fork from codeberg.org

server/upstream/domains.go

@@ -0,0 +1,70 @@
+package upstream
+
+import (
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/rs/zerolog/log"
+
+	"pages-server/server/cache"
+	"pages-server/server/gitea"
+)
+
+// canonicalDomainCacheTimeout specifies the timeout for the canonical domain cache.
+var canonicalDomainCacheTimeout = 15 * time.Minute
+
+const canonicalDomainConfig = ".domains"
+
+// CheckCanonicalDomain returns the canonical domain specified in the repo (using the `.domains` file).
+func (o *Options) CheckCanonicalDomain(giteaClient *gitea.Client, actualDomain, mainDomainSuffix string, canonicalDomainCache cache.ICache) (domain string, valid bool) {
+	// Check if this request is cached.
+	if cachedValue, ok := canonicalDomainCache.Get(o.TargetOwner + "/" + o.TargetRepo + "/" + o.TargetBranch); ok {
+		domains := cachedValue.([]string)
+		for _, domain := range domains {
+			if domain == actualDomain {
+				valid = true
+				break
+			}
+		}
+		return domains[0], valid
+	}
+
+	body, err := giteaClient.GiteaRawContent(o.TargetOwner, o.TargetRepo, o.TargetBranch, canonicalDomainConfig)
+	if err != nil && !errors.Is(err, gitea.ErrorNotFound) {
+		log.Error().Err(err).Msgf("could not read %s of %s/%s", canonicalDomainConfig, o.TargetOwner, o.TargetRepo)
+	}
+
+	var domains []string
+	for _, domain := range strings.Split(string(body), "\n") {
+		domain = strings.ToLower(domain)
+		domain = strings.TrimSpace(domain)
+		domain = strings.TrimPrefix(domain, "http://")
+		domain = strings.TrimPrefix(domain, "http://")
+		if domain != "" && !strings.HasPrefix(domain, "#") && !strings.ContainsAny(domain, "\t /") && strings.ContainsRune(domain, '.') {
+			domains = append(domains, domain)
+		}
+		if domain == actualDomain {
+			valid = true
+		}
+	}
+
+	// Add [owner].[pages-domain] as valid domain.
+	domains = append(domains, o.TargetOwner+mainDomainSuffix)
+	if domains[len(domains)-1] == actualDomain {
+		valid = true
+	}
+
+	// If the target repository isn't called pages, add `/[repository]` to the
+	// previous valid domain.
+	if o.TargetRepo != "" && o.TargetRepo != "pages" {
+		domains[len(domains)-1] += "/" + o.TargetRepo
+	}
+
+	// Add result to cache.
+	_ = canonicalDomainCache.Set(o.TargetOwner+"/"+o.TargetRepo+"/"+o.TargetBranch, domains, canonicalDomainCacheTimeout)
+
+	// Return the first domain from the list and return if any of the domains
+	// matched the requested domain.
+	return domains[0], valid
+}

server/upstream/header.go

@@ -0,0 +1,28 @@
+package upstream
+
+import (
+	"net/http"
+	"time"
+
+	"pages-server/server/context"
+	"pages-server/server/gitea"
+)
+
+// setHeader set values to response header
+func (o *Options) setHeader(ctx *context.Context, header http.Header) {
+	if eTag := header.Get(gitea.ETagHeader); eTag != "" {
+		ctx.RespWriter.Header().Set(gitea.ETagHeader, eTag)
+	}
+	if cacheIndicator := header.Get(gitea.PagesCacheIndicatorHeader); cacheIndicator != "" {
+		ctx.RespWriter.Header().Set(gitea.PagesCacheIndicatorHeader, cacheIndicator)
+	}
+	if length := header.Get(gitea.ContentLengthHeader); length != "" {
+		ctx.RespWriter.Header().Set(gitea.ContentLengthHeader, length)
+	}
+	if mime := header.Get(gitea.ContentTypeHeader); mime == "" || o.ServeRaw {
+		ctx.RespWriter.Header().Set(gitea.ContentTypeHeader, rawMime)
+	} else {
+		ctx.RespWriter.Header().Set(gitea.ContentTypeHeader, mime)
+	}
+	ctx.RespWriter.Header().Set(headerLastModified, o.BranchTimestamp.In(time.UTC).Format(http.TimeFormat))
+}

