Docker: how to debug containers and the network between services?

Effective debugging and troubleshooting of issues in Docker containers and distributed networks between services require a comprehensive approach consisting of metrics collection, logging, and performance analysis. Optimizing infrastructure without prior measurements and precise data turns into a blind guessing game that wastes the team's working time.

For deep analysis of container performance, it is first necessary to configure proper logging using standard Docker mechanisms, such as the docker logs command with the follow flag to track events in real-time. In addition, it is useful to use external log aggregation systems like the ELK stack or Prometheus with Grafana to collect CPU, RAM, and disk space usage metrics.

Regarding the debugging of the network between various services within the Docker environment, it is critically important to check network configurations using the docker network inspect commands and use temporary containers to test host and port availability. For example, you can run a lightweight container with curl or netcat utilities to test network connections, resolve hostname issues in user-defined bridge networks, and ensure that ports are correctly forwarded and available for interaction.