Added Init state. Recreate exit and advertise channels when recovering
In order to differentiate between intialized and other states we introduced a new state: Init. The router is in this state only when it's created. We have cleaned up router status management which is now handled by manageStatus function only.
This commit is contained in:
Milos Gajdos
parent
32300eadc1
commit
cff46c3fd8
@ -32,7 +32,7 @@ func newRouter(opts ...Option) Router {
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return &router{
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opts: options,
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status: Status{Error: nil, Code: Stopped},
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status: Status{Error: nil, Code: Init},
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advertChan: make(chan *Update),
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exit: make(chan struct{}),
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wg: &sync.WaitGroup{},
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@ -72,99 +72,6 @@ func (r *router) Network() string {
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return r.opts.Network
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}
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// Advertise advertises the routes to the network.
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// It returns error if any of the launched goroutines fail with error.
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func (r *router) Advertise() (<-chan *Update, error) {
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r.Lock()
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defer r.Unlock()
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if r.status.Code != Running {
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// add local service routes into the routing table
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if err := r.addServiceRoutes(r.opts.Registry, "local", DefaultLocalMetric); err != nil {
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return nil, fmt.Errorf("failed adding routes: %v", err)
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}
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// add default gateway into routing table
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if r.opts.Gateway != "" {
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// note, the only non-default value is the gateway
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route := Route{
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Destination: "*",
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Gateway: r.opts.Gateway,
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Router: "*",
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Network: "*",
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Metric: DefaultLocalMetric,
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}
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if err := r.opts.Table.Add(route); err != nil {
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return nil, fmt.Errorf("error to add default gateway route: %s", err)
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}
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}
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// routing table watcher which watches all routes i.e. to every destination
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tableWatcher, err := r.opts.Table.Watch(WatchDestination("*"))
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if err != nil {
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return nil, fmt.Errorf("failed to create routing table watcher: %v", err)
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}
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// registry watcher
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regWatcher, err := r.opts.Registry.Watch()
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if err != nil {
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return nil, fmt.Errorf("failed to create registry watcher: %v", err)
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}
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// error channel collecting goroutine errors
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errChan := make(chan error, 2)
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r.wg.Add(1)
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go func() {
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defer r.wg.Done()
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// watch local registry and register routes in routine table
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errChan <- r.manageServiceRoutes(regWatcher, DefaultLocalMetric)
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}()
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r.wg.Add(1)
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go func() {
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defer r.wg.Done()
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// watch local registry and register routes in routing table
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errChan <- r.watchTable(tableWatcher)
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}()
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r.wg.Add(1)
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go func() {
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defer r.wg.Done()
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select {
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// wait for exit chan
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case <-r.exit:
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r.status.Code = Stopped
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case err := <-errChan:
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r.status.Code = Error
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r.status.Error = err
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}
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// close the advertise channel
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close(r.advertChan)
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}()
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// mark the router as running
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r.status.Code = Running
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}
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return r.advertChan, nil
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}
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// Update updates the routing table using the advertised values
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func (r *router) Update(a *Update) error {
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// we extract the route from advertisement and update the routing table
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route := Route{
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Destination: a.Event.Route.Destination,
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Gateway: a.Event.Route.Gateway,
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Router: a.Event.Route.Router,
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Network: a.Event.Route.Network,
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Metric: a.Event.Route.Metric,
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Policy: AddIfNotExists,
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}
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return r.opts.Table.Update(route)
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}
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// addServiceRoutes adds all services in given registry to the routing table.
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// NOTE: this is a one-off operation done when bootstrapping the routing table
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// It returns error if either the services failed to be listed or
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@ -301,21 +208,145 @@ func (r *router) watchTable(w Watcher) error {
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return watchErr
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}
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// manageStatus manages router status
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func (r *router) manageStatus(errChan <-chan error) {
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defer r.wg.Done()
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r.Lock()
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r.status.Code = Running
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r.status.Error = nil
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r.Unlock()
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var code StatusCode
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var err error
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select {
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case <-r.exit:
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code = Stopped
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case err = <-errChan:
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code = Error
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}
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r.Lock()
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defer r.Unlock()
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r.status.Code = code
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r.status.Error = err
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// close the advertise channel
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close(r.advertChan)
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// stop the router if some error happened
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// this will notify all watcher goroutines to stop
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if err != nil && code != Stopped {
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close(r.exit)
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}
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}
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// Advertise advertises the routes to the network.
