Implement domain handling logic

Still lots of performance optimization required!
This commit is contained in:
Moritz Marquardt 2021-07-09 01:16:00 +02:00
parent 13b386d442
commit 675e56ee98
No known key found for this signature in database
GPG key ID: D5788327BEE388B6
2 changed files with 133 additions and 12 deletions

View file

@ -1,15 +1,94 @@
package main
import "github.com/valyala/fasthttp"
import (
"github.com/OrlovEvgeny/go-mcache"
"github.com/valyala/fasthttp"
"net"
"strings"
"time"
)
// getTargetFromDNS searches for CNAME entries on the request domain, optionally with a "www." prefix, and checks if
// the domain is included in the repository's "domains.txt" file. If everything is fine, it returns the target data.
// TODO: use TXT records with A/AAAA/ALIAS
func getTargetFromDNS(ctx *fasthttp.RequestCtx) (targetOwner, targetRepo, targetBranch, targetPath string) {
// TODO: read CNAME record for host and "www.{host}" to get those values
// TODO: check domains.txt
// DnsLookupCacheTimeout specifies the timeout for the DNS lookup cache.
var DnsLookupCacheTimeout = 15*time.Minute
// dnsLookupCache stores DNS lookups for custom domains
var dnsLookupCache = mcache.New()
// getTargetFromDNS searches for CNAME or TXT entries on the request domain ending with MainDomainSuffix, and checks if
// the domain equals the repository's ".canonical-domain" file. If everything is fine, it returns the target data.
func getTargetFromDNS(domain string) (targetOwner, targetRepo, targetBranch string) {
// Get CNAME or TXT
var cname string
var err error
if cachedName, ok := dnsLookupCache.Get(domain); ok {
cname = cachedName.(string)
} else {
cname, err = net.LookupCNAME(domain)
cname = strings.TrimSuffix(cname, ".")
if err != nil || !strings.HasSuffix(cname, string(MainDomainSuffix)) {
cname = ""
names, err := net.LookupTXT(domain)
if err == nil {
for _, name := range names {
name = strings.TrimSuffix(name, ".")
if strings.HasSuffix(name, string(MainDomainSuffix)) {
cname = name
break
}
}
}
}
_ = dnsLookupCache.Set(domain, cname, DnsLookupCacheTimeout)
}
if cname == "" {
return
}
cnameParts := strings.Split(strings.TrimSuffix(cname, string(MainDomainSuffix)), ".")
targetOwner = cnameParts[len(cnameParts)-1]
if len(cnameParts) > 1 {
targetRepo = cnameParts[len(cnameParts)-1]
}
if len(cnameParts) > 2 {
targetBranch = cnameParts[len(cnameParts)-2]
}
if targetRepo == "" {
targetRepo = "pages"
}
if targetBranch == "" && targetRepo != "pages" {
targetBranch = "pages"
}
// if targetBranch is still empty, the caller must find the default branch
return
}
// TODO: cache domains.txt for 15 minutes
// TODO: canonical domains - redirect to first domain if domains.txt exists, also make sure owner.codeberg.page/pages/... redirects to /...
// CanonicalDomainCacheTimeout specifies the timeout for the canonical domain cache.
var CanonicalDomainCacheTimeout = 15*time.Minute
// canonicalDomainCache stores canonical domains
var canonicalDomainCache = mcache.New()
// checkCanonicalDomain returns the canonical domain specified in the repo (using the file `.canonical-domain`).
func checkCanonicalDomain(targetOwner, targetRepo, targetBranch string) (canonicalDomain string) {
// Check if the canonical domain matches
req := fasthttp.AcquireRequest()
req.SetRequestURI(string(GiteaRoot) + "/api/v1/repos/" + targetOwner + "/" + targetRepo + "/raw/" + targetBranch + "/.canonical-domain")
res := fasthttp.AcquireResponse()
if cachedValue, ok := canonicalDomainCache.Get(string(req.RequestURI())); ok {
canonicalDomain = cachedValue.(string)
} else {
err := upstreamClient.Do(req, res)
if err == nil && res.StatusCode() == fasthttp.StatusOK {
canonicalDomain = strings.TrimSpace(string(res.Body()))
if strings.Contains(canonicalDomain, "/") {
canonicalDomain = ""
}
}
if canonicalDomain == "" {
canonicalDomain = targetOwner + string(MainDomainSuffix)
if targetRepo != "" && targetRepo != "pages" {
canonicalDomain += "/" + targetRepo
}
}
_ = canonicalDomainCache.Set(string(req.RequestURI()), canonicalDomain, CanonicalDomainCacheTimeout)
}
return
}

