func stopWatcher(c *gc.C, w apiwatcher.NotifyWatcher) {
err := w.Stop()
c.Check(err, jc.ErrorIsNil)
}
func (f *filter) loop(unitTag string) (err error) {
// TODO(dfc) named return value is a time bomb
defer func() {
if params.IsCodeNotFoundOrCodeUnauthorized(err) {
err = worker.ErrTerminateAgent
}
}()
tag, err := names.ParseUnitTag(unitTag)
if err != nil {
return err
}
if f.unit, err = f.st.Unit(tag); err != nil {
return err
}
if err = f.unitChanged(); err != nil {
return err
}
f.service, err = f.unit.Service()
if err != nil {
return err
}
if err = f.serviceChanged(); err != nil {
return err
}
unitw, err := f.unit.Watch()
if err != nil {
return err
}
defer f.maybeStopWatcher(unitw)
servicew, err := f.service.Watch()
if err != nil {
return err
}
defer f.maybeStopWatcher(servicew)
// configw and relationsw can get restarted, so we need to use
// their eventual values in the defer calls.
var configw apiwatcher.NotifyWatcher
var configChanges <-chan struct{}
curl, err := f.unit.CharmURL()
if err == nil {
configw, err = f.unit.WatchConfigSettings()
if err != nil {
return err
}
configChanges = configw.Changes()
f.upgradeFrom.url = curl
} else if err != uniter.ErrNoCharmURLSet {
filterLogger.Errorf("unit charm: %v", err)
return err
}
defer func() {
if configw != nil {
watcher.Stop(configw, &f.tomb)
}
}()
actionsw, err := f.unit.WatchActions()
if err != nil {
return err
}
f.actionsPending = make([]string, 0)
defer func() {
if actionsw != nil {
watcher.Stop(actionsw, &f.tomb)
}
}()
relationsw, err := f.service.WatchRelations()
if err != nil {
return err
}
defer func() {
if relationsw != nil {
watcher.Stop(relationsw, &f.tomb)
}
}()
var addressChanges <-chan struct{}
addressesw, err := f.unit.WatchAddresses()
if err != nil {
return err
}
defer watcher.Stop(addressesw, &f.tomb)
// Config events cannot be meaningfully discarded until one is available;
// once we receive the initial change, we unblock discard requests by
// setting this channel to its namesake on f.
var discardConfig chan struct{}
for {
var ok bool
select {
case <-f.tomb.Dying():
return tomb.ErrDying
// Handle watcher changes.
case _, ok = <-unitw.Changes():
filterLogger.Debugf("got unit change")
if !ok {
return watcher.MustErr(unitw)
}
if err = f.unitChanged(); err != nil {
return err
}
case _, ok = <-servicew.Changes():
filterLogger.Debugf("got service change")
if !ok {
return watcher.MustErr(servicew)
}
if err = f.serviceChanged(); err != nil {
return err
}
case _, ok = <-configChanges:
filterLogger.Debugf("got config change")
if !ok {
return watcher.MustErr(configw)
}
if addressChanges == nil {
// We start reacting to address changes after the
// first config-changed is processed, ignoring the
// initial address changed event.
addressChanges = addressesw.Changes()
if _, ok := <-addressChanges; !ok {
return watcher.MustErr(addressesw)
}
}
filterLogger.Debugf("preparing new config event")
f.outConfig = f.outConfigOn
discardConfig = f.discardConfig
case _, ok = <-addressChanges:
filterLogger.Debugf("got address change")
if !ok {
return watcher.MustErr(addressesw)
}
// address change causes config-changed event
filterLogger.Debugf("preparing new config event")
f.outConfig = f.outConfigOn
case ids, ok := <-actionsw.Changes():
filterLogger.Debugf("got %d actions", len(ids))
if !ok {
return watcher.MustErr(actionsw)
}
f.actionsPending = append(f.actionsPending, ids...)
f.nextAction = f.getNextAction()
case keys, ok := <-relationsw.Changes():
filterLogger.Debugf("got relations change")
if !ok {
return watcher.MustErr(relationsw)
}
var ids []int
for _, key := range keys {
relationTag := names.NewRelationTag(key).String()
rel, err := f.st.Relation(relationTag)
if params.IsCodeNotFoundOrCodeUnauthorized(err) {
// If it's actually gone, this unit cannot have entered
// scope, and therefore never needs to know about it.
