Build Strategy

Build Strategy

Build Strategy is used to control the build process. There are two types of strategies, ClusterBuildStrategy and BuildStrategy. Both strategies define a group of steps necessary to control the application build process.

ClusterBuildStrategy is cluster-wide, while BuildStrategy is namespaced.

There are 4 built-in ClusterBuildStrategy in OpenFunction, you can find more details in the following sections.

openfunction

The openfunction ClusterBuildStrategy uses Buildpacks to build function images which is the default build strategy.

The following are the parameters of the openfunction ClusterBuildStrategy:

Name	Type	Describe
RUN_IMAGE	string	Reference to a run image to use
CACHE_IMAGE	string	Cache Image is a way to preserve cache layers across different builds, which can improve build performance when building functions or applications with lots of dependencies like Java functions.
BASH_IMAGE	string	The bash image that the strategy used.
ENV_VARS	string	Environment variables to set during build-time. The formate is `key1=value1,key2=value2`.

Users can set these parameters like this:

apiVersion: core.openfunction.io/v1beta2
kind: Function
metadata:
  name: logs-async-handler
spec:
  build:
    shipwright:
      params:
        RUN_IMAGE: ""
        ENV_VARS: ""

buildah

The buildah ClusterBuildStrategy uses buildah to build application images.

To use buildah ClusterBuildStrategy, you can define a Function like this:

apiVersion: core.openfunction.io/v1beta2
kind: Function
metadata:
  name: sample-go-app
  namespace: default
spec:
  build:
    builder: openfunction/buildah:v1.23.1
    dockerfile: Dockerfile
    shipwright:
      strategy:
        kind: ClusterBuildStrategy
        name: buildah

The following are the parameters of the buildah ClusterBuildStrategy:

Name	Type	Describe	Default
registry-search	string	The registries for searching short name images such as `golang:latest`, separated by commas.	docker.io,quay.io
registry-insecure	string	The fully-qualified name of insecure registries. An insecure registry is a registry that does not have a valid SSL certificate or only supports HTTP.
registry-block	string	The registries that need to block pull access.	“”

kaniko

The kaniko ClusterBuildStrategy uses kaniko to build application images.

To use kaniko ClusterBuildStrategy, you can define a Function like this:

apiVersion: core.openfunction.io/v1beta2
kind: Function
metadata:
  name: function-kaniko
  namespace: default
spec:
  build:
    builder: openfunction/kaniko-executor:v1.7.0
    dockerfile: Dockerfile
    shipwright:
      strategy:
        kind: ClusterBuildStrategy
        name: kaniko

ko

The ko ClusterBuildStrategy uses ko to build Go application images.

To use ko ClusterBuildStrategy, you can define a Function like this:

apiVersion: core.openfunction.io/v1beta2
kind: Function
metadata:
  name: function-ko
  namespace: default
spec:
  build:
    builder: golang:1.17
    dockerfile: Dockerfile
    shipwright:
      strategy:
        kind: ClusterBuildStrategy
        name: ko

The following are the parameters of ko ClusterBuildStrategy:

Name	Type	Describe	Default
go-flags	string	Value for the GOFLAGS environment variable.	“”
ko-version	string	Version of ko, must be either ’latest’, or a release name from https://github.com/google/ko/releases.	“”
package-directory	string	The directory inside the context directory containing the main package.	“.”

Custom Strategy

Users can customize their own strategy. To customize strategy, you can refer to this.