packer-cn/packer/provisioner.go

68 lines
1.7 KiB
Go

package packer
import (
"sync"
)
// A provisioner is responsible for installing and configuring software
// on a machine prior to building the actual image.
type Provisioner interface {
// Prepare is called with a set of configurations to setup the
// internal state of the provisioner. The multiple configurations
// should be merged in some sane way.
Prepare(...interface{}) error
// Provision is called to actually provision the machine. A UI is
// given to communicate with the user, and a communicator is given that
// is guaranteed to be connected to some machine so that provisioning
// can be done.
Provision(Ui, Communicator) error
// Cancel is called to cancel the provisioning. This is usually called
// while Provision is still being called. The Provisioner should act
// to stop its execution as quickly as possible in a race-free way.
Cancel()
}
// A Hook implementation that runs the given provisioners.
type ProvisionHook struct {
// The provisioners to run as part of the hook. These should already
// be prepared (by calling Prepare) at some earlier stage.
Provisioners []Provisioner
lock sync.Mutex
runningProvisioner Provisioner
}
// Runs the provisioners in order.
func (h *ProvisionHook) Run(name string, ui Ui, comm Communicator, data interface{}) error {
defer func() {
h.lock.Lock()
defer h.lock.Unlock()
h.runningProvisioner = nil
}()
for _, p := range h.Provisioners {
h.lock.Lock()
h.runningProvisioner = p
h.lock.Unlock()
if err := p.Provision(ui, comm); err != nil {
return err
}
}
return nil
}
// Cancels the privisioners that are still running.
func (h *ProvisionHook) Cancel() {
h.lock.Lock()
defer h.lock.Unlock()
if h.runningProvisioner != nil {
h.runningProvisioner.Cancel()
}
}