server/upstream/helper.go

@@ -0,0 +1,47 @@
+package upstream
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/rs/zerolog/log"
+
+	"pages-server/server/gitea"
+)
+
+// GetBranchTimestamp finds the default branch (if branch is "") and save branch and it's last modification time to Options
+func (o *Options) GetBranchTimestamp(giteaClient *gitea.Client) (bool, error) {
+	log := log.With().Strs("BranchInfo", []string{o.TargetOwner, o.TargetRepo, o.TargetBranch}).Logger()
+
+	if o.TargetBranch == "" {
+		// Get default branch
+		defaultBranch, err := giteaClient.GiteaGetRepoDefaultBranch(o.TargetOwner, o.TargetRepo)
+		if err != nil {
+			log.Err(err).Msg("Couldn't fetch default branch from repository")
+			return false, err
+		}
+		log.Debug().Msgf("Successfully fetched default branch %q from Gitea", defaultBranch)
+		o.TargetBranch = defaultBranch
+	}
+
+	timestamp, err := giteaClient.GiteaGetRepoBranchTimestamp(o.TargetOwner, o.TargetRepo, o.TargetBranch)
+	if err != nil {
+		if !errors.Is(err, gitea.ErrorNotFound) {
+			log.Error().Err(err).Msg("Could not get latest commit timestamp from branch")
+		}
+		return false, err
+	}
+
+	if timestamp == nil || timestamp.Branch == "" {
+		return false, fmt.Errorf("empty response")
+	}
+
+	log.Debug().Msgf("Successfully fetched latest commit timestamp from branch: %#v", timestamp)
+	o.BranchTimestamp = timestamp.Timestamp
+	o.TargetBranch = timestamp.Branch
+	return true, nil
+}
+
+func (o *Options) ContentWebLink(giteaClient *gitea.Client) string {
+	return giteaClient.ContentWebLink(o.TargetOwner, o.TargetRepo, o.TargetBranch, o.TargetPath) + "; rel=\"canonical\""
+}

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
+}

server/upstream/redirects_test.go

@@ -0,0 +1,36 @@
+package upstream
+
+import (
+	"testing"
+)
+
+func TestRedirect_rewriteURL(t *testing.T) {
+	for _, tc := range []struct {
+		redirect   Redirect
+		reqURL     string
+		wantDstURL string
+		wantOk     bool
+	}{
+		{Redirect{"/", "/dst", 200}, "/", "/dst", true},
+		{Redirect{"/", "/dst", 200}, "/foo", "", false},
+		{Redirect{"/src", "/dst", 200}, "/src", "/dst", true},
+		{Redirect{"/src", "/dst", 200}, "/foo", "", false},
+		{Redirect{"/src", "/dst", 200}, "/src/foo", "", false},
+		{Redirect{"/*", "/dst", 200}, "/", "/dst", true},
+		{Redirect{"/*", "/dst", 200}, "/src", "/dst", true},
+		{Redirect{"/src/*", "/dst/:splat", 200}, "/src", "/dst/", true},
+		{Redirect{"/src/*", "/dst/:splat", 200}, "/src/", "/dst/", true},
+		{Redirect{"/src/*", "/dst/:splat", 200}, "/src/foo", "/dst/foo", true},
+		{Redirect{"/src/*", "/dst/:splat", 200}, "/src/foo/bar", "/dst/foo/bar", true},
+		{Redirect{"/src/*", "/dst/:splatsuffix", 200}, "/src/foo", "/dst/foosuffix", true},
+		{Redirect{"/src/*", "/dst:splat", 200}, "/src/foo", "/dstfoo", true},
+		{Redirect{"/src/*", "/dst", 200}, "/srcfoo", "", false},
+		// This is the example from FEATURES.md:
+		{Redirect{"/articles/*", "/posts/:splat", 302}, "/articles/2022/10/12/post-1/", "/posts/2022/10/12/post-1/", true},
+	} {
+		if dstURL, ok := tc.redirect.rewriteURL(tc.reqURL); dstURL != tc.wantDstURL || ok != tc.wantOk {
+			t.Errorf("%#v.rewriteURL(%q) = %q, %v; want %q, %v",
+				tc.redirect, tc.reqURL, dstURL, ok, tc.wantDstURL, tc.wantOk)
+		}
+	}
+}

