pages-server/server/upstream/redirects.go
video-prize-ranch 974229681f Initial redirects implementation (#148)
Adds basic support for `_redirects` files. It supports a subset of what IPFS supports: https://docs.ipfs.tech/how-to/websites-on-ipfs/redirects-and-custom-404s/

Example:
```
/redirect https://example.com/ 301
/another-redirect /page 301
/302  https://example.com/  302
/app/* /index.html 200
/articles/* /posts/:splat 301
```
301 redirect: https://video-prize-ranch.localhost.mock.directory:4430/redirect
SPA rewrite: https://video-prize-ranch.localhost.mock.directory:4430/app/path/path
Catch-all with splat: https://video-prize-ranch.localhost.mock.directory:4430/articles/path/path

Closes #46

Co-authored-by: video-prize-ranch <cb.8a3w5@simplelogin.co>
Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://codeberg.org/Codeberg/pages-server/pulls/148
Reviewed-by: 6543 <6543@obermui.de>
Co-authored-by: video-prize-ranch <video-prize-ranch@noreply.codeberg.org>
Co-committed-by: video-prize-ranch <video-prize-ranch@noreply.codeberg.org>
2023-03-30 21:36:31 +00:00

118 lines
3.4 KiB
Go

package upstream
import (
"strconv"
"strings"
"time"
"codeberg.org/codeberg/pages/server/cache"
"codeberg.org/codeberg/pages/server/context"
"codeberg.org/codeberg/pages/server/gitea"
"github.com/rs/zerolog/log"
)
type Redirect struct {
From string
To string
StatusCode int
}
// 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.SetGetKey) []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.SetGetKey) (final bool) {
if len(redirects) > 0 {
for _, redirect := range redirects {
reqUrl := ctx.Req.RequestURI
// remove repo and branch from request url
reqUrl = strings.TrimPrefix(reqUrl, "/"+o.TargetRepo)
reqUrl = strings.TrimPrefix(reqUrl, "/@"+o.TargetBranch)
// check if from url matches request url
if strings.TrimSuffix(redirect.From, "/") == strings.TrimSuffix(reqUrl, "/") {
// do rewrite if status code is 200
if redirect.StatusCode == 200 {
o.TargetPath = redirect.To
o.Upstream(ctx, giteaClient, redirectsCache)
return true
} else {
ctx.Redirect(redirect.To, redirect.StatusCode)
return true
}
}
// handle wildcard redirects
trimmedFromUrl := strings.TrimSuffix(redirect.From, "/*")
if strings.HasSuffix(redirect.From, "/*") && strings.HasPrefix(reqUrl, trimmedFromUrl) {
if strings.Contains(redirect.To, ":splat") {
splatUrl := strings.ReplaceAll(redirect.To, ":splat", strings.TrimPrefix(reqUrl, trimmedFromUrl))
// do rewrite if status code is 200
if redirect.StatusCode == 200 {
o.TargetPath = splatUrl
o.Upstream(ctx, giteaClient, redirectsCache)
return true
} else {
ctx.Redirect(splatUrl, redirect.StatusCode)
return true
}
} else {
// do rewrite if status code is 200
if redirect.StatusCode == 200 {
o.TargetPath = redirect.To
o.Upstream(ctx, giteaClient, redirectsCache)
return true
} else {
ctx.Redirect(redirect.To, redirect.StatusCode)
return true
}
}
}
}
}
return false
}