packer-cn/builder/amazon/chroot/builder.go

125 lines
2.8 KiB
Go

// The chroot package is able to create an Amazon AMI without requiring
// the launch of a new instance for every build. It does this by attaching
// and mounting the root volume of another AMI and chrooting into that
// directory. It then creates an AMI from that attached drive.
package chroot
import (
"errors"
"github.com/mitchellh/goamz/ec2"
"github.com/mitchellh/multistep"
awscommon "github.com/mitchellh/packer/builder/amazon/common"
"github.com/mitchellh/packer/builder/common"
"github.com/mitchellh/packer/packer"
"log"
"runtime"
)
// The unique ID for this builder
const BuilderId = "mitchellh.amazon.chroot"
// Config is the configuration that is chained through the steps and
// settable from the template.
type Config struct {
common.PackerConfig `mapstructure:",squash"`
awscommon.AccessConfig `mapstructure:",squash"`
SourceAmi string `mapstructure:"source_ami"`
}
type Builder struct {
config Config
runner multistep.Runner
}
func (b *Builder) Prepare(raws ...interface{}) error {
md, err := common.DecodeConfig(&b.config, raws...)
if err != nil {
return err
}
// Defaults
// Accumulate any errors
errs := common.CheckUnusedConfig(md)
errs = packer.MultiErrorAppend(errs, b.config.AccessConfig.Prepare()...)
if errs != nil && len(errs.Errors) > 0 {
return errs
}
log.Printf("Config: %+v", b.config)
return nil
}
func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {
if runtime.GOOS != "linux" {
return nil, errors.New("The amazon-chroot builder only works on Linux environments.")
}
region, err := b.config.Region()
if err != nil {
return nil, err
}
auth, err := b.config.AccessConfig.Auth()
if err != nil {
return nil, err
}
ec2conn := ec2.New(auth, region)
// Setup the state bag and initial state for the steps
state := make(map[string]interface{})
state["config"] = &b.config
state["ec2"] = ec2conn
state["hook"] = hook
state["ui"] = ui
// Build the steps
steps := []multistep.Step{
&StepInstanceInfo{},
&StepSourceAMIInfo{},
&StepCreateVolume{},
&StepAttachVolume{},
}
// 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["error"]; ok {
return nil, rawErr.(error)
}
// If there are no AMIs, then just return
if _, ok := state["amis"]; !ok {
return nil, nil
}
// Build the artifact and return it
artifact := &awscommon.Artifact{
Amis: state["amis"].(map[string]string),
BuilderIdValue: BuilderId,
Conn: ec2conn,
}
return artifact, nil
}
func (b *Builder) Cancel() {
if b.runner != nil {
log.Println("Cancelling the step runner...")
b.runner.Cancel()
}
}