// DEPRECATED: use one of the Create* functions instead
func (s consulStore) Put(u roll_fields.Update) error {
b, err := json.Marshal(u)
if err != nil {
return err
}
key, err := RollPath(u.ID())
if err != nil {
return err
}
success, _, err := s.kv.CAS(&api.KVPair{
Key: key,
Value: b,
// it must not already exist
ModifyIndex: 0,
}, nil)
if err != nil {
return consulutil.NewKVError("cas", key, err)
}
if !success {
return fmt.Errorf("update with new RC ID %s already exists", u.NewRC)
}
return nil
}
// Attempts to create a rolling update. Checks sessionErrCh for session renewal
// errors just before actually doing the creation to minimize the likelihood of
// race conditions resulting in conflicting RUs
func (s consulStore) attemptRUCreation(u roll_fields.Update, rollLabels klabels.Set, sessionErrCh chan error) (createdRU roll_fields.Update, err error) {
// If we create an RU, we also want to create its labels. If the second step
// fails, we want to best-effort remove the RU
var ruCleanup func()
defer func() {
if err != nil && ruCleanup != nil {
ruCleanup()
}
}()
b, err := json.Marshal(u)
if err != nil {
return u, err
}
key, err := RollPath(roll_fields.ID(u.NewRC))
if err != nil {
return u, err
}
// Confirm that our lock session is still valid, and then create the
// rolling update. If session isn't valid, delete the newRC we just
// created
select {
case err := <-sessionErrCh:
if err == nil {
err = util.Errorf("Cannot create ru because session was destroyed")
}
return u, err
default:
success, _, err := s.kv.CAS(&api.KVPair{
Key: key,
Value: b,
}, nil)
if err != nil {
return u, consulutil.NewKVError("cas", key, err)
}
// Shouldn't be possible if our session is still valid, preventing other insertions
if !success {
return u, util.Errorf("update with new RC ID %s already exists", u.NewRC)
}
ruCleanup = func() {
err := s.Delete(u.ID())
if err != nil {
s.logger.WithError(err).Errorln("Unable to cleanup RU %s after failed labeling attempt", u.ID())
}
}
}
err = s.labeler.SetLabels(labels.RU, u.ID().String(), rollLabels)
if err != nil {
return roll_fields.Update{}, err
}
return u, nil
}
func TestCreateRollingUpdateFromExistingRCs(t *testing.T) {
rollstore := newRollStore(t, nil)
newRCID := rc_fields.ID("new_rc")
oldRCID := rc_fields.ID("old_rc")
update := fields.Update{
NewRC: newRCID,
OldRC: oldRCID,
}
newRCLabels := klabels.Set(map[string]string{
"some_key": "some_val",
})
u, err := rollstore.CreateRollingUpdateFromExistingRCs(update, newRCLabels, newRCLabels)
if err != nil {
t.Fatalf("Unexpected error creating update: %s", err)
}
storedUpdate, err := rollstore.Get(update.ID())
if err != nil {
t.Fatalf("Unable to retrieve value put in roll store: %s", err)
}
if storedUpdate.NewRC != newRCID {
t.Errorf("Stored update didn't have expected new rc value: wanted '%s' but got '%s'", newRCID, storedUpdate.NewRC)
}
if storedUpdate.OldRC != oldRCID {
t.Errorf("Stored update didn't have expected old rc value: wanted '%s' but got '%s'", oldRCID, storedUpdate.OldRC)
}
rcLabels, err := rollstore.labeler.GetLabels(labels.RC, newRCID.String())
if err != nil {
t.Fatalf("Unable to fetch labels for newly created new RC: %s", err)
}
if rcLabels.Labels["some_key"] != "some_val" {
t.Errorf("Expected labels to be set on new RC")
}
ruLabels, err := rollstore.labeler.GetLabels(labels.RU, u.ID().String())
if err != nil {
t.Fatalf("Unable to fetch labels for newly created new RU: %s", err)
}
if ruLabels.Labels["some_key"] != "some_val" {
t.Errorf("Expected labels to be set on new RU")
}
}
// Validates that the rolling update is capable of being processed. If not, an
// error is returned.
// The following conditions make an RU invalid:
// 1) New RC does not exist
// 2) Old RC does not exist
func (rlf *Farm) validateRoll(update roll_fields.Update, logger logging.Logger) error {
_, err := rlf.rcs.Get(update.NewRC)
if err == rcstore.NoReplicationController {
return fmt.Errorf("RU '%s' is invalid, new RC '%s' did not exist", update.ID(), update.NewRC)
} else if err != nil {
// There was a potentially transient consul error, we don't necessarily want to delete the RU
logger.WithError(err).Errorln("Could not fetch new RC to validate RU, assuming it's valid")
}
_, err = rlf.rcs.Get(update.OldRC)
if err == rcstore.NoReplicationController {
return fmt.Errorf("RU '%s' is invalid, old RC '%s' did not exist", update.ID(), update.OldRC)
} else if err != nil {
// There was a potentially transient consul error, we don't necessarily want to delete the RU
logger.WithError(err).Errorln("Could not fetch old RC in order to validate RU, assuming it's valid")
}
return nil
}
// Test that if a conflicting update exists, a new one will not be admitted
func TestCreateExistingRCsMutualExclusion(t *testing.T) {
newRCID := rc_fields.ID("new_rc")
oldRCID := rc_fields.ID("old_rc")
conflictingEntry := fields.Update{
OldRC: newRCID,
NewRC: rc_fields.ID("some_other_rc"),
}
rollstore := newRollStore(t, []fields.Update{conflictingEntry})
update := fields.Update{
NewRC: newRCID,
OldRC: oldRCID,
}
_, err := rollstore.CreateRollingUpdateFromExistingRCs(update, nil, nil)
if err == nil {
t.Fatal("Expected update creation to fail due to conflict")
}
if conflictingErr, ok := err.(*ConflictingRUError); !ok {
t.Error("Returned error didn't have ConflictingRUError type")
} else {
if conflictingErr.ConflictingID != conflictingEntry.ID() {
t.Errorf("Expected error to have conflicting ID of '%s', was '%s'", conflictingEntry.ID(), conflictingErr.ConflictingID)
}
if conflictingErr.ConflictingRCID != conflictingEntry.OldRC {
t.Errorf("Expected error to have conflicting rc ID of '%s', was '%s'", conflictingEntry.OldRC, conflictingErr.ConflictingRCID)
}
}
ru, _ := rollstore.Get(fields.ID(update.NewRC))
if ru.NewRC != "" || ru.OldRC != "" {
t.Fatal("New ru shouldn't have been created but it was")
}
}