kolla/docs/image-building.md

Image building

The tools/build-docker-image script in this repository is responsible for building docker images. It is symlinked as ./build inside each Docker image directory.

When creating new image directories, you can run the tools/update-build-links scripts to install the build symlink (this script will install the symlink anywhere it find a file named Dockerfile).

Workflow

In general, you will build images like this:

$ cd docker/keystone
$ ./build

By default, the above command would build kollaglue/centos-rdo-keystone:CID, where CID is the current short commit ID. That is, given:

$ git rev-parse HEAD
76a16029006a2f5d3b79f1198d81acb6653110e9

The above command would generate kollaglue/centos-rdo-keystone:76a1602. This tagging is meant to prevent developers from stepping on each other or on release images during the development process.

To push the image after building, add --push:

$ ./build --push

To use these images, you must specify the tag in your docker run commands:

$ docker run kollaglue/centos-rdo-keystone:76a1602

Building releases

To build into the latest tag, add --release:

$ ./build --release

Or to build and push:

$ ./build --push --release

Build all images at once

The build-all-docker-images script in the tools directory is a wrapper for the build-docker-image that builds all images, as the name suggests, in the correct order. It responds to the same options as build-docker-image with the additional --from and --to options that allows building only images that have changed between the specified git revisions.

For example, to build all images contained in docker directory and push new release:

$ tools/build-all-docker-images --release --push

To build only images modified in test-branch along with their children:

$ tools/build-all-docker-images --from master --to test-branch

Configuration

The build-docker-image script will look for a file named .buildconf in the image directory and in the top level of the repository. You can use this to set defaults, such as:

NAMESPACE=larsks
PREFIX=fedora-rdo-

This setting would cause images to be tagged into the larsks/ namespace and use Fedora as base image instead of the default CentOS.