ShellHacks

Adding labels to Docker images is a good practice as this custom metadata permits to organize images by environments, record build information and is very helpful in automation. This guide will show you 2 ways of how to add custom metadata to Docker images.

Docker image is built up from a series of layers that represent instructions in the image’s Dockerfile. Sometimes it may be necessary to show an image layers, their sizes and the instructions they have been created of. In this note i will show how to list all layers a Docker image is composed of, show […]

The good practice is to tag Docker images with useful tags, e.g. version, intended destination (prod or staging), stability or any other information that is useful when deploying the application in different environments. In this note i will show how to tag Docker images with one or multiple tags during a build. Also i will […]

A minimal Docker image based on Alpine Linux has only 5 MB in size, but a lot of tools common for Linux distributions (e.g. curl) are not installed by default. In this short note i will show how to install curl in Alpine container from the command line. I will also show how to build […]

A docker run command is one of the basic commands in a Docker universe as it is used to start containers from Docker images. In this short note i will show how to start a Docker container in a foreground, in a background or with an interactive shell session of bash or sh from the […]