builder/docker: boilerplate

builder/docker/builder.go

+package docker
+
+import (
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/packer"
+	"log"
+)
+
+const BuilderId = "packer.docker"
+
+type Builder struct {
+	config Config
+	runner multistep.Runner
+}
+
+func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
+	md, err := common.DecodeConfig(&b.config, raws...)
+	if err != nil {
+		return nil, err
+	}
+
+	b.config.tpl, err = packer.NewConfigTemplate()
+	if err != nil {
+		return nil, err
+	}
+
+	errs := common.CheckUnusedConfig(md)
+	warnings := make([]string, 0)
+
+	if errs != nil && len(errs.Errors) > 0 {
+		return warnings, errs
+	}
+
+	return warnings, nil
+}
+
+func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {
+	steps := []multistep.Step{}
+
+	// Setup the state bag and initial state for the steps
+	state := new(multistep.BasicStateBag)
+	state.Put("config", &b.config)
+
+	// Run!
+	if b.config.PackerDebug {
+		b.runner = &multistep.DebugRunner{
+			Steps:   steps,
+			PauseFn: common.MultistepDebugFn(ui),
+		}
+	} else {
+		b.runner = &multistep.BasicRunner{Steps: steps}
+	}
+
+	b.runner.Run(state)
+
+	// If there was an error, return that
+	if rawErr, ok := state.GetOk("error"); ok {
+		return nil, rawErr.(error)
+	}
+
+	return nil, nil
+}
+
+func (b *Builder) Cancel() {
+	if b.runner != nil {
+		log.Println("Cancelling the step runner...")
+		b.runner.Cancel()
+	}
+}

builder/docker/builder_test.go

+package docker
+
+import (
+	"github.com/mitchellh/packer/packer"
+	"testing"
+)
+
+func TestBuilder_implBuilder(t *testing.T) {
+	var _ packer.Builder = new(Builder)
+}

builder/docker/config.go

+package docker
+
+import (
+	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/packer"
+)
+
+type Config struct {
+	common.PackerConfig `mapstructure:",squash"`
+
+	tpl *packer.ConfigTemplate
+}