker:

sudo systemctl restart docker

Step 2: Apply Log Limits to Specific Containers (Optional)

When running containers manually, you can override log settings:

docker run \
  --log-driver=json-file \
  --log-opt max-size=10m \
  --log-opt max-file=3 \
  your-image

Step 3: Locate and Clear Container Logs (if needed)

To find a container’s log file:

docker inspect <container-id> --format=''

Clear it manually if it gets too large:

sudo truncate -s 0 /path/to/container-id-json.log

To truncate all container logs:

sudo find /var/lib/docker/containers/ -name "*-json.log" -exec truncate -s 0 {} \;

Bonus: List All Large Log Files

sudo find /var/lib/docker/containers/ -name "*.log" -exec du -h {} + | sort -hr | head -20

That’s it! Now your Docker containers will no longer silently consume your disk space. Log management is crucial for performance, monitoring, and maintenance — and it only takes a few minutes to set up properly.

References

• Configure logging drivers