Book Image

Learning Docker - Second Edition

By : Vinod Singh, Pethuru Raj, Jeeva S. Chelladhurai
Book Image

Learning Docker - Second Edition

By: Vinod Singh, Pethuru Raj, Jeeva S. Chelladhurai

Overview of this book

Docker is an open source containerization engine that offers a simple and faster way for developing and running software. Docker containers wrap software in a complete filesystem that contains everything it needs to run, enabling any application to be run anywhere – this flexibily and portabily means that you can run apps in the cloud, on virtual machines, or on dedicated servers. This book will give you a tour of the new features of Docker and help you get started with Docker by building and deploying a simple application. It will walk you through the commands required to manage Docker images and containers. You’ll be shown how to download new images, run containers, list the containers running on the Docker host, and kill them. You’ll learn how to leverage Docker’s volumes feature to share data between the Docker host and its containers – this data management feature is also useful for persistent data. This book also covers how to orchestrate containers using Docker compose, debug containers, and secure containers using the AppArmor and SELinux security modules.
Table of Contents (13 chapters)

The docker stats command

The docker stats command provides you with the capability to view the memory, CPU, and the network usage of a container from a Docker host machine, as illustrated here:

$ sudo docker stats a245253db38b
CONTAINER CPU % MEM USAGE/LIMIT MEM % NET I/O
a245253db38b 0.02% 16.37 MiB/992.5 MiB 1.65%
3.818 KiB/2.43 KiB

You can run the stats command to also view the usage for multiple containers:

$ sudo docker stats a245253db38b f71b26cee2f1   

Docker provides access to container statistics read only parameters. This streamlines the CPU, memory, network IO, and block IO of containers. This helps you choose the resource limits and also in profiling. The Docker stats utility provides you with these resource usage details only for running containers.