server/upstream/upstream.go

@@ -0,0 +1,225 @@
+package upstream
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+
+	"pages-server/html"
+	"pages-server/server/cache"
+	"pages-server/server/context"
+	"pages-server/server/gitea"
+)
+
+const (
+	headerLastModified    = "Last-Modified"
+	headerIfModifiedSince = "If-Modified-Since"
+
+	rawMime = "text/plain; charset=utf-8"
+)
+
+var upstreamIndexPages = []string{
+	"index.html",
+}
+
+var upstreamNotFoundPages = []string{
+	"404.html",
+}
+
+type Options struct {
+	TargetOwner  string
+	TargetRepo   string
+	TargetBranch string
+	TargetPath   string
+
+	Host string
+
+	TryIndexPages   bool
+	BranchTimestamp time.Time
+
+	appendTrailingSlash bool
+	redirectIfExists    string
+
+	ServeRaw bool
+}
+
+func (o *Options) Upstream(ctx *context.Context, giteaClient *gitea.Client, redirectsCache cache.ICache) bool {
+	log := log.With().Strs("upstream", []string{o.TargetOwner, o.TargetRepo, o.TargetBranch, o.TargetPath}).Logger()
+
+	log.Debug().Msg("Start")
+
+	if o.TargetOwner == "" || o.TargetRepo == "" {
+		html.ReturnErrorPage(ctx, "forge client: either repo owner or name info is missing", http.StatusBadRequest)
+		return false
+	}
+
+	if o.BranchTimestamp.IsZero() {
+		branchExist, err := o.GetBranchTimestamp(giteaClient)
+		if err != nil && errors.Is(err, gitea.ErrorNotFound) || !branchExist {
+			html.ReturnErrorPage(ctx,
+				fmt.Sprintf("branch <code>%q</code> for <code>%s/%s</code> not found", o.TargetBranch, o.TargetOwner, o.TargetRepo),
+				http.StatusNotFound)
+			return false
+		}
+
+		if err != nil {
+			html.ReturnErrorPage(ctx,
+				fmt.Sprintf("could not get timestamp of branch <code>%q</code>: '%v'", o.TargetBranch, err),
+				http.StatusFailedDependency)
+			return false
+		}
+	}
+
+	if ctx.Response() != nil {
+		ifModifiedSince, err := time.Parse(time.RFC1123, ctx.Response().Header.Get(headerIfModifiedSince))
+		if err == nil && ifModifiedSince.After(o.BranchTimestamp) {
+			ctx.RespWriter.WriteHeader(http.StatusNotModified)
+			log.Trace().Msg("check response against last modified: valid")
+			return true
+		}
+		log.Trace().Msg("check response against last modified: outdated")
+	}
+
+	reader, header, statusCode, err := giteaClient.ServeRawContent(o.TargetOwner, o.TargetRepo, o.TargetBranch, o.TargetPath)
+	if err != nil {
+		handleGiteaError(ctx, log, err, statusCode)
+		return false
+	}
+
+	defer func() {
+		if reader != nil {
+			reader.Close()
+		}
+	}()
+
+	if errors.Is(err, gitea.ErrorNotFound) {
+		handleNotFound(ctx, log, giteaClient, redirectsCache, o)
+		return false
+	}
+
+	if err != nil || reader == nil || statusCode != http.StatusOK {
+		handleUnexpectedError(ctx, log, err, statusCode)
+		return false
+	}
+
+	handleRedirects(ctx, log, o, redirectsCache)
+	setHeaders(ctx, header)
+	writeResponse(ctx, reader)
+
+	return true
+}
+
+func handleGiteaError(ctx *context.Context, log zerolog.Logger, err error, statusCode int) {
+	var msg string
+	if err != nil {
+		msg = "forge client: returned unexpected error"
+		log.Error().Err(err).Msg(msg)
+		msg = fmt.Sprintf("%s: '%v'", msg, err)
+	}
+	if statusCode != http.StatusOK {
+		msg = fmt.Sprintf("forge client: couldn't fetch contents: <code>%d - %s</code>", statusCode, http.StatusText(statusCode))
+		log.Error().Msg(msg)
+	}
+
+	html.ReturnErrorPage(ctx, msg, http.StatusInternalServerError)
+}
+
