package hub import ( "crypto/tls" "crypto/x509" "errors" "fmt" "net" "net/http" "github.com/rs/zerolog/log" "github.com/traefik/traefik/v2/pkg/config/dynamic" "github.com/traefik/traefik/v2/pkg/logs" "github.com/traefik/traefik/v2/pkg/provider" "github.com/traefik/traefik/v2/pkg/safe" ttls "github.com/traefik/traefik/v2/pkg/tls" ) var _ provider.Provider = (*Provider)(nil) // Entrypoints created for Hub. const ( APIEntrypoint = "traefikhub-api" TunnelEntrypoint = "traefikhub-tunl" ) // Provider holds configurations of the provider. type Provider struct { TLS *TLS `description:"TLS configuration for mTLS communication between Traefik and Hub Agent." json:"tls,omitempty" toml:"tls,omitempty" yaml:"tls,omitempty" export:"true"` server *http.Server } // TLS configures the mTLS connection between Traefik Proxy and the Traefik Hub Agent. type TLS struct { Insecure bool `description:"Enables an insecure TLS connection that uses default credentials, and which has no peer authentication between Traefik Proxy and the Traefik Hub Agent." json:"insecure,omitempty" toml:"insecure,omitempty" yaml:"insecure,omitempty" export:"true"` CA ttls.FileOrContent `description:"The certificate authority authenticates the Traefik Hub Agent certificate." json:"ca,omitempty" toml:"ca,omitempty" yaml:"ca,omitempty" loggable:"false"` Cert ttls.FileOrContent `description:"The TLS certificate for Traefik Proxy as a TLS client." json:"cert,omitempty" toml:"cert,omitempty" yaml:"cert,omitempty" loggable:"false"` Key ttls.FileOrContent `description:"The TLS key for Traefik Proxy as a TLS client." json:"key,omitempty" toml:"key,omitempty" yaml:"key,omitempty" loggable:"false"` } // Init the provider. func (p *Provider) Init() error { return nil } // Provide allows the hub provider to provide configurations to traefik using the given configuration channel. func (p *Provider) Provide(configurationChan chan<- dynamic.Message, _ *safe.Pool) error { if p.TLS == nil { return nil } listener, err := net.Listen("tcp", "127.0.0.1:0") if err != nil { return fmt.Errorf("listener: %w", err) } port := listener.Addr().(*net.TCPAddr).Port client, err := createAgentClient(p.TLS) if err != nil { return fmt.Errorf("creating Hub Agent HTTP client: %w", err) } p.server = &http.Server{Handler: newHandler(APIEntrypoint, port, configurationChan, p.TLS, client)} // TODO: this is going to be leaky (because no context to make it terminate) // if/when Provide lifecycle differs with Traefik lifecycle. go func() { if err = p.server.Serve(listener); err != nil { log.Error().Str(logs.ProviderName, "hub").Err(err).Msg("Unexpected error while running server") return } }() exposeAPIAndMetrics(configurationChan, APIEntrypoint, port, p.TLS) return nil } func exposeAPIAndMetrics(cfgChan chan<- dynamic.Message, ep string, port int, tlsCfg *TLS) { cfg := emptyDynamicConfiguration() patchDynamicConfiguration(cfg, ep, port, tlsCfg) cfgChan <- dynamic.Message{ProviderName: "hub", Configuration: cfg} } func patchDynamicConfiguration(cfg *dynamic.Configuration, ep string, port int, tlsCfg *TLS) { cfg.HTTP.Routers["traefik-hub-agent-api"] = &dynamic.Router{ EntryPoints: []string{ep}, Service: "api@internal", Rule: "Host(`proxy.traefik`) && PathPrefix(`/api`)", } cfg.HTTP.Routers["traefik-hub-agent-metrics"] = &dynamic.Router{ EntryPoints: []string{ep}, Service: "prometheus@internal", Rule: "Host(`proxy.traefik`) && PathPrefix(`/metrics`)", } cfg.HTTP.Routers["traefik-hub-agent-service"] = &dynamic.Router{ EntryPoints: []string{ep}, Service: "traefik-hub-agent-service", Rule: "Host(`proxy.traefik`) && (PathPrefix(`/config`) || PathPrefix(`/discover-ip`) || PathPrefix(`/state`))", } cfg.HTTP.Services["traefik-hub-agent-service"] = &dynamic.Service{ LoadBalancer: &dynamic.ServersLoadBalancer{ Servers: []dynamic.Server{ { URL: fmt.Sprintf("http://127.0.0.1:%d", port), }, }, }, } if tlsCfg == nil { return } if tlsCfg.Insecure { cfg.TLS.Options["traefik-hub"] = ttls.Options{ MinVersion: "VersionTLS13", } return } cfg.TLS.Options["traefik-hub"] = ttls.Options{ ClientAuth: ttls.ClientAuth{ CAFiles: []ttls.FileOrContent{tlsCfg.CA}, ClientAuthType: "RequireAndVerifyClientCert", }, SniStrict: true, MinVersion: "VersionTLS13", } cfg.TLS.Certificates = append(cfg.TLS.Certificates, &ttls.CertAndStores{ Certificate: ttls.Certificate{ CertFile: tlsCfg.Cert, KeyFile: tlsCfg.Key, }, }) } func emptyDynamicConfiguration() *dynamic.Configuration { return &dynamic.Configuration{ HTTP: &dynamic.HTTPConfiguration{ Routers: make(map[string]*dynamic.Router), Middlewares: make(map[string]*dynamic.Middleware), Services: make(map[string]*dynamic.Service), ServersTransports: make(map[string]*dynamic.ServersTransport), }, TCP: &dynamic.TCPConfiguration{ Routers: make(map[string]*dynamic.TCPRouter), Services: make(map[string]*dynamic.TCPService), ServersTransports: make(map[string]*dynamic.TCPServersTransport), }, TLS: &dynamic.TLSConfiguration{ Stores: make(map[string]ttls.Store), Options: make(map[string]ttls.Options), }, UDP: &dynamic.UDPConfiguration{ Routers: make(map[string]*dynamic.UDPRouter), Services: make(map[string]*dynamic.UDPService), }, } } func createAgentClient(tlsCfg *TLS) (http.Client, error) { var client http.Client if tlsCfg.Insecure { client.Transport = &http.Transport{ TLSClientConfig: &tls.Config{ InsecureSkipVerify: true, MinVersion: tls.VersionTLS13, }, } return client, nil } caContent, err := tlsCfg.CA.Read() if err != nil { return client, fmt.Errorf("reading CA: %w", err) } roots := x509.NewCertPool() if ok := roots.AppendCertsFromPEM(caContent); !ok { return client, errors.New("appending CA error") } certContent, err := tlsCfg.Cert.Read() if err != nil { return client, fmt.Errorf("reading Cert: %w", err) } keyContent, err := tlsCfg.Key.Read() if err != nil { return client, fmt.Errorf("reading Key: %w", err) } certificate, err := tls.X509KeyPair(certContent, keyContent) if err != nil { return client, fmt.Errorf("creating key pair: %w", err) } // mTLS client.Transport = &http.Transport{ TLSClientConfig: &tls.Config{ RootCAs: roots, Certificates: []tls.Certificate{certificate}, ServerName: "agent.traefik", ClientAuth: tls.RequireAndVerifyClientCert, MinVersion: tls.VersionTLS13, }, } return client, nil }