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// It returns error if any of the launched goroutines fail with error.
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func (r *router) Advertise() (<-chan *Update, error) {
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r.Lock()
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defer r.Unlock()
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if r.status.Code != Running {
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// add local service routes into the routing table
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if err := r.addServiceRoutes(r.opts.Registry, "local", DefaultLocalMetric); err != nil {
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return nil, fmt.Errorf("failed adding routes: %v", err)
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}
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// add default gateway into routing table
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if r.opts.Gateway != "" {
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// note, the only non-default value is the gateway
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route := Route{
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Destination: "*",
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Gateway: r.opts.Gateway,
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Router: "*",
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Network: "*",
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Metric: DefaultLocalMetric,
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}
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if err := r.opts.Table.Add(route); err != nil {
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return nil, fmt.Errorf("error to add default gateway route: %s", err)
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}
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}
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// NOTE: we only need to recreate the exit/advertChan if the router errored or was stopped
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if r.status.Code == Error || r.status.Code == Stopped {
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r.exit = make(chan struct{})
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r.advertChan = make(chan *Update)
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}
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// routing table watcher which watches all routes i.e. to every destination
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tableWatcher, err := r.opts.Table.Watch(WatchDestination("*"))
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if err != nil {
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return nil, fmt.Errorf("failed to create routing table watcher: %v", err)
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}
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// registry watcher
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regWatcher, err := r.opts.Registry.Watch()
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if err != nil {
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return nil, fmt.Errorf("failed to create registry watcher: %v", err)
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}
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// error channel collecting goroutine errors
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errChan := make(chan error, 2)
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r.wg.Add(1)
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go func() {
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defer r.wg.Done()
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// watch local registry and register routes in routine table
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errChan <- r.manageServiceRoutes(regWatcher, DefaultLocalMetric)
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}()
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r.wg.Add(1)
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go func() {
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defer r.wg.Done()
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// watch local registry and register routes in routing table
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errChan <- r.watchTable(tableWatcher)
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}()
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r.wg.Add(1)
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go r.manageStatus(errChan)
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}
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return r.advertChan, nil
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}
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// Update updates the routing table using the advertised values
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func (r *router) Update(a *Update) error {
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// we extract the route from advertisement and update the routing table
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route := Route{
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Destination: a.Event.Route.Destination,
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Gateway: a.Event.Route.Gateway,
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Router: a.Event.Route.Router,
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Network: a.Event.Route.Network,
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Metric: a.Event.Route.Metric,
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Policy: AddIfNotExists,
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}
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return r.opts.Table.Update(route)
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}
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// Status returns router status
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func (r *router) Status() Status {
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r.RLock()
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defer r.RUnlock()
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return r.status
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// make a copy of the status
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status := r.status
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return status
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}
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// Stop stops the router
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func (r *router) Stop() error {
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// notify all goroutines to finish
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close(r.exit)
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r.RLock()
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defer r.RUnlock()
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// wait for all goroutines to finish
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r.wg.Wait()
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// only close the channel if the router is running
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if r.status.Code == Running {
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// notify all goroutines to finish
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close(r.exit)
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// wait for all goroutines to finish
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r.wg.Wait()
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}
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return nil
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}
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@ -325,13 +356,14 @@ func (r *router) String() string {
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sb := &strings.Builder{}
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table := tablewriter.NewWriter(sb)
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table.SetHeader([]string{"ID", "Address", "Network", "Table"})
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table.SetHeader([]string{"ID", "Address", "Network", "Table", "Status"})
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data := []string{
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r.opts.ID,
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r.opts.Address,
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r.opts.Network,
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fmt.Sprintf("%d", r.opts.Table.Size()),
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r.status.Code.String(),
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}
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table.Append(data)
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@ -56,8 +56,10 @@ type Status struct {
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}
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const (
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// Running means the rotuer is running
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Running StatusCode = iota
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// Init means the rotuer has just been initialized
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Init StatusCode = iota
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// Running means the router is running
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Running
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// Error means the router has crashed with error
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Error
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// Stopped means the router has stopped
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@ -67,6 +69,8 @@ const (
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// String returns human readable status code
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func (sc StatusCode) String() string {
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switch sc {
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case Init:
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return "INITIALIZED"
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case Running:
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return "RUNNING"
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case Error:
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