Add base setup

manager.go

@@ -0,0 +1,121 @@
+package curre
+
+import (
+	"context"
+	"sync"
+)
+
+const (
+	OK       = 0
+	Internal = 1
+)
+
+type Manager struct {
+	components    []Component
+	logger        Logger
+	startStopLock sync.Mutex
+	started       bool
+	exitChan      chan int
+	exitCode      int
+	lifetime      Lifetime
+}
+
+func NewManager() *Manager {
+	return &Manager{
+		logger: &DefaultLogger{}, exitChan: make(chan int, 1),
+		exitCode: OK,
+	}
+}
+
+func (m *Manager) Register(components ...Component) *Manager {
+	if m.started {
+		panic("cannot register to a started manager")
+	}
+
+	m.components = append(m.components, components...)
+
+	return m
+}
+
+func (m *Manager) Init(ctx context.Context) error {
+	if m.started {
+		panic("cannot reinit a started manager")
+	}
+
+	for _, c := range m.components {
+		err := c.Init(ctx)
+		if err != nil {
+			return err
+		}
+
+		m.logger.Info("Manager: Init: %T", c)
+	}
+
+	return nil
+}
+
+func (m *Manager) Start(ctx context.Context) error {
+	for _, c := range m.components {
+		go m.startComponent(ctx, c)
+	}
+
+	return nil
+}
+
+func (m *Manager) startComponent(ctx context.Context, component Component) {
+	defer func() {
+		err := recover()
+		if err != nil {
+			m.logger.Error("Panic occurred in component: %T, error: %s", component, err)
+		}
+
+		m.exitChan <- Internal
+	}()
+
+	m.logger.Info("Starting %T", component)
+	err := component.Start(ctx)
+	if err != nil {
+		m.logger.Error("Component: %T encountered an error: ", component, err)
+		m.exitChan <- Internal
+		return
+	}
+
+	m.logger.Info("Component %T, done running", component)
+
+}
+
+func (m *Manager) initLifetime() {
+	go func() {
+		exitCode := m.lifetime()
+		m.logger.Info("Exit signal received: %d", exitCode)
+		m.exitChan <- exitCode
+	}()
+}
+
+func (m *Manager) Wait(ctx context.Context) error {
+	exitCode := <-m.exitChan
+	m.exitCode = exitCode
+	return nil
+}
+
+func (m *Manager) Shutdown(ctx context.Context) error {
+	shutdownChan := make(chan struct{}, 1)
+	closers := m.getClosers(ctx)
+
+	go func(ctx context.Context) {
+		for _, c := range closers {
+			c.Close(ctx)
+		}
+
+		shutdownChan <- struct{}{}
+	}(ctx)
+
+	<-shutdownChan
+	m.logger.Info("Shutting down of components complete")
+
+	return nil
+}
+
+func (m *Manager) getClosers(ctx context.Context) []Component {
+	return m.components
+}