} else if err != nil {
return err
} else {
ids = append(ids, rel.Id())
}
}
f.relationsChanged(ids)
// Send events on active out chans.
case f.outUpgrade <- f.upgrade:
filterLogger.Debugf("sent upgrade event")
f.outUpgrade = nil
case f.outResolved <- f.resolved:
filterLogger.Debugf("sent resolved event")
f.outResolved = nil
case f.outConfig <- nothing:
filterLogger.Debugf("sent config event")
f.outConfig = nil
case f.outAction <- f.nextAction:
f.nextAction = f.getNextAction()
filterLogger.Debugf("sent action event")
case f.outRelations <- f.relations:
filterLogger.Debugf("sent relations event")
f.outRelations = nil
f.relations = nil
// Handle explicit requests.
case curl := <-f.setCharm:
filterLogger.Debugf("changing charm to %q", curl)
// We need to restart the config watcher after setting the
// charm, because service config settings are distinct for
// different service charms.
if configw != nil {
if err := configw.Stop(); err != nil {
return err
}
}
if err := f.unit.SetCharmURL(curl); err != nil {
filterLogger.Debugf("failed setting charm url %q: %v", curl, err)
return err
}
select {
case <-f.tomb.Dying():
return tomb.ErrDying
case f.didSetCharm <- nothing:
}
configw, err = f.unit.WatchConfigSettings()
if err != nil {
return err
}
configChanges = configw.Changes()
// Restart the relations watcher.
if err := relationsw.Stop(); err != nil {
return err
}
relationsw, err = f.service.WatchRelations()
if err != nil {
return err
}
f.upgradeFrom.url = curl
if err = f.upgradeChanged(); err != nil {
return err
}
case force := <-f.wantForcedUpgrade:
filterLogger.Debugf("want forced upgrade %v", force)
f.upgradeFrom.force = force
if err = f.upgradeChanged(); err != nil {
return err
}
case <-f.wantResolved:
filterLogger.Debugf("want resolved event")
if f.resolved != params.ResolvedNone {
f.outResolved = f.outResolvedOn
}
case <-f.clearResolved:
filterLogger.Debugf("resolved event handled")
f.outResolved = nil
if err := f.unit.ClearResolved(); err != nil {
return err
}
if err := f.unitChanged(); err != nil {
return err
}
select {
case <-f.tomb.Dying():
return tomb.ErrDying
case f.didClearResolved <- nothing:
}
case <-discardConfig:
filterLogger.Debugf("discarded config event")
f.outConfig = nil
}
}
}
func (f *filter) loop(unitTag names.UnitTag) (err error) {
// TODO(dfc) named return value is a time bomb
defer func() {
if params.IsCodeNotFoundOrCodeUnauthorized(err) {
err = worker.ErrTerminateAgent
}
}()
if f.unit, err = f.st.Unit(unitTag); err != nil {
return err
}
if err = f.unitChanged(); err != nil {
return err
}
if err = f.meterStatusChanged(); err != nil {
return err
}
f.service, err = f.unit.Service()
if err != nil {
return err
}
if err = f.serviceChanged(); err != nil {
return err
}
unitw, err := f.unit.Watch()
if err != nil {
return err
}
defer f.maybeStopWatcher(unitw)
servicew, err := f.service.Watch()
if err != nil {
return err
}
defer f.maybeStopWatcher(servicew)
// configw and relationsw can get restarted, so we need to use
// their eventual values in the defer calls.
