With many years of experience in the IT industry, Rafael Benevides helps developers and companies all over the world to be more effective in software development. Rafael considers himself a problem solver who has a big love for sharing. He is a member of Apache DeltaSpike PMC - a Duke’s Choice Award winner project, and a speaker in conferences like JavaOne, Devoxx, TDC, DevNexus, and many others.
"Linux containers (sometimes managed using the docker command) keep applications and their runtime components together by combining lightweight application isolation with an image-based deployment method". ( https://developers.redhat.com/topics/kubernetes ) Red Hat Developer program brings a very useful cheat sheet to those who need to create or work with containers, images, volumes and networks. When you download the sheet, you will find: An illustrated cheat sheet with commands related to the management of containers, Dockerfile instructions to craft your own image, and...
In a world where agility matters, the pursuit to reduce wasted time in environment configurations is apparent in many technologies. Some techniques, such as Virtual Machines, that enable distribution of pre-configured images have existed for decades, while others like Linux containers are more recent. Even platforms like Java allow developers to package all dependencies, resources and configuration files in single JAR (Java Archive) file. What started initially as way to have executable Java classes in Java SE (Standard Edition), has...
A recent blog post, 10 things to avoid in docker containers , describes ten scenarios you should avoid when dealing with docker containers. However, recommendation # 3 - Don’t create large images and the sentence "Don’t install unnecessary packages or run “updates” ( yum update) that download files to a new image layer" has generated quite a few questions. Some of you are wondering how a simple yum update can create a large image. In an attempt to clarify the...
So you finally surrendered to containers and discovered that they solve a lot of problems and have a lot of advantages: First: Containers are immutable - The OS, library versions, configurations, folders, and application are all wrapped inside the container. You guarantee that the same image that was tested in QA will reach the production environment with the same behaviour. Second: Containers are lightweight - The memory footprint of a container is small. Instead of hundreds or thousands of MBs...