package director import ( "context" "net/http" "net/url" "sort" "forge.cadoles.com/Cadoles/go-proxy" "forge.cadoles.com/Cadoles/go-proxy/wildcard" "forge.cadoles.com/cadoles/bouncer/internal/store" "github.com/pkg/errors" "github.com/prometheus/client_golang/prometheus" "gitlab.com/wpetit/goweb/logger" ) type Director struct { proxyRepository store.ProxyRepository layerRepository store.LayerRepository layerRegistry *LayerRegistry } func (d *Director) rewriteRequest(r *http.Request) (*http.Request, error) { ctx := r.Context() proxies, err := d.getProxies(ctx) if err != nil { return r, errors.WithStack(err) } var match *store.Proxy MAIN: for _, p := range proxies { for _, from := range p.From { if matches := wildcard.Match(r.Host, from); !matches { continue } match = p break MAIN } } if match == nil { return r, nil } toURL, err := url.Parse(match.To) if err != nil { return r, errors.WithStack(err) } r.URL.Host = toURL.Host r.URL.Scheme = toURL.Scheme ctx = logger.With(ctx, logger.F("proxy", match.Name), logger.F("host", r.Host), logger.F("remoteAddr", r.RemoteAddr), ) metricProxyRequestsTotal.With(prometheus.Labels{metricLabelProxy: string(match.Name)}).Add(1) ctx = withProxy(ctx, match) layers, err := d.getLayers(ctx, match.Name) if err != nil { return r, errors.WithStack(err) } ctx = withLayers(ctx, layers) r = r.WithContext(ctx) return r, nil } func (d *Director) getProxies(ctx context.Context) ([]*store.Proxy, error) { headers, err := d.proxyRepository.QueryProxy(ctx, store.WithProxyQueryEnabled(true)) if err != nil { return nil, errors.WithStack(err) } sort.Sort(store.ByProxyWeight(headers)) proxies := make([]*store.Proxy, 0, len(headers)) for _, h := range headers { if !h.Enabled { continue } proxy, err := d.proxyRepository.GetProxy(ctx, h.Name) if err != nil { return nil, errors.WithStack(err) } proxies = append(proxies, proxy) } return proxies, nil } func (d *Director) getLayers(ctx context.Context, proxyName store.ProxyName) ([]*store.Layer, error) { headers, err := d.layerRepository.QueryLayers(ctx, proxyName, store.WithLayerQueryEnabled(true)) if err != nil { return nil, errors.WithStack(err) } sort.Sort(store.ByLayerWeight(headers)) layers := make([]*store.Layer, 0, len(headers)) for _, h := range headers { if !h.Enabled { continue } layer, err := d.layerRepository.GetLayer(ctx, proxyName, h.Name) if err != nil { return nil, errors.WithStack(err) } layers = append(layers, layer) } return layers, nil } func (d *Director) RequestTransformer() proxy.RequestTransformer { return func(r *http.Request) { ctx := r.Context() layers, err := ctxLayers(ctx) if err != nil { if errors.Is(err, errContextKeyNotFound) { return } logger.Error(ctx, "could not retrieve layers from context", logger.E(errors.WithStack(err))) return } for _, layer := range layers { transformerLayer, ok := d.layerRegistry.GetRequestTransformer(layer.Type) if !ok { continue } transformer := transformerLayer.RequestTransformer(layer) transformer(r) } } } func (d *Director) ResponseTransformer() proxy.ResponseTransformer { return func(r *http.Response) error { ctx := r.Request.Context() layers, err := ctxLayers(ctx) if err != nil { if errors.Is(err, errContextKeyNotFound) { return nil } return errors.WithStack(err) } for _, layer := range layers { transformerLayer, ok := d.layerRegistry.GetResponseTransformer(layer.Type) if !ok { continue } transformer := transformerLayer.ResponseTransformer(layer) if err := transformer(r); err != nil { return errors.WithStack(err) } } return nil } } func (d *Director) Middleware() proxy.Middleware { return func(next http.Handler) http.Handler { fn := func(w http.ResponseWriter, r *http.Request) { r, err := d.rewriteRequest(r) if err != nil { logger.Error(r.Context(), "could not rewrite request", logger.E(errors.WithStack(err))) http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError) return } ctx := r.Context() layers, err := ctxLayers(ctx) if err != nil { if errors.Is(err, errContextKeyNotFound) { return } logger.Error(ctx, "could not retrieve proxy and layers from context", logger.E(errors.WithStack(err))) http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError) return } httpMiddlewares := make([]proxy.Middleware, 0) for _, layer := range layers { middleware, ok := d.layerRegistry.GetMiddleware(layer.Type) if !ok { continue } httpMiddlewares = append(httpMiddlewares, middleware.Middleware(layer)) } handler := createMiddlewareChain(next, httpMiddlewares) handler.ServeHTTP(w, r) } return http.HandlerFunc(fn) } } func New(proxyRepository store.ProxyRepository, layerRepository store.LayerRepository, layers ...Layer) *Director { registry := NewLayerRegistry(layers...) return &Director{proxyRepository, layerRepository, registry} }