package http import ( "context" "fmt" "hash/fnv" "io/ioutil" "net/http" "time" "github.com/cenkalti/backoff/v4" "github.com/containous/traefik/v2/pkg/config/dynamic" "github.com/containous/traefik/v2/pkg/config/file" "github.com/containous/traefik/v2/pkg/job" "github.com/containous/traefik/v2/pkg/log" "github.com/containous/traefik/v2/pkg/provider" "github.com/containous/traefik/v2/pkg/safe" "github.com/containous/traefik/v2/pkg/tls" "github.com/containous/traefik/v2/pkg/types" ) var _ provider.Provider = (*Provider)(nil) // Provider is a provider.Provider implementation that queries an HTTP(s) endpoint for a configuration. type Provider struct { Endpoint string `description:"Load configuration from this endpoint." json:"endpoint" toml:"endpoint" yaml:"endpoint" export:"true"` PollInterval types.Duration `description:"Polling interval for endpoint." json:"pollInterval,omitempty" toml:"pollInterval,omitempty" yaml:"pollInterval,omitempty"` PollTimeout types.Duration `description:"Polling timeout for endpoint." json:"pollTimeout,omitempty" toml:"pollTimeout,omitempty" yaml:"pollTimeout,omitempty"` TLS *types.ClientTLS `description:"Enable TLS support." json:"tls,omitempty" toml:"tls,omitempty" yaml:"tls,omitempty" export:"true"` httpClient *http.Client lastConfigurationHash uint64 } // SetDefaults sets the default values. func (p *Provider) SetDefaults() { p.PollInterval = types.Duration(5 * time.Second) p.PollTimeout = types.Duration(5 * time.Second) } // Init the provider. func (p *Provider) Init() error { if p.Endpoint == "" { return fmt.Errorf("non-empty endpoint is required") } if p.PollInterval <= 0 { return fmt.Errorf("poll interval must be greater than 0") } p.httpClient = &http.Client{ Timeout: time.Duration(p.PollTimeout), } if p.TLS != nil { tlsConfig, err := p.TLS.CreateTLSConfig(context.Background()) if err != nil { return fmt.Errorf("unable to create TLS configuration: %w", err) } p.httpClient.Transport = &http.Transport{ TLSClientConfig: tlsConfig, } } return nil } // Provide allows the provider to provide configurations to traefik using the given configuration channel. func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.Pool) error { pool.GoCtx(func(routineCtx context.Context) { ctxLog := log.With(routineCtx, log.Str(log.ProviderName, "http")) logger := log.FromContext(ctxLog) operation := func() error { ticker := time.NewTicker(time.Duration(p.PollInterval)) defer ticker.Stop() for { select { case <-ticker.C: configData, err := p.fetchConfigurationData() if err != nil { return fmt.Errorf("cannot fetch configuration data: %w", err) } fnvHasher := fnv.New64() _, err = fnvHasher.Write(configData) if err != nil { return fmt.Errorf("cannot hash configuration data: %w", err) } hash := fnvHasher.Sum64() if hash == p.lastConfigurationHash { continue } p.lastConfigurationHash = hash configuration, err := decodeConfiguration(configData) if err != nil { return fmt.Errorf("cannot decode configuration data: %w", err) } configurationChan <- dynamic.Message{ ProviderName: "http", Configuration: configuration, } case <-routineCtx.Done(): return nil } } } notify := func(err error, time time.Duration) { logger.Errorf("Provider connection error %+v, retrying in %s", err, time) } err := backoff.RetryNotify(safe.OperationWithRecover(operation), backoff.WithContext(job.NewBackOff(backoff.NewExponentialBackOff()), ctxLog), notify) if err != nil { logger.Errorf("Cannot connect to server endpoint %+v", err) } }) return nil } // fetchConfigurationData fetches the configuration data from the configured endpoint. func (p *Provider) fetchConfigurationData() ([]byte, error) { res, err := p.httpClient.Get(p.Endpoint) if err != nil { return nil, err } defer res.Body.Close() if res.StatusCode != http.StatusOK { return nil, fmt.Errorf("received non-ok response code: %d", res.StatusCode) } return ioutil.ReadAll(res.Body) } // decodeConfiguration decodes and returns the dynamic configuration from the given data. func decodeConfiguration(data []byte) (*dynamic.Configuration, error) { configuration := &dynamic.Configuration{ HTTP: &dynamic.HTTPConfiguration{ Routers: make(map[string]*dynamic.Router), Middlewares: make(map[string]*dynamic.Middleware), Services: make(map[string]*dynamic.Service), }, TCP: &dynamic.TCPConfiguration{ Routers: make(map[string]*dynamic.TCPRouter), Services: make(map[string]*dynamic.TCPService), }, TLS: &dynamic.TLSConfiguration{ Stores: make(map[string]tls.Store), Options: make(map[string]tls.Options), }, UDP: &dynamic.UDPConfiguration{ Routers: make(map[string]*dynamic.UDPRouter), Services: make(map[string]*dynamic.UDPService), }, } err := file.DecodeContent(string(data), ".yaml", configuration) if err != nil { return nil, err } return configuration, nil }