packer-cn/packer/build.go

98 lines
2.4 KiB
Go

package packer
import "log"
// A Build represents a single job within Packer that is responsible for
// building some machine image artifact. Builds are meant to be parallelized.
type Build interface {
Name() string
Prepare() error
Run(Ui, Cache) (Artifact, error)
Cancel()
}
// A build struct represents a single build job, the result of which should
// be a single machine image artifact. This artifact may be comprised of
// multiple files, of course, but it should be for only a single provider
// (such as VirtualBox, EC2, etc.).
type coreBuild struct {
name string
builder Builder
builderConfig interface{}
hooks map[string][]Hook
provisioners []coreBuildProvisioner
prepareCalled bool
}
// Keeps track of the provisioner and the configuration of the provisioner
// within the build.
type coreBuildProvisioner struct {
provisioner Provisioner
config []interface{}
}
// Returns the name of the build.
func (b *coreBuild) Name() string {
return b.name
}
// Prepare prepares the build by doing some initialization for the builder
// and any hooks. This _must_ be called prior to Run.
func (b *coreBuild) Prepare() (err error) {
// TODO: lock
b.prepareCalled = true
// Prepare the builder
err = b.builder.Prepare(b.builderConfig)
if err != nil {
log.Printf("Build '%s' prepare failure: %s\n", b.name, err)
return
}
// Prepare the provisioners
for _, coreProv := range b.provisioners {
if err = coreProv.provisioner.Prepare(coreProv.config...); err != nil {
return
}
}
return
}
// Runs the actual build. Prepare must be called prior to running this.
func (b *coreBuild) Run(ui Ui, cache Cache) (Artifact, error) {
if !b.prepareCalled {
panic("Prepare must be called first")
}
// Copy the hooks
hooks := make(map[string][]Hook)
for hookName, hookList := range b.hooks {
hooks[hookName] = make([]Hook, len(hookList))
copy(hooks[hookName], hookList)
}
// Add a hook for the provisioners if we have provisioners
if len(b.provisioners) > 0 {
provisioners := make([]Provisioner, len(b.provisioners))
for i, p := range b.provisioners {
provisioners[i] = p.provisioner
}
if _, ok := hooks[HookProvision]; !ok {
hooks[HookProvision] = make([]Hook, 0, 1)
}
hooks[HookProvision] = append(hooks[HookProvision], &ProvisionHook{provisioners})
}
hook := &DispatchHook{hooks}
return b.builder.Run(ui, hook, cache)
}
// Cancels the build if it is running.
func (b *coreBuild) Cancel() {
b.builder.Cancel()
}