proxy: add route portal json (#5428)

* proxy: add route portal json

* fix 405 issue

* add link to issue

* Update proxy/portal/filter_test.go

Co-authored-by: Kenneth Jenkins <51246568+kenjenkins@users.noreply.github.com>

---------

Co-authored-by: Kenneth Jenkins <51246568+kenjenkins@users.noreply.github.com>

proxy/handlers_portal.go

@@ -0,0 +1,56 @@
+package proxy
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/pomerium/pomerium/config"
+	"github.com/pomerium/pomerium/internal/handlers"
+	"github.com/pomerium/pomerium/internal/httputil"
+	"github.com/pomerium/pomerium/proxy/portal"
+)
+
+func (p *Proxy) routesPortalJSON(w http.ResponseWriter, r *http.Request) error {
+	u := p.getUserInfoData(r)
+	rs := p.getPortalRoutes(u)
+	m := map[string]any{}
+	m["routes"] = rs
+
+	b, err := json.Marshal(m)
+	if err != nil {
+		return httputil.NewError(http.StatusInternalServerError, err)
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write(b)
+	return nil
+}
+
+func (p *Proxy) getPortalRoutes(u handlers.UserInfoData) []portal.Route {
+	options := p.currentOptions.Load()
+	pu := p.getPortalUser(u)
+	var routes []*config.Policy
+	for route := range options.GetAllPolicies() {
+		if portal.CheckRouteAccess(pu, route) {
+			routes = append(routes, route)
+		}
+	}
+	return portal.RoutesFromConfigRoutes(routes)
+}
+
+func (p *Proxy) getPortalUser(u handlers.UserInfoData) portal.User {
+	pu := portal.User{}
+	pu.SessionID = u.Session.GetId()
+	pu.UserID = u.User.GetId()
+	pu.Email = u.User.GetEmail()
+	for _, dg := range u.DirectoryGroups {
+		if v := dg.ID; v != "" {
+			pu.Groups = append(pu.Groups, dg.ID)
+		}
+		if v := dg.Name; v != "" {
+			pu.Groups = append(pu.Groups, dg.Name)
+		}
+	}
+	return pu
+}