fork from codeberg.org

server/upstream/redirects.go

@@ -0,0 +1,107 @@
+package upstream
+
+import (
+	"strconv"
+	"strings"
+	"time"
+
+	"pages-server/server/cache"
+	"pages-server/server/context"
+	"pages-server/server/gitea"
+	"github.com/rs/zerolog/log"
+)
+
+type Redirect struct {
+	From       string
+	To         string
+	StatusCode int
+}
+
+// rewriteURL returns the destination URL and true if r matches reqURL.
+func (r *Redirect) rewriteURL(reqURL string) (dstURL string, ok bool) {
+	// check if from url matches request url
+	if strings.TrimSuffix(r.From, "/") == strings.TrimSuffix(reqURL, "/") {
+		return r.To, true
+	}
+	// handle wildcard redirects
+	if strings.HasSuffix(r.From, "/*") {
+		trimmedFromURL := strings.TrimSuffix(r.From, "/*")
+		if reqURL == trimmedFromURL || strings.HasPrefix(reqURL, trimmedFromURL+"/") {
+			if strings.Contains(r.To, ":splat") {
+				matched := strings.TrimPrefix(reqURL, trimmedFromURL)
+				matched = strings.TrimPrefix(matched, "/")
+				return strings.ReplaceAll(r.To, ":splat", matched), true
+			}
+			return r.To, true
+		}
+	}
+	return "", false
+}
+
+// redirectsCacheTimeout specifies the timeout for the redirects cache.
+var redirectsCacheTimeout = 10 * time.Minute
+
+const redirectsConfig = "_redirects"
+
+// getRedirects returns redirects specified in the _redirects file.
+func (o *Options) getRedirects(giteaClient *gitea.Client, redirectsCache cache.ICache) []Redirect {
+	var redirects []Redirect
+	cacheKey := o.TargetOwner + "/" + o.TargetRepo + "/" + o.TargetBranch
+
+	// Check for cached redirects
+	if cachedValue, ok := redirectsCache.Get(cacheKey); ok {
+		redirects = cachedValue.([]Redirect)
+	} else {
+		// Get _redirects file and parse
+		body, err := giteaClient.GiteaRawContent(o.TargetOwner, o.TargetRepo, o.TargetBranch, redirectsConfig)
+		if err == nil {
+			for _, line := range strings.Split(string(body), "\n") {
+				redirectArr := strings.Fields(line)
+
+				// Ignore comments and invalid lines
+				if strings.HasPrefix(line, "#") || len(redirectArr) < 2 {
+					continue
+				}
+
+				// Get redirect status code
+				statusCode := 301
+				if len(redirectArr) == 3 {
+					statusCode, err = strconv.Atoi(redirectArr[2])
+					if err != nil {
+						log.Info().Err(err).Msgf("could not read %s of %s/%s", redirectsConfig, o.TargetOwner, o.TargetRepo)
+					}
+				}
+
+				redirects = append(redirects, Redirect{
+					From:       redirectArr[0],
+					To:         redirectArr[1],
+					StatusCode: statusCode,
+				})
+			}
+		}
+		_ = redirectsCache.Set(cacheKey, redirects, redirectsCacheTimeout)
+	}
+	return redirects
+}
+
+func (o *Options) matchRedirects(ctx *context.Context, giteaClient *gitea.Client, redirects []Redirect, redirectsCache cache.ICache) (final bool) {
+	reqURL := ctx.Req.RequestURI
+	// remove repo and branch from request url
+	reqURL = strings.TrimPrefix(reqURL, "/"+o.TargetRepo)
+	reqURL = strings.TrimPrefix(reqURL, "/@"+o.TargetBranch)
+
+	for _, redirect := range redirects {
+		if dstURL, ok := redirect.rewriteURL(reqURL); ok {
+			// do rewrite if status code is 200
+			if redirect.StatusCode == 200 {
+				o.TargetPath = dstURL
+				o.Upstream(ctx, giteaClient, redirectsCache)
+			} else {
+				ctx.Redirect(dstURL, redirect.StatusCode)
+			}
+			return true
+		}
+	}
+
+	return false
+}