// lazyCreateUnits iterates over a set of unit names and, for each, attempts to
// ensure that a unit by that name exists in the Registry, by checking a number
// of conditions and acting on the first one that succeeds, in order of:
// 1. a unit by that name already existing in the Registry
// 2. a unit file by that name existing on disk
// 3. a corresponding unit template (if applicable) existing in the Registry
// 4. a corresponding unit template (if applicable) existing on disk
// Any error encountered during these steps is returned immediately (i.e.
// subsequent Jobs are not acted on). An error is also returned if none of the
// above conditions match a given Job.
func (f *FleetTunnel) lazyCreateUnits(units UnitDataList, events chan Event) error {
errchan := make(chan error)
blockAttempts := f.BlockAttempts
var wg sync.WaitGroup
for i := 0; i < units.Len(); i++ {
u := units.Get(i)
name := u.Name()
create, err := f.checkUnitCreation(name)
if err != nil {
return err
} else if !create {
continue
}
// Assume that the name references a local unit file on
// disk or if it is an instance unit and if so get its
// corresponding unit
uf, err := unit.NewUnitFile(u.Content())
if err != nil {
return err
}
events <- newEvent(name, "creating unit")
_, err = f.createUnit(name, uf)
if err != nil {
return err
}
wg.Add(1)
go f.checkUnitState(name, job.JobStateInactive, blockAttempts, events, &wg, errchan)
}
go func() {
wg.Wait()
close(errchan)
}()
var ae aerr.AggregateError
for msg := range errchan {
ae.Add(maskAny(fmt.Errorf("Error waiting on unit creation: %v\n", msg)))
}
if !ae.IsEmpty() {
return maskAny(&ae)
}
return nil
}
// tryWaitForUnitStates tries to wait for units to reach the desired state.
// It takes 5 arguments, the units to wait for, the desired state, the
// desired JobState, how many attempts before timing out and a writer
// interface.
// tryWaitForUnitStates polls each of the indicated units until they
// reach the desired state. If maxAttempts is negative, then it will not
// wait, it will assume that all units reached their desired state.
// If maxAttempts is zero tryWaitForUnitStates will retry forever, and
// if it is greater than zero, it will retry up to the indicated value.
// It returns 0 on success or 1 on errors.
func (f *FleetTunnel) tryWaitForUnitStates(units []string, state string, js job.JobState, maxAttempts int, events chan Event) error {
// We do not wait just assume we reached the desired state
if maxAttempts <= -1 {
for _, name := range units {
events <- newEvent(name, fmt.Sprintf("triggered %s", name))
}
return nil
}
errchan := f.waitForUnitStates(units, js, maxAttempts, events)
var ae aerr.AggregateError
for err := range errchan {
ae.Add(maskAny(err))
}
if !ae.IsEmpty() {
return maskAny(&ae)
}
return nil
}
func (f *FleetTunnel) Destroy(events chan Event, unitNames ...string) error {
log.Debugf("destroying %v", unitNames)
var ae aerr.AggregateError
for _, unit := range unitNames {
events <- newEvent(unit, "destroying")
if notFound, err := f.destroyUnitWithRetry(unit); notFound {
continue
} else if err != nil {
ae.Add(maskAny(fmt.Errorf("Error destroying units: %v", err)))
continue
}
if f.NoBlock {
attempts := f.BlockAttempts
retry := func() bool {
if f.BlockAttempts < 1 {
return true
}
attempts--
if attempts == 0 {
return false
}
return true
}
for retry() {
exists, err := f.unitExists(unit)
if err != nil {
ae.Add(maskAny(fmt.Errorf("Error destroying units: %v", err)))
break
}
if !exists {
break
}
time.Sleep(defaultSleepTime)
}
}
events <- newEvent(unit, "destroyed")
}
if !ae.IsEmpty() {
return maskAny(&ae)
}
return nil
}