refactor: move middlewares to corresponding packages

1 files changed, 41 insertions, 0 deletions

diff --git a/internal/routing/middleware.go b/internal/routing/middleware.go
new file mode 100644
index 00000000..5f065c61
--- /dev/null
+++ b/internal/routing/middleware.go
@@ -0,0 +1,41 @@
+package routing
+
+import (
+	"errors"
+	"net/http"
+
+	"gitlab.com/gitlab-org/gitlab-pages/internal/domain"
+	"gitlab.com/gitlab-org/gitlab-pages/internal/httperrors"
+	"gitlab.com/gitlab-org/gitlab-pages/internal/logging"
+	"gitlab.com/gitlab-org/gitlab-pages/internal/request"
+	"gitlab.com/gitlab-org/gitlab-pages/internal/source"
+	"gitlab.com/gitlab-org/gitlab-pages/metrics"
+)
+
+// NewMiddleware returns middleware which determine the host and domain for the request, for
+// downstream middlewares to use
+func NewMiddleware(handler http.Handler, s source.Source) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// if we could not retrieve a domain from domains source we break the
+		// middleware chain and simply respond with 502 after logging this
+		host, d, err := getHostAndDomain(r, s)
+		if err != nil && !errors.Is(err, domain.ErrDomainDoesNotExist) {
+			metrics.DomainsSourceFailures.Inc()
+			logging.LogRequest(r).WithError(err).Error("could not fetch domain information from a source")
+
+			httperrors.Serve502(w)
+			return
+		}
+
+		r = request.WithHostAndDomain(r, host, d)
+
+		handler.ServeHTTP(w, r)
+	})
+}
+
+func getHostAndDomain(r *http.Request, s source.Source) (string, *domain.Domain, error) {
+	host := request.GetHostWithoutPort(r)
+	domain, err := s.GetDomain(r.Context(), host)
+
+	return host, domain, err
+}