moby--moby/contrib/man/md/docker-build.md

% DOCKER(1) Docker User Manuals % William Henry % APRIL 2014

NAME

docker-build - Build a container image from a Dockerfile source at PATH

SYNOPSIS

docker build [--no-cache[=false] [-q|--quiet[=false] [-rm] [-t|--tag=tag] PATH | URL | -

DESCRIPTION

This will read the Dockerfile from the directory specified in PATH. It also sends any other files and directories found in the current directory to the Docker daemon. The contents of this directory would be used by ADD commands found within the Dockerfile.

Warning, this will send a lot of data to the Docker daemon depending on the contents of the current directory. The build is run by the Docker daemon, not by the CLI, so the whole context must be transferred to the daemon. The Docker CLI reports "Uploading context" when the context is sent to the daemon.

When a single Dockerfile is given as the URL, then no context is set. When a Git repository is set as the URL, the repository is used as context.

OPTIONS

-q, --quiet=true|false When set to true, suppress verbose build output. Default is false.

--rm=true|false When true, remove intermediate containers that are created during the build process. The default is true.

-t, --tag=tag Tag to be applied to the resulting image on successful completion of the build.

--no-cache=true|false When set to true, do not use a cache when building the image. The default is false.

EXAMPLES

Building an image using a Dockefile located inside the current directory

Docker images can be built using the build command and a Dockerfile:

docker build .

During the build process Docker creates intermediate images. In order to keep them, you must explicitly set --rm=false.

docker build --rm=false .

A good practice is to make a sub-directory with a related name and create the Dockerfile in that directory. For example, a directory called mongo may contain a Dockerfile to create a Docker MongoDB image. Likewise, another directory called httpd may be used to store Dockerfiles for Apache web server images.

It is also a good practice to add the files required for the image to the sub-directory. These files will then be specified with the ADD instruction in the Dockerfile. Note: If you include a tar file (a good practice!), then Docker will automatically extract the contents of the tar file specified within the ADD instruction into the specified target.

Building an image using a URL

This will clone the specified Github repository from the URL and use it as context. The Dockerfile at the root of the repository is used as Dockerfile. This only works if the Github repository is a dedicated repository.

docker build github.com/scollier/Fedora-Dockerfiles/tree/master/apache

Note: You can set an arbitrary Git repository via the git:// schema.

HISTORY

March 2014, Originally compiled by William Henry (whenry at redhat dot com) based on docker.io source material and internal work.