Word of the Day: container image

Word of the Day Daily updates on the latest technology terms |April 10, 2018

container image A container image is an unchangeable, static file that includes executable code so it can run an isolated process on information technology (IT) infrastructure. The image is comprised of system libraries, system tools and other platforms settings a software program needs to run on a containerization platform such as Docker or CoreOS Rkt. The image shares the OS kernel of its host machine. A container image is compiled from file system layers built onto a parent or base image. These layers encourage reuse of various components, so the user does not create everything from scratch for every project. Technically, a base image is used for a wholly new image, while a parent indicates modification of an existing image. However, in practice, the terms are used interchangeably. Types of container images A user creates a container image from scratch with the build command of a container platform, such as Docker. The container image maker can update it over time to introduce more functionality, fix bugs or otherwise change the product, and can modify the image to use it as the basis for a new container. For increased automation, the set of layers are described by the user in a Dockerfile, and these are assembled into the image. Each command in the Dockerfile creates a new layer in the image. Continuous integration tools such as Jenkins can also automate a container image build. Many software vendors create publicly available images of their products. For example, Microsoft offers a SQL Server 2017 container image that runs on Docker. Container adopters should be aware of the existence of corrupt, fake and malicious publicly available container images, sometimes disguised to resemble official vendors' images. Container images are stored in a registry that is either private or public on a repository, such as Docker Hub. The image creator pushes it to the registry, and a user pulls the image when they want to run it as a container. Features such as Docker Content Trust rely on digital signatures to help verify that images files downloaded from public repositories are original and unaltered. However, this added verification of authenticity does not prevent the creation or distribution of malware. Some images are purposefully minimal, while others have large file sizes. Generally, they are in the range of tens of megabytes. Read more... Quote of the Day "While IT operations is not responsible for creating container images, they can expect to deploy, manage, monitor and orchestrate the containers." - Alan R. Earls   Trending Terms Docker CoreOS rkt continuous integration Docker Hub app containerization kernel   Learning Center Select the best container monitoring tools for your environment Different kinds of container monitoring tools track a wide range of data that keeps applications, networks and servers running as they should. How to select, build and protect container images Ensure the appropriate container image deploys safely and repeatably to production, with strategic processes and smart tools in place. Use Azure Container Registry to manage Docker images Azure Container Registry can store Docker images locally to avoid latency. Follow these steps to get started, and to learn about integration options. Build Docker container images with AWS CodeBuild Developers can use AWS CodeBuild, an alternative to Jenkins, to automate several aspects of a software release, including building Docker images. Azure Container Instances provide an opt-out option for cluster ops Azure Container Instances deliver containers as a service for use in test and development, container pilot programs and other setups. Writing for Business If you're not _______ well-versed in microservices and containers, you're running at the back of the pack. A. already B. all ready Answer   Stay In Touch For feedback about any of our definitions or to suggest a new definition, please contact me at: mrouse@techtarget.com   Visit the Word of the Day Archives and catch up on what you've missed!   FOLLOW US About This E-Newsletter This e-newsletter is published by the TechTarget network. To unsubscribe from Whatis.com, click here. Please note, this will not affect any other subscriptions you have signed up for. TechTarget, Whatis, 275 Grove Street, Newton, MA 02466. Contact: webmaster@techtarget.com Copyright 2018 TechTarget. All rights reserved.