var configw apiwatcher.NotifyWatcher
var configChanges <-chan struct{}
curl, err := f.unit.CharmURL()
if err == nil {
configw, err = f.unit.WatchConfigSettings()
if err != nil {
return err
}
configChanges = configw.Changes()
f.upgradeFrom.url = curl
} else if err != uniter.ErrNoCharmURLSet {
filterLogger.Errorf("unit charm: %v", err)
return err
}
defer f.maybeStopWatcher(configw)
actionsw, err := f.unit.WatchActionNotifications()
if err != nil {
return err
}
f.actionsPending = make([]string, 0)
defer f.maybeStopWatcher(actionsw)
relationsw, err := f.service.WatchRelations()
if err != nil {
return err
}
defer f.maybeStopWatcher(relationsw)
meterStatusw, err := f.unit.WatchMeterStatus()
if err != nil {
return err
}
defer f.maybeStopWatcher(meterStatusw)
addressesw, err := f.unit.WatchAddresses()
if err != nil {
return err
}
defer watcher.Stop(addressesw, &f.tomb)
storagew, err := f.unit.WatchStorage()
if err != nil {
return err
}
defer watcher.Stop(storagew, &f.tomb)
leaderSettingsw, err := f.st.LeadershipSettings.WatchLeadershipSettings(f.service.Tag().Id())
if err != nil {
return err
}
defer watcher.Stop(leaderSettingsw, &f.tomb)
// Ignore external requests for leader settings behaviour until we see the first change.
var discardLeaderSettings <-chan struct{}
var wantLeaderSettings <-chan bool
// By default we send all leaderSettings onwards.
sendLeaderSettings := true
// Config events cannot be meaningfully discarded until one is available;
// once we receive the initial config and address changes, we unblock
// discard requests by setting this channel to its namesake on f.
var discardConfig chan struct{}
var seenConfigChange bool
var seenAddressChange bool
maybePrepareConfigEvent := func() {
if !seenAddressChange {
filterLogger.Debugf("no address change seen yet, skipping config event")
return
}
if !seenConfigChange {
filterLogger.Debugf("no config change seen yet, skipping config event")
return
}
filterLogger.Debugf("preparing new config event")
f.outConfig = f.outConfigOn
discardConfig = f.discardConfig
}
for {
var ok bool
select {
case <-f.tomb.Dying():
return tomb.ErrDying
// Handle watcher changes.
case _, ok = <-unitw.Changes():
filterLogger.Debugf("got unit change")
if !ok {
return watcher.EnsureErr(unitw)
}
if err = f.unitChanged(); err != nil {
return err
}
case _, ok = <-servicew.Changes():
filterLogger.Debugf("got service change")
if !ok {
return watcher.EnsureErr(servicew)
}
if err = f.serviceChanged(); err != nil {
return err
}
case _, ok = <-configChanges:
filterLogger.Debugf("got config change")
if !ok {
return watcher.EnsureErr(configw)
}
seenConfigChange = true
maybePrepareConfigEvent()
case _, ok = <-addressesw.Changes():
filterLogger.Debugf("got address change")
if !ok {
return watcher.EnsureErr(addressesw)
}
seenAddressChange = true
maybePrepareConfigEvent()
case _, ok = <-meterStatusw.Changes():
filterLogger.Debugf("got meter status change")
if !ok {
return watcher.EnsureErr(meterStatusw)
}
if err = f.meterStatusChanged(); err != nil {
return errors.Trace(err)
}
case ids, ok := <-actionsw.Changes():
filterLogger.Debugf("got %d actions", len(ids))
if !ok {
return watcher.EnsureErr(actionsw)
}
f.actionsPending = append(f.actionsPending, ids...)
f.nextAction = f.getNextAction()
case keys, ok := <-relationsw.Changes():
filterLogger.Debugf("got relations change")
if !ok {
return watcher.EnsureErr(relationsw)
}
var ids []int
for _, key := range keys {
relationTag := names.NewRelationTag(key)
rel, err := f.st.Relation(relationTag)
if params.IsCodeNotFoundOrCodeUnauthorized(err) {
// If it's actually gone, this unit cannot have entered
// scope, and therefore never needs to know about it.
