feat: simple caching proxy

.github/workflows/build-publish.yaml

@@ -0,0 +1,40 @@
+name: Build and Publish
+
+on:
+  push:
+
+permissions:
+  packages: write
+  contents: read
+
+jobs:
+  build-and-push-docker-image:
+    name: Build Docker image and push
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 'stable'
+
+      - name: Setup ko
+        uses: ko-build/[email protected]
+
+      - name: Login to Github Packages
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build containers
+        run: |
+          ko build --bare --sbom=none -t latest .
+        env:
+          KO_DOCKER_REPO: ghcr.io/syncthing/apt-web

go.mod

@@ -0,0 +1,5 @@
+module github.com/syncthing/apt-web
+
+go 1.23.2
+
+require github.com/meerkat-dashboard/meerkat v0.0.0-20240605084813-bc196007bb0c

go.sum

@@ -0,0 +1,2 @@
+github.com/meerkat-dashboard/meerkat v0.0.0-20240605084813-bc196007bb0c h1:jwuFa8OpeTeXT3EOq5IsiTiYKlaOU4isntQlDbZkBp8=
+github.com/meerkat-dashboard/meerkat v0.0.0-20240605084813-bc196007bb0c/go.mod h1:2qaHfLheTyaCMPpcjl/hUmRPdByJrZWQAAEn1ClllTA=

main.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"cmp"
+	"embed"
+	"io/fs"
+	"log/slog"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"os"
+	"path"
+	"time"
+
+	cacheProxy "github.com/meerkat-dashboard/meerkat/proxy"
+)
+
+//go:embed site
+var siteFS embed.FS
+
+var (
+	listenAddr = cmp.Or(os.Getenv("LISTEN_ADDRESS"), ":8080")
+	distsHost  = cmp.Or(os.Getenv("DISTS_HOST"), "https://syncthing-apt.s3.fr-par.scw.cloud")
+)
+
+func main() {
+	subFS, _ := fs.Sub(fs.FS(siteFS), "site")
+	site := http.FS(subFS)
+	http.Handle("/", http.FileServer(site))
+
+	proxy, err := newCachingProxy(distsHost, 5*time.Minute)
+	if err != nil {
+		slog.Error("failed to construct proxy", "error", err)
+		os.Exit(2)
+	}
+	filtered := validateFilename(proxy, []string{
+		"InRelease",
+		"InRelease.gz",
+		"Release",
+		"Release.gz",
+		"Release.gpg",
+		"Release.gpg.gz",
+		"Packages",
+		"Packages.gz",
+		"*.deb",
+	})
+	http.Handle("/dists/", filtered)
+
+	if err := http.ListenAndServe(listenAddr, nil); err != nil {
+		slog.Error("failed to listen", "error", err)
+	}
+}
+
+func validateFilename(next http.Handler, names []string) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		name := path.Base(req.URL.Path)
+		for _, valid := range names {
+			if ok, _ := path.Match(valid, name); ok {
+				next.ServeHTTP(w, req)
+				return
+			}
+		}
+		http.NotFound(w, req)
+	})
+}
+
+func newCachingProxy(next string, cacheTime time.Duration) (http.Handler, error) {
+	remote, err := url.Parse(next)
+	if err != nil {
+		return nil, err
+	}
+	rev := &httputil.ReverseProxy{
+		Rewrite: func(r *httputil.ProxyRequest) {
+			r.SetURL(remote)
+		},
+	}
+	cp := &cacheProxy.Proxy{}
+	cp.Next = rev
+	rev.ModifyResponse = cp.StoreOKResponse(cacheTime)
+
+	return cp, nil
+}