+func handleNotFound(ctx *context.Context, log zerolog.Logger, giteaClient *gitea.Client, redirectsCache cache.ICache, o *Options) {
+	log.Debug().Msg("Handling not found error")
+	redirects := o.getRedirects(giteaClient, redirectsCache)
+	if o.matchRedirects(ctx, giteaClient, redirects, redirectsCache) {
+		log.Trace().Msg("redirect")
+		return
+	}
+
+	if o.TryIndexPages {
+		log.Trace().Msg("try index page")
+		optionsForIndexPages := *o
+		optionsForIndexPages.TryIndexPages = false
+		optionsForIndexPages.appendTrailingSlash = true
+		for _, indexPage := range upstreamIndexPages {
+			optionsForIndexPages.TargetPath = strings.TrimSuffix(o.TargetPath, "/") + "/" + indexPage
+			if optionsForIndexPages.Upstream(ctx, giteaClient, redirectsCache) {
+				return
+			}
+		}
+		log.Trace().Msg("try html file with path name")
+		optionsForIndexPages.appendTrailingSlash = false
+		optionsForIndexPages.redirectIfExists = strings.TrimSuffix(ctx.Path(), "/") + ".html"
+		optionsForIndexPages.TargetPath = o.TargetPath + ".html"
+		if optionsForIndexPages.Upstream(ctx, giteaClient, redirectsCache) {
+			return
+		}
+	}
+
+	log.Trace().Msg("not found")
+	ctx.StatusCode = http.StatusNotFound
+
+	if o.TryIndexPages {
+		log.Trace().Msg("try not found page")
+		optionsForNotFoundPages := *o
+		optionsForNotFoundPages.TryIndexPages = false
+		optionsForNotFoundPages.appendTrailingSlash = false
+		for _, notFoundPage := range upstreamNotFoundPages {
+			optionsForNotFoundPages.TargetPath = "/" + notFoundPage
+			if optionsForNotFoundPages.Upstream(ctx, giteaClient, redirectsCache) {
+				return
+			}
+		}
+		log.Trace().Msg("not found page missing")
+	}
+}
+
+func handleUnexpectedError(ctx *context.Context, log zerolog.Logger, err error, statusCode int) {
+	var msg string
+	if err != nil {
+		msg = "forge client: returned unexpected error"
+		log.Error().Err(err).Msg(msg)
+		msg = fmt.Sprintf("%s: '%v'", msg, err)
+	}
+	if statusCode != http.StatusOK {
+		msg = fmt.Sprintf("forge client: couldn't fetch contents: <code>%d - %s</code>", statusCode, http.StatusText(statusCode))
+		log.Error().Msg(msg)
+	}
+
+	html.ReturnErrorPage(ctx, msg, http.StatusInternalServerError)
+}
+
+func handleRedirects(ctx *context.Context, log zerolog.Logger, o *Options, redirectsCache cache.ICache) {
+	if o.appendTrailingSlash && !strings.HasSuffix(ctx.Path(), "/") {
+		log.Trace().Msg("append trailing slash and redirect")
+		ctx.Redirect(ctx.Path()+"/", http.StatusTemporaryRedirect)
+		return
+	}
+	if strings.HasSuffix(ctx.Path(), "/index.html") && !o.ServeRaw {
+		log.Trace().Msg("remove index.html from path and redirect")
+		ctx.Redirect(strings.TrimSuffix(ctx.Path(), "index.html"), http.StatusTemporaryRedirect)
+		return
+	}
+	if o.redirectIfExists != "" {
+		ctx.Redirect(o.redirectIfExists, http.StatusTemporaryRedirect)
+		return
+	}
+}
+
+func setHeaders(ctx *context.Context, header http.Header) {
+	ctx.RespWriter.Header().Set("ETag", header.Get("ETag"))
+	ctx.RespWriter.Header().Set("Content-Type", header.Get("Content-Type"))
+}
+
+func writeResponse(ctx *context.Context, reader io.Reader) {
+	ctx.RespWriter.WriteHeader(ctx.StatusCode)
+	if reader != nil {
+		_, err := io.Copy(ctx.RespWriter, reader)
+		if err != nil {
+			log.Error().Err(err).Msgf("Couldn't write body for %q", ctx.Path())
+			html.ReturnErrorPage(ctx, "", http.StatusInternalServerError)
+		}
+	}
+}

