Add MSC3916-compatible giphy media repo proxy

giphyproxy/main.go

@@ -0,0 +1,62 @@
+// maunium-stickerpicker - A fast and simple Matrix sticker picker widget.
+// Copyright (C) 2024 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"os"
+	"regexp"
+
+	"go.mau.fi/util/exerrors"
+	"gopkg.in/yaml.v3"
+	"maunium.net/go/mautrix/federation"
+	"maunium.net/go/mautrix/mediaproxy"
+)
+
+type Config struct {
+	mediaproxy.BasicConfig  `yaml:",inline"`
+	mediaproxy.ServerConfig `yaml:",inline"`
+}
+
+var configPath = flag.String("config", "config.yaml", "config file path")
+var generateServerKey = flag.Bool("generate-key", false, "generate a new server key and exit")
+
+var giphyIDRegex = regexp.MustCompile(`^[a-zA-Z0-9-_]+$`)
+
+func main() {
+	flag.Parse()
+	if *generateServerKey {
+		fmt.Println(federation.GenerateSigningKey().SynapseString())
+	} else {
+		cfgFile := exerrors.Must(os.ReadFile(*configPath))
+		var cfg Config
+		exerrors.PanicIfNotNil(yaml.Unmarshal(cfgFile, &cfg))
+		mp := exerrors.Must(mediaproxy.NewFromConfig(cfg.BasicConfig, getMedia))
+		exerrors.PanicIfNotNil(mp.Listen(cfg.ServerConfig))
+	}
+}
+
+func getMedia(_ context.Context, id string) (response mediaproxy.GetMediaResponse, err error) {
+	if !giphyIDRegex.MatchString(id) {
+		return nil, mediaproxy.ErrInvalidMediaIDSyntax
+	}
+	return &mediaproxy.GetMediaResponseURL{
+		URL: fmt.Sprintf("https://i.giphy.com/%s.webp", id),
+	}, nil
+}