From b84bb43a074713127598877c33e3e22769c3a0bd Mon Sep 17 00:00:00 2001
From: Spike Curtis <spike@coder.com>
Date: Fri, 6 Feb 2026 11:28:08 +0400
Subject: [PATCH] feat: add standard encodings to binary cache (#21921)

fixes: https://github.com/coder/internal/issues/1300

Adds brotli and zstd compression to the binary cache. Also refactors coderd's streaming encoding middleware to use the same standard set of compression algorithms, so we have them in one place.
---
 coderd/coderd.go | 19 +++++++------------
 site/bin.go      | 20 +++++++++++++++++++-
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/coderd/coderd.go b/coderd/coderd.go
index 004e40815b..5e39c302c7 100644
--- a/coderd/coderd.go
+++ b/coderd/coderd.go
@@ -21,11 +21,9 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/andybalholm/brotli"
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
 	"github.com/google/uuid"
-	"github.com/klauspost/compress/zstd"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -1972,16 +1970,13 @@ func compressHandler(h http.Handler) http.Handler {
 		"application/*",
 		"image/*",
 	)
-	cmp.SetEncoder("br", func(w io.Writer, level int) io.Writer {
-		return brotli.NewWriterLevel(w, level)
-	})
-	cmp.SetEncoder("zstd", func(w io.Writer, level int) io.Writer {
-		zw, err := zstd.NewWriter(w, zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(level)))
-		if err != nil {
-			panic("invalid zstd compressor: " + err.Error())
-		}
-		return zw
-	})
+	for encoding := range site.StandardEncoders {
+		writeCloserFn := site.StandardEncoders[encoding]
+		cmp.SetEncoder(encoding, func(w io.Writer, level int) io.Writer {
+			writeCloser := writeCloserFn(w, level)
+			return writeCloser
+		})
+	}
 
 	return cmp.Handler(h)
 }
diff --git a/site/bin.go b/site/bin.go
index 712c5ea7bf..6b220d7f2b 100644
--- a/site/bin.go
+++ b/site/bin.go
@@ -17,6 +17,7 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/andybalholm/brotli"
 	"github.com/klauspost/compress/zstd"
 	"golang.org/x/sync/errgroup"
 	"golang.org/x/sync/singleflight"
@@ -35,6 +36,19 @@ type binHandler struct {
 	handler       http.Handler
 }
 
+var StandardEncoders = map[string]func(w io.Writer, level int) io.WriteCloser{
+	"br": func(w io.Writer, level int) io.WriteCloser {
+		return brotli.NewWriterLevel(w, level)
+	},
+	"zstd": func(w io.Writer, level int) io.WriteCloser {
+		zw, err := zstd.NewWriter(w, zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(level)))
+		if err != nil {
+			panic("invalid zstd compressor: " + err.Error())
+		}
+		return zw
+	},
+}
+
 func (h *binHandler) ServeHTTP(rw http.ResponseWriter, r *http.Request) {
 	if !strings.HasPrefix(r.URL.Path, "/bin/") {
 		rw.WriteHeader(http.StatusNotFound)
@@ -120,7 +134,11 @@ func newBinHandler(options *Options) (*binHandler, error) {
 		metadataCache: newBinMetadataCache(binFS, binHashes),
 	}
 	if compressedCacheDir != "" {
-		h.handler = cachecompress.NewCompressor(options.Logger, CompressionLevel, compressedCacheDir, binFS)
+		cmp := cachecompress.NewCompressor(options.Logger, CompressionLevel, compressedCacheDir, binFS)
+		for encoding, fn := range StandardEncoders {
+			cmp.SetEncoder(encoding, fn)
+		}
+		h.handler = cmp
 	} else {
 		h.handler = http.FileServer(binFS)
 	}