server/upstream/upstream.gov1

@@ -0,0 +1,220 @@
+package upstream
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/rs/zerolog/log"
+
+	"pages-server/html"
+	"pages-server/server/cache"
+	"pages-server/server/context"
+	"pages-server/server/gitea"
+)
+
+const (
+	headerLastModified    = "Last-Modified"
+	headerIfModifiedSince = "If-Modified-Since"
+
+	rawMime = "text/plain; charset=utf-8"
+)
+
+// upstreamIndexPages lists pages that may be considered as index pages for directories.
+var upstreamIndexPages = []string{
+	"index.html",
+}
+
+// upstreamNotFoundPages lists pages that may be considered as custom 404 Not Found pages.
+var upstreamNotFoundPages = []string{
+	"404.html",
+}
+
+// Options provides various options for the upstream request.
+type Options struct {
+	TargetOwner  string
+	TargetRepo   string
+	TargetBranch string
+	TargetPath   string
+
+	// Used for debugging purposes.
+	Host string
+
+	TryIndexPages   bool
+	BranchTimestamp time.Time
+	// internal
+	appendTrailingSlash bool
+	redirectIfExists    string
+
+	ServeRaw bool
+}
+
+// Upstream requests a file from the Gitea API at GiteaRoot and writes it to the request context.
+func (o *Options) Upstream(ctx *context.Context, giteaClient *gitea.Client, redirectsCache cache.ICache) bool {
+	log := log.With().Strs("upstream", []string{o.TargetOwner, o.TargetRepo, o.TargetBranch, o.TargetPath}).Logger()
+
+	log.Debug().Msg("Start")
+
+	if o.TargetOwner == "" || o.TargetRepo == "" {
+		html.ReturnErrorPage(ctx, "forge client: either repo owner or name info is missing", http.StatusBadRequest)
+		return true
+	}
+
+	// Check if the branch exists and when it was modified
+	if o.BranchTimestamp.IsZero() {
+		branchExist, err := o.GetBranchTimestamp(giteaClient)
+		// handle 404
+		if err != nil && errors.Is(err, gitea.ErrorNotFound) || !branchExist {
+			html.ReturnErrorPage(ctx,
+				fmt.Sprintf("branch <code>%q</code> for <code>%s/%s</code> not found", o.TargetBranch, o.TargetOwner, o.TargetRepo),
+				http.StatusNotFound)
+			return true
+		}
+
+		// handle unexpected errors
+		if err != nil {
+			html.ReturnErrorPage(ctx,
+				fmt.Sprintf("could not get timestamp of branch <code>%q</code>: '%v'", o.TargetBranch, err),
+				http.StatusFailedDependency)
+			return true
+		}
+	}
+
+	// Check if the browser has a cached version
+	if ctx.Response() != nil {
+		if ifModifiedSince, err := time.Parse(time.RFC1123, ctx.Response().Header.Get(headerIfModifiedSince)); err == nil {
+			if ifModifiedSince.After(o.BranchTimestamp) {
+				ctx.RespWriter.WriteHeader(http.StatusNotModified)
+				log.Trace().Msg("check response against last modified: valid")
+				return true
+			}
+		}
+		log.Trace().Msg("check response against last modified: outdated")
+	}
+
+	log.Debug().Msg("Preparing")
+
+	reader, header, statusCode, err := giteaClient.ServeRawContent(o.TargetOwner, o.TargetRepo, o.TargetBranch, o.TargetPath)
+	if reader != nil {
+		defer reader.Close()
+	}
+
+	log.Debug().Msg("Aquisting")
+
+	// Handle not found error
+	if err != nil && errors.Is(err, gitea.ErrorNotFound) {
+		log.Debug().Msg("Handling not found error")
+		// Get and match redirects
+		redirects := o.getRedirects(giteaClient, redirectsCache)
+		if o.matchRedirects(ctx, giteaClient, redirects, redirectsCache) {
+			log.Trace().Msg("redirect")
+			return true
+		}
+
+		if o.TryIndexPages {
+			log.Trace().Msg("try index page")
