// This custom unmarshaller is needed because the json sent to us as a string
// rather than a fully typed object. We support both formats in the hopes that
// one day everything will be fully typed
// Note: the `json:",string"` tag DOES NOT apply here; it DOES NOT work with
// struct types, only ints/floats/etc. We're basically doing that though
// We also intentionally fail if there are any keys we were unable to unmarshal
// into our struct
func (overrides *ContainerOverrides) UnmarshalJSON(b []byte) error {
regular := ContainerOverridesCopy{}
// Try to do it the strongly typed way first
err := json.Unmarshal(b, ®ular)
if err == nil {
err = utils.CompleteJsonUnmarshal(b, regular)
if err == nil {
*overrides = ContainerOverrides(regular)
return nil
}
err = utils.NewMultiError(errors.New("Error unmarshalling ContainerOverrides"), err)
}
// Now the stringly typed way
var str string
err2 := json.Unmarshal(b, &str)
if err2 != nil {
return utils.NewMultiError(errors.New("Could not unmarshal ContainerOverrides into either an object or string respectively"), err, err2)
}
// We have a string, let's try to unmarshal that into a typed object
err3 := json.Unmarshal([]byte(str), ®ular)
if err3 == nil {
err3 = utils.CompleteJsonUnmarshal([]byte(str), regular)
if err3 == nil {
*overrides = ContainerOverrides(regular)
return nil
} else {
err3 = utils.NewMultiError(errors.New("Error unmarshalling ContainerOverrides"), err3)
}
}
return utils.NewMultiError(errors.New("Could not unmarshal ContainerOverrides in any supported way"), err, err2, err3)
}
// FinalSave should be called immediately before exiting, and only before
// exiting, in order to flush tasks to disk. It waits a short timeout for state
// to settle if necessary. If unable to reach a steady-state and save within
// this short timeout, it returns an error
func FinalSave(saver statemanager.Saver, taskEngine engine.TaskEngine) error {
engineDisabled := make(chan error)
disableTimer := time.AfterFunc(engineDisableTimeout, func() {
engineDisabled <- errors.New("Timed out waiting for TaskEngine to settle")
})
go func() {
log.Debug("Shutting down task engine")
taskEngine.Disable()
disableTimer.Stop()
engineDisabled <- nil
}()
disableErr := <-engineDisabled
stateSaved := make(chan error)
saveTimer := time.AfterFunc(finalSaveTimeout, func() {
stateSaved <- errors.New("Timed out trying to save to disk")
})
go func() {
log.Debug("Saving state before shutting down")
stateSaved <- saver.ForceSave()
saveTimer.Stop()
}()
saveErr := <-stateSaved
if disableErr != nil || saveErr != nil {
return utils.NewMultiError(disableErr, saveErr)
}
return nil
}