Refactor acme tests and middleware for lazy domain resolution

1 files changed, 46 insertions, 0 deletions

diff --git a/internal/handlers/acme.go b/internal/handlers/acme.go
new file mode 100644
index 00000000..258aaebe
--- /dev/null
+++ b/internal/handlers/acme.go
@@ -0,0 +1,46 @@
+package handlers
+
+import (
+	"errors"
+	"net/http"
+	"net/url"
+
+	"gitlab.com/gitlab-org/gitlab-pages/internal/acme"
+	"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"
+)
+
+func AcmeMiddleware(handler http.Handler, s source.Source, gitlabURL string) http.Handler {
+	if gitlabURL == "" {
+		return handler
+	}
+
+	u, _ := url.Parse(gitlabURL)
+	fn := serveFromDomain(s)
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if acme.ServeAcmeChallenges(w, r, fn, u) {
+			return
+		}
+
+		handler.ServeHTTP(w, r)
+	})
+}
+
+func serveFromDomain(s source.Source) acme.FallbackStrategy {
+	return func(w http.ResponseWriter, r *http.Request) bool {
+		d, err := s.GetDomain(r.Context(), request.GetHostWithoutPort(r))
+
+		if err != nil && !errors.Is(err, domain.ErrDomainDoesNotExist) {
+			logging.LogRequest(r).WithError(err).Error("could not fetch domain information from a source")
+
+			httperrors.Serve502(w)
+			return true
+		}
+
+		return d.ServeFileHTTP(w, r)
+	}
+}