pages-server/server/upstream/upstream.go
2021-12-05 16:24:26 +01:00

194 lines
7.1 KiB
Go

package upstream
import (
"bytes"
"fmt"
"io"
"mime"
"path"
"strconv"
"strings"
"time"
"github.com/rs/zerolog/log"
"github.com/valyala/fasthttp"
"codeberg.org/codeberg/pages/html"
"codeberg.org/codeberg/pages/server/cache"
)
// upstreamIndexPages lists pages that may be considered as index pages for directories.
var upstreamIndexPages = []string{
"index.html",
}
// Options provides various options for the upstream request.
type Options struct {
DefaultMimeType string
ForbiddenMimeTypes map[string]struct{}
TryIndexPages bool
AppendTrailingSlash bool
RedirectIfExists string
BranchTimestamp time.Time
}
var client = fasthttp.Client{
ReadTimeout: 10 * time.Second,
MaxConnDuration: 60 * time.Second,
MaxConnWaitTimeout: 1000 * time.Millisecond,
MaxConnsPerHost: 128 * 16, // TODO: adjust bottlenecks for best performance with Gitea!
}
// Upstream requests a file from the Gitea API at GiteaRoot and writes it to the request context.
func (options *Options) Upstream(ctx *fasthttp.RequestCtx, targetOwner, targetRepo, targetBranch, targetPath, giteaRoot, giteaApiToken string, branchTimestampCache, fileResponseCache cache.SetGetKey) (final bool) {
log := log.With().Strs("upstream", []string{targetOwner, targetRepo, targetBranch, targetPath}).Logger()
if options.ForbiddenMimeTypes == nil {
options.ForbiddenMimeTypes = map[string]struct{}{}
}
// Check if the branch exists and when it was modified
if options.BranchTimestamp == (time.Time{}) {
branch := GetBranchTimestamp(targetOwner, targetRepo, targetBranch, giteaRoot, giteaApiToken, branchTimestampCache)
if branch == nil {
html.ReturnErrorPage(ctx, fasthttp.StatusFailedDependency)
return true
}
targetBranch = branch.Branch
options.BranchTimestamp = branch.Timestamp
}
if targetOwner == "" || targetRepo == "" || targetBranch == "" {
html.ReturnErrorPage(ctx, fasthttp.StatusBadRequest)
return true
}
// Check if the browser has a cached version
if ifModifiedSince, err := time.Parse(time.RFC1123, string(ctx.Request.Header.Peek("If-Modified-Since"))); err == nil {
if !ifModifiedSince.Before(options.BranchTimestamp) {
ctx.Response.SetStatusCode(fasthttp.StatusNotModified)
return true
}
}
log.Debug().Msg("preparations")
// Make a GET request to the upstream URL
uri := targetOwner + "/" + targetRepo + "/raw/" + targetBranch + "/" + targetPath
var req *fasthttp.Request
var res *fasthttp.Response
var cachedResponse fileResponse
var err error
if cachedValue, ok := fileResponseCache.Get(uri + "?timestamp=" + strconv.FormatInt(options.BranchTimestamp.Unix(), 10)); ok && len(cachedValue.(fileResponse).body) > 0 {
cachedResponse = cachedValue.(fileResponse)
} else {
req = fasthttp.AcquireRequest()
req.SetRequestURI(giteaRoot + "/api/v1/repos/" + uri + "?access_token=" + giteaApiToken)
res = fasthttp.AcquireResponse()
res.SetBodyStream(&strings.Reader{}, -1)
err = client.Do(req, res)
}
log.Debug().Msg("acquisition")
// Handle errors
if (res == nil && !cachedResponse.exists) || (res != nil && res.StatusCode() == fasthttp.StatusNotFound) {
if options.TryIndexPages {
// copy the options struct & try if an index page exists
optionsForIndexPages := *options
optionsForIndexPages.TryIndexPages = false
optionsForIndexPages.AppendTrailingSlash = true
for _, indexPage := range upstreamIndexPages {
if optionsForIndexPages.Upstream(ctx, targetOwner, targetRepo, targetBranch, strings.TrimSuffix(targetPath, "/")+"/"+indexPage, giteaRoot, giteaApiToken, branchTimestampCache, fileResponseCache) {
