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

314 lines
9.3 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"
"log"
"runtime"
"github.com/aws/aws-sdk-go/service/ec2"
awscommon "github.com/hashicorp/packer/builder/amazon/common"
"github.com/hashicorp/packer/common"
"github.com/hashicorp/packer/helper/config"
"github.com/hashicorp/packer/packer"
"github.com/hashicorp/packer/template/interpolate"
"github.com/mitchellh/multistep"
)
// 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.AMIBlockDevices `mapstructure:",squash"`
awscommon.AMIConfig `mapstructure:",squash"`
awscommon.AccessConfig `mapstructure:",squash"`
ChrootMounts [][]string `mapstructure:"chroot_mounts"`
CommandWrapper string `mapstructure:"command_wrapper"`
CopyFiles []string `mapstructure:"copy_files"`
DevicePath string `mapstructure:"device_path"`
FromScratch bool `mapstructure:"from_scratch"`
MountOptions []string `mapstructure:"mount_options"`
MountPartition int `mapstructure:"mount_partition"`
MountPath string `mapstructure:"mount_path"`
PostMountCommands []string `mapstructure:"post_mount_commands"`
PreMountCommands []string `mapstructure:"pre_mount_commands"`
RootDeviceName string `mapstructure:"root_device_name"`
RootVolumeSize int64 `mapstructure:"root_volume_size"`
SourceAmi string `mapstructure:"source_ami"`
SourceAmiFilter awscommon.AmiFilterOptions `mapstructure:"source_ami_filter"`
ctx interpolate.Context
}
type wrappedCommandTemplate struct {
Command string
}
type Builder struct {
config Config
runner multistep.Runner
}
func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
b.config.ctx.Funcs = awscommon.TemplateFuncs
err := config.Decode(&b.config, &config.DecodeOpts{
Interpolate: true,
InterpolateContext: &b.config.ctx,
InterpolateFilter: &interpolate.RenderFilter{
Exclude: []string{
"ami_description",
"snapshot_tags",
"tags",
"command_wrapper",
"post_mount_commands",
"pre_mount_commands",
"mount_path",
},
},
}, raws...)
if err != nil {
return nil, err
}
if b.config.PackerConfig.PackerForce {
b.config.AMIForceDeregister = true
}
// Defaults
if b.config.ChrootMounts == nil {
b.config.ChrootMounts = make([][]string, 0)
}
if len(b.config.ChrootMounts) == 0 {
b.config.ChrootMounts = [][]string{
{"proc", "proc", "/proc"},
{"sysfs", "sysfs", "/sys"},
{"bind", "/dev", "/dev"},
{"devpts", "devpts", "/dev/pts"},
{"binfmt_misc", "binfmt_misc", "/proc/sys/fs/binfmt_misc"},
}
}
// set default copy file if we're not giving our own
if b.config.CopyFiles == nil {
b.config.CopyFiles = make([]string, 0)
if !b.config.FromScratch {
b.config.CopyFiles = []string{"/etc/resolv.conf"}
}
}
if b.config.CommandWrapper == "" {
b.config.CommandWrapper = "{{.Command}}"
}
if b.config.MountPath == "" {
b.config.MountPath = "/mnt/packer-amazon-chroot-volumes/{{.Device}}"
}
if b.config.MountPartition == 0 {
b.config.MountPartition = 1
}
// Accumulate any errors or warnings
var errs *packer.MultiError
var warns []string
errs = packer.MultiErrorAppend(errs, b.config.AccessConfig.Prepare(&b.config.ctx)...)
errs = packer.MultiErrorAppend(errs, b.config.AMIConfig.Prepare(&b.config.ctx)...)
for _, mounts := range b.config.ChrootMounts {
if len(mounts) != 3 {
errs = packer.MultiErrorAppend(
errs, errors.New("Each chroot_mounts entry should be three elements."))
break
}
}
if b.config.FromScratch {
if b.config.SourceAmi != "" || !b.config.SourceAmiFilter.Empty() {
warns = append(warns, "source_ami and source_ami_filter are unused when from_scratch is true")
}
if b.config.RootVolumeSize == 0 {
errs = packer.MultiErrorAppend(
errs, errors.New("root_volume_size is required with from_scratch."))
}
if len(b.config.PreMountCommands) == 0 {
errs = packer.MultiErrorAppend(
errs, errors.New("pre_mount_commands is required with from_scratch."))
}
if b.config.AMIVirtType == "" {
errs = packer.MultiErrorAppend(
errs, errors.New("ami_virtualization_type is required with from_scratch."))
}
if b.config.RootDeviceName == "" {
errs = packer.MultiErrorAppend(
errs, errors.New("root_device_name is required with from_scratch."))
