Understanding build configurations - Builds using BuildConfig | CI/CD | Red Hat OpenShift <strong>service</strong> on AWS

BuildConfigs

The following sections define the concept of a build, build configuration, and outline the primary build strategies available.

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BuildConfigs

A build configuration describes a single build definition and a set of triggers for when a new build is created. Build configurations are defined by a BuildConfig, which is a REST object that can be used in a POST to the API server to create a new instance.

A build configuration, or BuildConfig, is characterized by a build strategy and one or more sources. The strategy determines the process, while the sources provide its input.

Depending on how you choose to create your application using Red Hat OpenShift service on AWS, a BuildConfig is typically generated automatically for you if you use the web console or CLI, and it can be edited at any time. Understanding the parts that make up a BuildConfig and their available options can help if you choose to manually change your configuration later.

The following example BuildConfig results in a new build every time a container image tag or the source code changes:

BuildConfig object definition

kind: BuildConfig
apiVersion: build.openshift.io/v1
metadata:
  name: "ruby-sample-build" (1)
spec:
  runPolicy: "Serial" (2)
  triggers: (3)
    -
      type: "GitHub"
      github:
        secret: "secret101"
    - type: "Generic"
      generic:
        secret: "secret101"
    -
      type: "ImageChange"
  source: (4)
    git:
      uri: "https://github.com/openshift/ruby-hello-world"
  strategy: (5)
    sourceStrategy:
      from:
        kind: "ImageStreamTag"
        name: "ruby-20-centos7:latest"
  output: (6)
    to:
      kind: "ImageStreamTag"
      name: "origin-ruby-sample:latest"
  postCommit: (7)
      script: "bundle exec rake test"

1	This specification creates a new `BuildConfig` named `ruby-sample-build`.
2	The `runPolicy` field controls whether builds created from this build configuration can be run simultaneously. The default value is `Serial`, which means new builds run sequentially, not simultaneously.
3	You can specify a list of triggers, which cause a new build to be created.
4	The `source` section defines the source of the build. The source type determines the primary source of input, and can be either `Git`, to point to a code repository location, `Dockerfile`, to build from an inline Dockerfile, or `Binary`, to accept binary payloads. It is possible to have multiple sources at once. See the documentation for each source type for details.
5	The `strategy` section describes the build strategy used to execute the build. You can specify a `Source` , `Docker`, or `Custom` strategy here. This example uses the `ruby-20-centos7` container image that Source-to-image (S2I) uses for the application build.
6	After the container image is successfully built, it is pushed into the repository described in the `output` section.
7	The `postCommit` section defines an optional build hook.