} else if err != nil {
return err
} else {
ids = append(ids, rel.Id())
}
}
f.relationsChanged(ids)
case ids, ok := <-storagew.Changes():
filterLogger.Debugf("got storage change")
if !ok {
return watcher.EnsureErr(storagew)
}
tags := make([]names.StorageTag, len(ids))
for i, id := range ids {
tag := names.NewStorageTag(id)
tags[i] = tag
}
f.storageChanged(tags)
case _, ok = <-leaderSettingsw.Changes():
filterLogger.Debugf("got leader settings change: ok=%t", ok)
if !ok {
return watcher.EnsureErr(leaderSettingsw)
}
if sendLeaderSettings {
// only send the leader settings changed event
// if it hasn't been explicitly disabled
f.outLeaderSettings = f.outLeaderSettingsOn
} else {
filterLogger.Debugf("not sending leader settings change (want=false)")
}
discardLeaderSettings = f.discardLeaderSettings
wantLeaderSettings = f.wantLeaderSettings
// Send events on active out chans.
case f.outUpgrade <- f.upgrade:
filterLogger.Debugf("sent upgrade event")
f.outUpgrade = nil
case f.outResolved <- f.resolved:
filterLogger.Debugf("sent resolved event")
f.outResolved = nil
case f.outConfig <- nothing:
filterLogger.Debugf("sent config event")
f.outConfig = nil
case f.outLeaderSettings <- nothing:
filterLogger.Debugf("sent leader settings event")
f.outLeaderSettings = nil
case f.outAction <- f.nextAction:
f.nextAction = f.getNextAction()
filterLogger.Debugf("sent action event")
case f.outRelations <- f.relations:
filterLogger.Debugf("sent relations event")
f.outRelations = nil
f.relations = nil
case f.outMeterStatus <- nothing:
filterLogger.Debugf("sent meter status change event")
f.outMeterStatus = nil
case f.outStorage <- f.storage:
filterLogger.Debugf("sent storage event")
f.outStorage = nil
f.storage = nil
// Handle explicit requests.
case curl := <-f.setCharm:
filterLogger.Debugf("changing charm to %q", curl)
// We need to restart the config watcher after setting the
// charm, because service config settings are distinct for
// different service charms.
if configw != nil {
if err := configw.Stop(); err != nil {
return err
}
}
if err := f.unit.SetCharmURL(curl); err != nil {
filterLogger.Debugf("failed setting charm url %q: %v", curl, err)
return err
}
select {
case <-f.tomb.Dying():
return tomb.ErrDying
case f.didSetCharm <- nothing:
}
configw, err = f.unit.WatchConfigSettings()
if err != nil {
return err
}
configChanges = configw.Changes()
// Restart the relations watcher.
if err := relationsw.Stop(); err != nil {
return err
}
relationsw, err = f.service.WatchRelations()
if err != nil {
return err
}
f.upgradeFrom.url = curl
if err = f.upgradeChanged(); err != nil {
return err
}
case force := <-f.wantForcedUpgrade:
filterLogger.Debugf("want forced upgrade %v", force)
f.upgradeFrom.force = force
if err = f.upgradeChanged(); err != nil {
return err
}
case <-f.wantResolved:
filterLogger.Debugf("want resolved event")
if f.resolved != params.ResolvedNone {
f.outResolved = f.outResolvedOn
}
case sendEvents := <-wantLeaderSettings:
filterLogger.Debugf("want leader settings event: %t", sendEvents)
sendLeaderSettings = sendEvents
if sendEvents {
// go ahead and send an event right now,
// they're waiting for us
f.outLeaderSettings = f.outLeaderSettingsOn
} else {
// Make sure we don't have a pending event
f.outLeaderSettings = nil
}
case <-f.clearResolved:
filterLogger.Debugf("resolved event handled")
f.outResolved = nil
if err := f.unit.ClearResolved(); err != nil {
return err
}
if err := f.unitChanged(); err != nil {
return err
}
select {
case <-f.tomb.Dying():
return tomb.ErrDying
case f.didClearResolved <- nothing:
}
case <-discardConfig:
filterLogger.Debugf("discarded config event")
f.outConfig = nil
case <-discardLeaderSettings:
filterLogger.Debugf("discarded leader settings event")
f.outLeaderSettings = nil
}
}
}