Add anonymous authenticator for tests

Author: simonpasquier

authentication/anonymous.go

@@ -0,0 +1,60 @@
+package authentication
+
+import (
+	"context"
+	"net/http"
+	"os"
+
+	"github.com/go-kit/log"
+	"github.com/go-kit/log/level"
+	grpc_middleware_auth "github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/auth"
+	"github.com/prometheus/client_golang/prometheus"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+// AnonymousAuthenticatorType represents the anonymous authentication provider
+// type.
+//
+// It always authenticates the incoming request and sets the subject's name to
+// 'anonymous'. It should only be used for tests and it requires the
+// INSECURE_ANONYMOUS_AUTHENTICATOR_ENABLED environment variable to be set to
+// 1.
+const AnonymousAuthenticatorType = "anonymous"
+
+func init() {
+	if v := os.Getenv("INSECURE_ANONYMOUS_AUTHENTICATOR_ENABLED"); v == "1" {
+		onboardNewProvider(AnonymousAuthenticatorType, anonymousAuthenticatorType)
+	}
+}
+
+func anonymousAuthenticatorType(_ map[string]interface{}, _ string, _ *prometheus.CounterVec, logger log.Logger) (Provider, error) {
+	level.Warn(logger).Log("msg", "using anonymous authenticator")
+	return &anonymousAuthenticator{}, nil
+}
+
+type anonymousAuthenticator struct{}
+
+// Middleware implements the Provider interface.
+func (a *anonymousAuthenticator) Middleware() Middleware {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ctx := context.WithValue(r.Context(), subjectKey, "anonymous")
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+// GRPCMiddleware implements the Provider interface.
+// It isn't yet implemented.
+func (a *anonymousAuthenticator) GRPCMiddleware() grpc.StreamServerInterceptor {
+	return grpc_middleware_auth.StreamServerInterceptor(func(ctx context.Context) (context.Context, error) {
+		return ctx, status.Error(codes.Unimplemented, "internal error")
+	})
+}
+
+// Handler implements the Provider interface.
+func (a *anonymousAuthenticator) Handler() (string, http.Handler) {
+	return "", nil
+}