// Update is part of the Relations interface.
func (r *relations) Update(ids []int) error {
for _, id := range ids {
if relationer, found := r.relationers[id]; found {
rel := relationer.ru.Relation()
if err := rel.Refresh(); err != nil {
return errors.Annotatef(err, "cannot update relation %q", rel)
}
if rel.Life() == params.Dying {
if err := r.setDying(id); err != nil {
return errors.Trace(err)
}
}
continue
}
// Relations that are not alive are simply skipped, because they
// were not previously known anyway.
rel, err := r.st.RelationById(id)
if err != nil {
if params.IsCodeNotFoundOrCodeUnauthorized(err) {
continue
}
return errors.Trace(err)
}
if rel.Life() != params.Alive {
continue
}
// Make sure we ignore relations not implemented by the unit's charm.
ch, err := corecharm.ReadCharmDir(r.charmDir)
if err != nil {
return errors.Trace(err)
}
if ep, err := rel.Endpoint(); err != nil {
return errors.Trace(err)
} else if !ep.ImplementedBy(ch) {
logger.Warningf("skipping relation with unknown endpoint %q", ep.Name)
continue
}
dir, err := relation.ReadStateDir(r.relationsDir, id)
if err != nil {
return errors.Trace(err)
}
err = r.add(rel, dir)
if err == nil {
r.relationers[id].StartHooks()
continue
}
e := dir.Remove()
if !params.IsCodeCannotEnterScope(err) {
return errors.Trace(err)
}
if e != nil {
return errors.Trace(e)
}
}
if ok, err := r.unit.IsPrincipal(); err != nil {
return errors.Trace(err)
} else if ok {
return nil
}
// If no Alive relations remain between a subordinate unit's service
// and its principal's service, the subordinate must become Dying.
for _, relationer := range r.relationers {
scope := relationer.ru.Endpoint().Scope
if scope == corecharm.ScopeContainer && !relationer.dying {
return nil
}
}
return r.unit.Destroy()
}
func (r *relations) update(remote map[int]remotestate.RelationSnapshot) error {
for id, relationSnapshot := range remote {
if _, found := r.relationers[id]; found {
// We've seen this relation before. The only changes
// we care about are to the lifecycle state, and to
// the member settings versions. We handle differences
// in settings in nextRelationHook.
if relationSnapshot.Life == params.Dying {
if err := r.setDying(id); err != nil {
return errors.Trace(err)
}
}
continue
}
// Relations that are not alive are simply skipped, because they
// were not previously known anyway.
if relationSnapshot.Life != params.Alive {
continue
}
rel, err := r.st.RelationById(id)
if err != nil {
if params.IsCodeNotFoundOrCodeUnauthorized(err) {
continue
}
return errors.Trace(err)
}
// Make sure we ignore relations not implemented by the unit's charm.
ch, err := corecharm.ReadCharmDir(r.charmDir)
if err != nil {
return errors.Trace(err)
}
if ep, err := rel.Endpoint(); err != nil {
return errors.Trace(err)
} else if !ep.ImplementedBy(ch) {
logger.Warningf("skipping relation with unknown endpoint %q", ep.Name)
continue
}
dir, err := ReadStateDir(r.relationsDir, id)
if err != nil {
return errors.Trace(err)
}
addErr := r.add(rel, dir)
if addErr == nil {
continue
}
removeErr := dir.Remove()
if !params.IsCodeCannotEnterScope(addErr) {
return errors.Trace(addErr)
}
if removeErr != nil {
return errors.Trace(removeErr)
}
}
if ok, err := r.unit.IsPrincipal(); err != nil {
return errors.Trace(err)
} else if ok {
return nil
}
// If no Alive relations remain between a subordinate unit's service
// and its principal's service, the subordinate must become Dying.
for _, relationer := range r.relationers {
scope := relationer.ru.Endpoint().Scope
if scope == corecharm.ScopeContainer && !relationer.dying {
return nil
}
}
return r.unit.Destroy()
}
// updateRelations responds to changes in the life states of the relations
// with the supplied ids. If any id corresponds to an alive relation not
// known to the unit, the uniter will join that relation and return its
// relationer in the added list.
func (u *Uniter) updateRelations(ids []int) (added []*Relationer, err error) {
for _, id := range ids {
if r, found := u.relationers[id]; found {
rel := r.ru.Relation()
if err := rel.Refresh(); err != nil {
return nil, fmt.Errorf("cannot update relation %q: %v", rel, err)
}
if rel.Life() == params.Dying {
if err := r.SetDying(); err != nil {
return nil, err
} else if r.IsImplicit() {
delete(u.relationers, id)
}
}
continue
}
// Relations that are not alive are simply skipped, because they
// were not previously known anyway.
rel, err := u.st.RelationById(id)
if err != nil {
if params.IsCodeNotFoundOrCodeUnauthorized(err) {
continue
}
return nil, err
}
if rel.Life() != params.Alive {
continue
}
// Make sure we ignore relations not implemented by the unit's charm.
ch, err := corecharm.ReadCharmDir(u.charmPath)
if err != nil {
return nil, err
}
if ep, err := rel.Endpoint(); err != nil {
return nil, err
} else if !ep.ImplementedBy(ch) {
logger.Warningf("skipping relation with unknown endpoint %q", ep.Name)
continue
}
dir, err := relation.ReadStateDir(u.relationsDir, id)
if err != nil {
return nil, err
}
err = u.addRelation(rel, dir)
if err == nil {
added = append(added, u.relationers[id])
continue
}
e := dir.Remove()
if !params.IsCodeCannotEnterScope(err) {
return nil, err
}
if e != nil {
return nil, e
}
}
if ok, err := u.unit.IsPrincipal(); err != nil {
return nil, err
} else if ok {
return added, nil
}
// If no Alive relations remain between a subordinate unit's service
// and its principal's service, the subordinate must become Dying.
keepAlive := false
for _, r := range u.relationers {
scope := r.ru.Endpoint().Scope
if scope == corecharm.ScopeContainer && !r.dying {
keepAlive = true
break
}
}
if !keepAlive {
if err := u.unit.Destroy(); err != nil {
return nil, err
}
}
return added, nil
}