Golang State.IsStateServer方法代碼示例

// EnsureAvailabilitySingle applies a single StateServersSpec specification to the current environment.
// Exported so it can be called by the legacy client API in the client package.
func EnsureAvailabilitySingle(st *state.State, spec params.StateServersSpec) (params.StateServersChanges, error) {
	if !st.IsStateServer() {
		return params.StateServersChanges{}, errors.New("unsupported with hosted environments")
	}
	// Check if changes are allowed and the command may proceed.
	blockChecker := common.NewBlockChecker(st)
	if err := blockChecker.ChangeAllowed(); err != nil {
		return params.StateServersChanges{}, errors.Trace(err)
	}
	// Validate the environment tag if present.
	if spec.EnvironTag != "" {
		tag, err := names.ParseEnvironTag(spec.EnvironTag)
		if err != nil {
			return params.StateServersChanges{}, errors.Errorf("invalid environment tag: %v", err)
		}
		if _, err := st.FindEntity(tag); err != nil {
			return params.StateServersChanges{}, err
		}
	}

	series := spec.Series
	if series == "" {
		ssi, err := st.StateServerInfo()
		if err != nil {
			return params.StateServersChanges{}, err
		}

		// We should always have at least one voting machine
		// If we *really* wanted we could just pick whatever series is
		// in the majority, but really, if we always copy the value of
		// the first one, then they'll stay in sync.
		if len(ssi.VotingMachineIds) == 0 {
			// Better than a panic()?
			return params.StateServersChanges{}, fmt.Errorf("internal error, failed to find any voting machines")
		}
		templateMachine, err := st.Machine(ssi.VotingMachineIds[0])
		if err != nil {
			return params.StateServersChanges{}, err
		}
		series = templateMachine.Series()
	}
	changes, err := st.EnsureAvailability(spec.NumStateServers, spec.Constraints, series, spec.Placement)
	if err != nil {
		return params.StateServersChanges{}, err
	}
	return stateServersChanges(changes), nil
}

// NewAPI creates a new instance of the Backups API facade.
func NewAPI(st *state.State, resources *common.Resources, authorizer common.Authorizer) (*API, error) {
	if !authorizer.AuthClient() {
		return nil, errors.Trace(common.ErrPerm)
	}

	// For now, backup operations are only permitted on the controller environment.
	if !st.IsStateServer() {
		return nil, errors.New("backups are not supported for hosted environments")
	}

	// Get the backup paths.
	dataDir, err := extractResourceValue(resources, "dataDir")
	if err != nil {
		return nil, errors.Trace(err)
	}
	logsDir, err := extractResourceValue(resources, "logDir")
	if err != nil {
		return nil, errors.Trace(err)
	}
	paths := backups.Paths{
		DataDir: dataDir,
		LogsDir: logsDir,
	}

	// Build the API.
	machineID, err := extractResourceValue(resources, "machineID")
	if err != nil {
		return nil, errors.Trace(err)
	}
	b := API{
		st:        st,
		paths:     &paths,
		machineID: machineID,
	}
	return &b, nil
}