// upgradeWaiterWorker runs the specified worker after upgrades have completed.
func (a *MachineAgent) upgradeWaiterWorker(start func() (worker.Worker, error)) worker.Worker {
return worker.NewSimpleWorker(func(stop <-chan struct{}) error {
// wait for the upgrade to complete (or for us to be stopped)
select {
case <-stop:
return nil
case <-a.upgradeComplete:
}
w, err := start()
if err != nil {
return err
}
waitCh := make(chan error)
go func() {
waitCh <- w.Wait()
}()
select {
case err := <-waitCh:
return err
case <-stop:
w.Kill()
}
return <-waitCh
})
}
// upgradeWorker runs the required upgrade operations to upgrade to the current Juju version.
func (a *MachineAgent) upgradeWorker(
apiState *api.State,
jobs []params.MachineJob,
agentConfig agent.Config,
) worker.Worker {
return worker.NewSimpleWorker(func(stop <-chan struct{}) error {
select {
case <-a.upgradeComplete:
// Our work is already done (we're probably being restarted
// because the API connection has gone down), so do nothing.
<-stop
return nil
default:
}
// If the machine agent is a state server, wait until state is opened.
needsState := false
for _, job := range jobs {
if job == params.JobManageEnviron {
needsState = true
}
}
// We need a *state.State for upgrades. We open it independently
// of StateWorker, because we have no guarantees about when
// and how often StateWorker might run.
var st *state.State
if needsState {
var err error
info, ok := agentConfig.StateInfo()
if !ok {
return fmt.Errorf("no state info available")
}
st, err = state.Open(info, state.DialOpts{}, environs.NewStatePolicy())
if err != nil {
return err
}
defer st.Close()
}
err := a.runUpgrades(st, apiState, jobs, agentConfig)
if err != nil {
return err
}
logger.Infof("upgrade to %v completed.", version.Current)
close(a.upgradeComplete)
<-stop
return nil
})
}
func newDummyWorker() worker.Worker {
return worker.NewSimpleWorker(func(stop <-chan struct{}) error {
<-stop
return nil
})
}
// newStateStarterWorker wraps stateStarter in a simple worker for use in
// a.runner.StartWorker.
func (a *MachineAgent) newStateStarterWorker() (worker.Worker, error) {
return worker.NewSimpleWorker(a.stateStarter), nil
}