_ = fileResponseCache.Set(uri+"?timestamp="+strconv.FormatInt(options.BranchTimestamp.Unix(), 10), fileResponse{
exists: false,
}, fileCacheTimeout)
return true
}
}
// compatibility fix for GitHub Pages (/example → /example.html)
optionsForIndexPages.AppendTrailingSlash = false
optionsForIndexPages.RedirectIfExists = string(ctx.Request.URI().Path()) + ".html"
if optionsForIndexPages.Upstream(ctx, targetOwner, targetRepo, targetBranch, targetPath+".html", giteaRoot, giteaApiToken, branchTimestampCache, fileResponseCache) {
_ = fileResponseCache.Set(uri+"?timestamp="+strconv.FormatInt(options.BranchTimestamp.Unix(), 10), fileResponse{
exists: false,
}, fileCacheTimeout)
return true
}
}
ctx.Response.SetStatusCode(fasthttp.StatusNotFound)
if res != nil {
// Update cache if the request is fresh
_ = fileResponseCache.Set(uri+"?timestamp="+strconv.FormatInt(options.BranchTimestamp.Unix(), 10), fileResponse{
exists: false,
}, fileCacheTimeout)
}
return false
}
if res != nil && (err != nil || res.StatusCode() != fasthttp.StatusOK) {
fmt.Printf("Couldn't fetch contents from \"%s\": %s (status code %d)\n", req.RequestURI(), err, res.StatusCode())
html.ReturnErrorPage(ctx, fasthttp.StatusInternalServerError)
return true
}
// Append trailing slash if missing (for index files), and redirect to fix filenames in general
// options.AppendTrailingSlash is only true when looking for index pages
if options.AppendTrailingSlash && !bytes.HasSuffix(ctx.Request.URI().Path(), []byte{'/'}) {
ctx.Redirect(string(ctx.Request.URI().Path())+"/", fasthttp.StatusTemporaryRedirect)
return true
}
if bytes.HasSuffix(ctx.Request.URI().Path(), []byte("/index.html")) {
ctx.Redirect(strings.TrimSuffix(string(ctx.Request.URI().Path()), "index.html"), fasthttp.StatusTemporaryRedirect)
return true
}
if options.RedirectIfExists != "" {
ctx.Redirect(options.RedirectIfExists, fasthttp.StatusTemporaryRedirect)
return true
}
log.Debug().Msg("error handling")
// Set the MIME type
mimeType := mime.TypeByExtension(path.Ext(targetPath))
mimeTypeSplit := strings.SplitN(mimeType, ";", 2)
if _, ok := options.ForbiddenMimeTypes[mimeTypeSplit[0]]; ok || mimeType == "" {
if options.DefaultMimeType != "" {
mimeType = options.DefaultMimeType
} else {
mimeType = "application/octet-stream"
}
}
ctx.Response.Header.SetContentType(mimeType)
// Everything's okay so far
ctx.Response.SetStatusCode(fasthttp.StatusOK)
ctx.Response.Header.SetLastModified(options.BranchTimestamp)
log.Debug().Msg("response preparations")
// Write the response body to the original request
var cacheBodyWriter bytes.Buffer
if res != nil {
if res.Header.ContentLength() > fileCacheSizeLimit {
err = res.BodyWriteTo(ctx.Response.BodyWriter())
} else {
// TODO: cache is half-empty if request is cancelled - does the ctx.Err() below do the trick?
err = res.BodyWriteTo(io.MultiWriter(ctx.Response.BodyWriter(), &cacheBodyWriter))
}
} else {
_, err = ctx.Write(cachedResponse.body)
}
if err != nil {
fmt.Printf("Couldn't write body for \"%s\": %s\n", req.RequestURI(), err)
html.ReturnErrorPage(ctx, fasthttp.StatusInternalServerError)
return true
}
log.Debug().Msg("response")
if res != nil && ctx.Err() == nil {
cachedResponse.exists = true
cachedResponse.mimeType = mimeType
cachedResponse.body = cacheBodyWriter.Bytes()
_ = fileResponseCache.Set(uri+"?timestamp="+strconv.FormatInt(options.BranchTimestamp.Unix(), 10), cachedResponse, fileCacheTimeout)
}
return true
}