feat: initial commit

internal/proxy/middleware/director/director.go

@@ -0,0 +1,90 @@
+package director
+
+import (
+	"context"
+	"net/http"
+	"net/url"
+
+	"forge.cadoles.com/Cadoles/go-proxy"
+	"forge.cadoles.com/Cadoles/go-proxy/wildcard"
+	"forge.cadoles.com/cadoles/bouncer/internal/store"
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
+)
+
+type Director struct {
+	repo store.ProxyRepository
+}
+
+func (d *Director) rewriteRequest(r *http.Request) error {
+	ctx := r.Context()
+
+	proxies, err := d.getProxies(ctx)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	var match *url.URL
+
+MAIN:
+	for _, p := range proxies {
+		for _, from := range p.From {
+			if matches := wildcard.Match(r.Host, from); !matches {
+				continue
+			}
+
+			match = p.To
+			break MAIN
+		}
+	}
+
+	if match == nil {
+		return nil
+	}
+
+	r.URL.Host = match.Host
+	r.URL.Scheme = match.Scheme
+
+	return nil
+}
+
+func (d *Director) getProxies(ctx context.Context) ([]*store.Proxy, error) {
+	headers, err := d.repo.QueryProxy(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	proxies := make([]*store.Proxy, len(headers))
+
+	for i, h := range headers {
+		proxy, err := d.repo.GetProxy(ctx, h.ID)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		proxies[i] = proxy
+	}
+
+	return proxies, nil
+}
+
+func (d *Director) Middleware() proxy.Middleware {
+	return func(next http.Handler) http.Handler {
+		fn := func(w http.ResponseWriter, r *http.Request) {
+			if err := d.rewriteRequest(r); 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
+			}
+
+			next.ServeHTTP(w, r)
+		}
+
+		return http.HandlerFunc(fn)
+	}
+}
+
+func New(repo store.ProxyRepository) *Director {
+	return &Director{repo}
+}