func (s *uniterResolver) nextOp(
localState resolver.LocalState,
remoteState remotestate.Snapshot,
opFactory operation.Factory,
) (operation.Operation, error) {
switch remoteState.Life {
case params.Alive:
case params.Dying:
// Normally we handle relations last, but if we're dying we
// must ensure that all relations are broken first.
op, err := s.config.Relations.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
// We're not in a hook error and the unit is Dying,
// so we should proceed to tear down.
//
// TODO(axw) move logic for cascading destruction of
// subordinates, relation units and storage
// attachments into state, via cleanups.
if localState.Started {
return opFactory.NewRunHook(hook.Info{Kind: hooks.Stop})
}
fallthrough
case params.Dead:
// The unit is dying/dead and stopped, so tell the uniter
// to terminate.
return nil, resolver.ErrTerminate
}
// Now that storage hooks have run at least once, before anything else,
// we need to run the install hook.
// TODO(cmars): remove !localState.Started. It's here as a temporary
// measure because unit agent upgrades aren't being performed yet.
if !localState.Installed && !localState.Started {
return opFactory.NewRunHook(hook.Info{Kind: hooks.Install})
}
if charmModified(localState, remoteState) {
return opFactory.NewUpgrade(remoteState.CharmURL)
}
if localState.ConfigVersion != remoteState.ConfigVersion {
return opFactory.NewRunHook(hook.Info{Kind: hooks.ConfigChanged})
}
op, err := s.config.Relations.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
// UpdateStatus hook runs if nothing else needs to.
if localState.UpdateStatusVersion != remoteState.UpdateStatusVersion {
return opFactory.NewRunHook(hook.Info{Kind: hooks.UpdateStatus})
}
return nil, resolver.ErrNoOperation
}
func (s *uniterResolver) nextOpHookError(
localState resolver.LocalState,
remoteState remotestate.Snapshot,
opFactory operation.Factory,
) (operation.Operation, error) {
// Report the hook error.
if err := s.reportHookError(*localState.Hook); err != nil {
return nil, errors.Trace(err)
}
if remoteState.ForceCharmUpgrade && *localState.CharmURL != *remoteState.CharmURL {
logger.Debugf("upgrade from %v to %v", localState.CharmURL, remoteState.CharmURL)
return opFactory.NewUpgrade(remoteState.CharmURL)
}
switch remoteState.ResolvedMode {
case params.ResolvedNone:
return nil, resolver.ErrNoOperation
case params.ResolvedRetryHooks:
if err := s.clearResolved(); err != nil {
return nil, errors.Trace(err)
}
return opFactory.NewRunHook(*localState.Hook)
case params.ResolvedNoHooks:
if err := s.clearResolved(); err != nil {
return nil, errors.Trace(err)
}
return opFactory.NewSkipHook(*localState.Hook)
default:
return nil, errors.Errorf(
"unknown resolved mode %q", remoteState.ResolvedMode,
)
}
}
func (s *uniterResolver) nextOpHookError(
localState resolver.LocalState,
remoteState remotestate.Snapshot,
opFactory operation.Factory,
) (operation.Operation, error) {
// Report the hook error.
if err := s.config.ReportHookError(*localState.Hook); err != nil {
return nil, errors.Trace(err)
}
if remoteState.ForceCharmUpgrade && *localState.CharmURL != *remoteState.CharmURL {
logger.Debugf("upgrade from %v to %v", localState.CharmURL, remoteState.CharmURL)
return opFactory.NewUpgrade(remoteState.CharmURL)
}
switch remoteState.ResolvedMode {
case params.ResolvedNone:
if remoteState.RetryHookVersion > localState.RetryHookVersion {
// We've been asked to retry: clear the hook timer
// started state so we'll restart it if this fails.
//
// If the hook fails again, we'll re-enter this method
// with the retry hook versions equal and restart the
// timer. If the hook succeeds, we'll enter nextOp
// and stop the timer.
s.retryHookTimerStarted = false
return opFactory.NewRunHook(*localState.Hook)
}
if !s.retryHookTimerStarted {
// We haven't yet started a retry timer, so start one
// now. If we retry and fail, retryHookTimerStarted is
// cleared so that we'll still start it again.
