vegvisir/pkg/server/router.go

//           ___   ____               ___       ___
// \ \  / / | _   |  __| \ \  / / || | __  || || _ |
//  \ \/ /  |___  | |__   \ \/ /  || |___  || ||___|
//   \  /   | _   | _  |   \  /   ||  __ | || ||\\
//    \/    |___  |___ |    \/    || ____| || || \\
//
// Copyright (c) 2021 Piotr Biernat. https://pbiernat.dev. MIT License
// Repo: https://git.pbiernat.dev/golang/vegvisir

package server

import (
	"fmt"
	"regexp"
	"strings"
	"vegvisir/pkg/cache"
	"vegvisir/pkg/config"
)

type Router struct {
	config *config.Config
	rcm    cache.RouteCacheManager     // Redis cache
	rCache map[string]cache.RouteCache // Internal route cache - TMP?
}

type Route struct {
	SourceUrl string
	TargetUrl string
}

func NewRouter(conf *config.Config, cacheDS cache.CacheDatastore, ttl int) *Router {
	return &Router{
		config: conf,
		rcm:    cache.NewRouteCacheManager(cacheDS, ttl),
		rCache: make(map[string]cache.RouteCache),
	}
}

func (r *Router) FindByRequestURL(url []byte) (bool, Route) {
	var sUrl string = string(url)

	for bId := range r.config.Backends {
		bck := r.config.Backends[bId]
		if !strings.Contains(sUrl, bck.PrefixUrl) {
			continue
		}

		for rId := range bck.Routes {
			routeCfg := &bck.Routes[rId]

			// if ok, cRoute := s.rCacheManager.Load(sUri); ok {
			// 	return true, cRoute
			// }
			if cRoute, ok := r.rCache[sUrl]; ok {
				route := Route{
					SourceUrl: cRoute.SourceUrl,
					TargetUrl: cRoute.TargetUrl,
				}
				return true, route
			}

			rgxp := regexp.MustCompile(fmt.Sprintf("%s%s", bck.PrefixUrl, routeCfg.Pattern))
			if rgxp.Match(url) {
				targetUrl := bck.BackendAddress + rgxp.ReplaceAllString(sUrl, routeCfg.Target)

				route := Route{
					SourceUrl: sUrl,
					TargetUrl: targetUrl,
				}

				// s.rCacheManager.Save(sUri, cRoute)
				r.rCache[sUrl] = cache.RouteCache{
					SourceUrl: route.SourceUrl,
					TargetUrl: route.TargetUrl,
				}

				return true, route
			}
		}
	}

	return false, Route{}
}