}
if len(b.config.AMIMappings) == 0 {
errs = packer.MultiErrorAppend(
errs, errors.New("ami_block_device_mappings is required with from_scratch."))
}
} else {
if b.config.SourceAmi == "" && b.config.SourceAmiFilter.Empty() {
errs = packer.MultiErrorAppend(
errs, errors.New("source_ami or source_ami_filter is required."))
}
if len(b.config.AMIMappings) != 0 {
warns = append(warns, "ami_block_device_mappings are unused when from_scratch is false")
}
if b.config.RootDeviceName != "" {
warns = append(warns, "root_device_name is unused when from_scratch is false")
}
}
if errs != nil && len(errs.Errors) > 0 {
return warns, errs
}
log.Println(common.ScrubConfig(b.config, b.config.AccessKey, b.config.SecretKey))
return warns, 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.")
}
session, err := b.config.Session()
if err != nil {
return nil, err
}
ec2conn := ec2.New(session)
wrappedCommand := func(command string) (string, error) {
ctx := b.config.ctx
ctx.Data = &wrappedCommandTemplate{Command: command}
return interpolate.Render(b.config.CommandWrapper, &ctx)
}
// Setup the state bag and initial state for the steps
state := new(multistep.BasicStateBag)
state.Put("config", &b.config)
state.Put("ec2", ec2conn)
state.Put("hook", hook)
state.Put("ui", ui)
state.Put("wrappedCommand", CommandWrapper(wrappedCommand))
// Build the steps
steps := []multistep.Step{
&awscommon.StepPreValidate{
DestAmiName: b.config.AMIName,
ForceDeregister: b.config.AMIForceDeregister,
},
&StepInstanceInfo{},
}
if !b.config.FromScratch {
steps = append(steps,
&awscommon.StepSourceAMIInfo{
SourceAmi: b.config.SourceAmi,
EnhancedNetworking: b.config.AMIEnhancedNetworking,
AmiFilters: b.config.SourceAmiFilter,
},
&StepCheckRootDevice{},
)
}
steps = append(steps,
&StepFlock{},
&StepPrepareDevice{},
&StepCreateVolume{
RootVolumeSize: b.config.RootVolumeSize,
},
&StepAttachVolume{},
&StepEarlyUnflock{},
&StepPreMountCommands{
Commands: b.config.PreMountCommands,
},
&StepMountDevice{
MountOptions: b.config.MountOptions,
MountPartition: b.config.MountPartition,
},
&StepPostMountCommands{
Commands: b.config.PostMountCommands,
},
&StepMountExtra{},
&StepCopyFiles{},
&StepChrootProvision{},
&StepEarlyCleanup{},
&StepSnapshot{},
&awscommon.StepDeregisterAMI{
ForceDeregister: b.config.AMIForceDeregister,
ForceDeleteSnapshot: b.config.AMIForceDeleteSnapshot,
AMIName: b.config.AMIName,
},
&StepRegisterAMI{
RootVolumeSize: b.config.RootVolumeSize,
},
&awscommon.StepCreateEncryptedAMICopy{
KeyID: b.config.AMIKmsKeyId,
EncryptBootVolume: b.config.AMIEncryptBootVolume,
Name: b.config.AMIName,
AMIMappings: b.config.AMIBlockDevices.AMIMappings,
},
&awscommon.StepAMIRegionCopy{
AccessConfig: &b.config.AccessConfig,
Regions: b.config.AMIRegions,
RegionKeyIds: b.config.AMIRegionKMSKeyIDs,
EncryptBootVolume: b.config.AMIEncryptBootVolume,
Name: b.config.AMIName,
},
&awscommon.StepModifyAMIAttributes{
Description: b.config.AMIDescription,
Users: b.config.AMIUsers,
Groups: b.config.AMIGroups,
ProductCodes: b.config.AMIProductCodes,
SnapshotUsers: b.config.SnapshotUsers,
SnapshotGroups: b.config.SnapshotGroups,
Ctx: b.config.ctx,
},
&awscommon.StepCreateTags{
Tags: b.config.AMITags,
SnapshotTags: b.config.SnapshotTags,
Ctx: b.config.ctx,
},
)
// Run!
b.runner = common.NewRunner(steps, b.config.PackerConfig, ui)
b.runner.Run(state)
// If there was an error, return that
if rawErr, ok := state.GetOk("error"); ok {
return nil, rawErr.(error)
}
// If there are no AMIs, then just return
if _, ok := state.GetOk("amis"); !ok {
return nil, nil
}
// Build the artifact and return it
artifact := &awscommon.Artifact{
Amis: state.Get("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()
}
}