s.config.StartRetryHookTimer()
s.retryHookTimerStarted = true
}
return nil, resolver.ErrNoOperation
case params.ResolvedRetryHooks:
s.config.StopRetryHookTimer()
s.retryHookTimerStarted = false
if err := s.config.ClearResolved(); err != nil {
return nil, errors.Trace(err)
}
return opFactory.NewRunHook(*localState.Hook)
case params.ResolvedNoHooks:
s.config.StopRetryHookTimer()
s.retryHookTimerStarted = false
if err := s.config.ClearResolved(); err != nil {
return nil, errors.Trace(err)
}
return opFactory.NewSkipHook(*localState.Hook)
default:
return nil, errors.Errorf(
"unknown resolved mode %q", remoteState.ResolvedMode,
)
}
}
func (s *uniterResolver) NextOp(
localState resolver.LocalState,
remoteState remotestate.Snapshot,
opFactory operation.Factory,
) (operation.Operation, error) {
if remoteState.Life == params.Dead || localState.Stopped {
return nil, resolver.ErrTerminate
}
if localState.Kind == operation.Upgrade {
if localState.Conflicted {
return s.nextOpConflicted(localState, remoteState, opFactory)
}
logger.Infof("resuming charm upgrade")
return opFactory.NewUpgrade(localState.CharmURL)
}
if localState.Restart {
// We've just run the upgrade op, which will change the
// unit's charm URL. We need to restart the resolver
// loop so that we start watching the correct events.
return nil, resolver.ErrRestart
}
if s.retryHookTimerStarted && (localState.Kind != operation.RunHook || localState.Step != operation.Pending) {
// The hook-retry timer is running, but there is no pending
// hook operation. We're not in an error state, so stop the
// timer now to reset the backoff state.
s.config.StopRetryHookTimer()
s.retryHookTimerStarted = false
}
op, err := s.config.Leadership.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
op, err = s.config.Actions.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
op, err = s.config.Commands.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
op, err = s.config.Storage.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
switch localState.Kind {
case operation.RunHook:
switch localState.Step {
case operation.Pending:
logger.Infof("awaiting error resolution for %q hook", localState.Hook.Kind)
return s.nextOpHookError(localState, remoteState, opFactory)
case operation.Queued:
logger.Infof("found queued %q hook", localState.Hook.Kind)
if localState.Hook.Kind == hooks.Install {
// Special case: handle install in nextOp,
// so we do nothing when the unit is dying.
return s.nextOp(localState, remoteState, opFactory)
}
return opFactory.NewRunHook(*localState.Hook)
case operation.Done:
logger.Infof("committing %q hook", localState.Hook.Kind)
return opFactory.NewSkipHook(*localState.Hook)
default:
return nil, errors.Errorf("unknown operation step %v", localState.Step)
}
case operation.Continue:
logger.Infof("no operations in progress; waiting for changes")
return s.nextOp(localState, remoteState, opFactory)
default:
return nil, errors.Errorf("unknown operation kind %v", localState.Kind)
}
}
func (s *uniterResolver) NextOp(
localState resolver.LocalState,
remoteState remotestate.Snapshot,
opFactory operation.Factory,
) (operation.Operation, error) {
if remoteState.Life == params.Dead || localState.Stopped {
return nil, resolver.ErrTerminate
}
if localState.Kind == operation.Upgrade {
if localState.Conflicted {
return s.nextOpConflicted(localState, remoteState, opFactory)
}
logger.Infof("resuming charm upgrade")
return opFactory.NewUpgrade(localState.CharmURL)
}
if localState.Restart {
// We've just run the upgrade op, which will change the
// unit's charm URL. We need to restart the resolver
// loop so that we start watching the correct events.
return nil, resolver.ErrRestart
}
if localState.Kind == operation.Continue {
if err := s.fixDeployer(); err != nil {
return nil, errors.Trace(err)
}
}
op, err := s.leadershipResolver.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
op, err = s.actionsResolver.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
op, err = s.storageResolver.NextOp(localState, remoteState, opFactory)
if errors.Cause(err) != resolver.ErrNoOperation {
return op, err
}
switch localState.Kind {
case operation.RunHook:
switch localState.Step {
case operation.Pending:
logger.Infof("awaiting error resolution for %q hook", localState.Hook.Kind)
return s.nextOpHookError(localState, remoteState, opFactory)
case operation.Queued:
logger.Infof("found queued %q hook", localState.Hook.Kind)
if localState.Hook.Kind == hooks.Install {
// Special case: handle install in nextOp,
// so we do nothing when the unit is dying.
return s.nextOp(localState, remoteState, opFactory)
}
return opFactory.NewRunHook(*localState.Hook)
case operation.Done:
logger.Infof("committing %q hook", localState.Hook.Kind)
return opFactory.NewSkipHook(*localState.Hook)
default:
return nil, errors.Errorf("unknown operation step %v", localState.Step)
}
case operation.Continue:
logger.Infof("no operations in progress; waiting for changes")
return s.nextOp(localState, remoteState, opFactory)
default:
return nil, errors.Errorf("unknown operation kind %v", localState.Kind)
}
}