View file

@ -98,6 +98,19 @@ func handler(ctx *fasthttp.RequestCtx) {
// tryUpstream forwards the target request to the Gitea API, and shows an error page on failure.
var tryUpstream = func() {
// check if a canonical domain exists on a request on MainDomain
if bytes.HasSuffix(ctx.Request.Host(), MainDomainSuffix) {
canonicalDomain := checkCanonicalDomain(targetOwner, targetRepo, targetBranch)
if !strings.HasSuffix(strings.SplitN(canonicalDomain, "/", 2)[0], string(MainDomainSuffix)) {
canonicalPath := string(ctx.RequestURI())
if targetRepo != "pages" {
canonicalPath = "/" + strings.SplitN(canonicalPath, "/", 3)[2]
}
ctx.Redirect("https://" + canonicalDomain + canonicalPath, fasthttp.StatusTemporaryRedirect)
return
}
}
// Try to request the file from the Gitea API
if !upstream(ctx, targetOwner, targetRepo, targetBranch, targetPath, targetOptions) {
returnErrorPage(ctx, ctx.Response.StatusCode())
@ -151,7 +164,7 @@ func handler(ctx *fasthttp.RequestCtx) {
if len(pathElements) > 1 && strings.HasPrefix(pathElements[1], "@") {
if targetRepo == "pages" {
// example.codeberg.org/pages/@... redirects to example.codeberg.org/@...
ctx.Redirect("/" + strings.Join(pathElements[1:], "/"), fasthttp.StatusMovedPermanently)
ctx.Redirect("/" + strings.Join(pathElements[1:], "/"), fasthttp.StatusTemporaryRedirect)
return
}
@ -196,12 +209,41 @@ func handler(ctx *fasthttp.RequestCtx) {
return
} else {
// Serve pages from external domains
targetOwner, targetRepo, targetBranch, targetPath = getTargetFromDNS(ctx)
targetOwner, targetRepo, targetBranch = getTargetFromDNS(string(ctx.Request.Host()))
if targetOwner == "" {
ctx.Redirect(BrokenDNSPage, fasthttp.StatusTemporaryRedirect)
return
}
pathElements := strings.Split(string(bytes.Trim(ctx.Request.URI().Path(), "/")), "/")
canonicalLink := ""
if strings.HasPrefix(pathElements[0], "@") {
targetBranch = pathElements[0][1:]
pathElements = pathElements[1:]
canonicalLink = "/%p"
}
// Try to use the given repo on the given branch or the default branch
if tryBranch(targetRepo, targetBranch, pathElements, canonicalLink) {
canonicalDomain := checkCanonicalDomain(targetOwner, targetRepo, targetBranch)
if canonicalDomain != string(ctx.Request.Host()) {
// only redirect if
targetOwner, _, _ = getTargetFromDNS(strings.SplitN(canonicalDomain, "/", 2)[0])
if targetOwner != "" {
ctx.Redirect("https://"+canonicalDomain+string(ctx.RequestURI()), fasthttp.StatusTemporaryRedirect)
return
} else {
ctx.Redirect(BrokenDNSPage, fasthttp.StatusTemporaryRedirect)
return
}
}
tryUpstream()
return
} else {
returnErrorPage(ctx, fasthttp.StatusFailedDependency)
return
}
}
}