+			// copy the o struct & try if an index page exists
+			optionsForIndexPages := *o
+			optionsForIndexPages.TryIndexPages = false
+			optionsForIndexPages.appendTrailingSlash = true
+			for _, indexPage := range upstreamIndexPages {
+				optionsForIndexPages.TargetPath = strings.TrimSuffix(o.TargetPath, "/") + "/" + indexPage
+				if optionsForIndexPages.Upstream(ctx, giteaClient, redirectsCache) {
+					return true
+				}
+			}
+			log.Trace().Msg("try html file with path name")
+			// compatibility fix for GitHub Pages (/example → /example.html)
+			optionsForIndexPages.appendTrailingSlash = false
+			optionsForIndexPages.redirectIfExists = strings.TrimSuffix(ctx.Path(), "/") + ".html"
+			optionsForIndexPages.TargetPath = o.TargetPath + ".html"
+			if optionsForIndexPages.Upstream(ctx, giteaClient, redirectsCache) {
+				return true
+			}
+		}
+
+		log.Trace().Msg("not found")
+
+		ctx.StatusCode = http.StatusNotFound
+		if o.TryIndexPages {
+			log.Trace().Msg("try not found page")
+			// copy the o struct & try if a not found page exists
+			optionsForNotFoundPages := *o
+			optionsForNotFoundPages.TryIndexPages = false
+			optionsForNotFoundPages.appendTrailingSlash = false
+			for _, notFoundPage := range upstreamNotFoundPages {
+				optionsForNotFoundPages.TargetPath = "/" + notFoundPage
+				if optionsForNotFoundPages.Upstream(ctx, giteaClient, redirectsCache) {
+					return true
+				}
+			}
+			log.Trace().Msg("not found page missing")
+		}
+
+		return false
+	}
+
+	// handle unexpected client errors
+	if err != nil || reader == nil || statusCode != http.StatusOK {
+		log.Debug().Msg("Handling error")
+		var msg string
+
+		if err != nil {
+			msg = "forge client: returned unexpected error"
+			log.Error().Err(err).Msg(msg)
+			msg = fmt.Sprintf("%s: '%v'", msg, err)
+		}
+		if reader == nil {
+			msg = "forge client: returned no reader"
+			log.Error().Msg(msg)
+		}
+		if statusCode != http.StatusOK {
+			msg = fmt.Sprintf("forge client: couldn't fetch contents: <code>%d - %s</code>", statusCode, http.StatusText(statusCode))
+			log.Error().Msg(msg)
+		}
+
+		html.ReturnErrorPage(ctx, msg, http.StatusInternalServerError)
+		return true
+	}
+
+	// Append trailing slash if missing (for index files), and redirect to fix filenames in general
+	// o.appendTrailingSlash is only true when looking for index pages
+	if o.appendTrailingSlash && !strings.HasSuffix(ctx.Path(), "/") {
+		log.Trace().Msg("append trailing slash and redirect")
+		ctx.Redirect(ctx.Path()+"/", http.StatusTemporaryRedirect)
+		return true
+	}
+	if strings.HasSuffix(ctx.Path(), "/index.html") && !o.ServeRaw {
+		log.Trace().Msg("remove index.html from path and redirect")
+		ctx.Redirect(strings.TrimSuffix(ctx.Path(), "index.html"), http.StatusTemporaryRedirect)
+		return true
+	}
+	if o.redirectIfExists != "" {
+		ctx.Redirect(o.redirectIfExists, http.StatusTemporaryRedirect)
+		return true
+	}
+
+	// Set ETag & MIME
+	o.setHeader(ctx, header)
+
+	log.Debug().Msg("Prepare response")
+
+	ctx.RespWriter.WriteHeader(ctx.StatusCode)
+
+	// Write the response body to the original request
+	if reader != nil {
+		_, err := io.Copy(ctx.RespWriter, reader)
+		if err != nil {
+			log.Error().Err(err).Msgf("Couldn't write body for %q", o.TargetPath)
+			html.ReturnErrorPage(ctx, "", http.StatusInternalServerError)
+			return true
+		}
+	}
+
+	log.Debug().Msg("Sending response")
+
+	return true
+}