Embed web assets into the Go binary

Serve /static from embedded assets when no static path override is configured, add static route coverage, and update Docker/docs to reflect embedded-by-default behavior.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Dockerfile

@@ -17,9 +17,6 @@ RUN apk add --no-cache ca-certificates docker-cli
 
 WORKDIR /app
 COPY --from=builder /out/webterm /usr/local/bin/webterm
-COPY go/webterm/static /app/static
-
-ENV WEBTERM_STATIC_PATH=/app/static
 
 EXPOSE 8080
 

README.md

@@ -120,5 +120,5 @@ docker build -t webterm .
 docker run -v /var/run/docker.sock:/var/run/docker.sock -p 8080:8080 webterm --docker-watch
 ```
 
-The image sets `WEBTERM_STATIC_PATH=/app/static` and serves assets from `go/webterm/static`.
+Web assets are embedded in the Go binary by default (you can still override with `WEBTERM_STATIC_PATH`).
 The Dockerfile uses a minimal Alpine runtime stage and only installs `ca-certificates` plus `docker-cli`.

docs/ARCHITECTURE.md

@@ -48,6 +48,7 @@ The server resolves static files from:
 
 1. `WEBTERM_STATIC_PATH` (if set)
 2. local repository-relative fallbacks rooted at `go/webterm/static`
+3. embedded assets bundled into the Go binary
 
 ## Docker integration
 

go/webterm/assets_embed.go

@@ -0,0 +1,18 @@
+package webterm
+
+import (
+	"embed"
+	"io/fs"
+	"net/http"
+)
+
+//go:embed static static/* static/js/* static/icons/*
+var embeddedStaticAssets embed.FS
+
+func embeddedStaticFS() (http.FileSystem, bool) {
+	sub, err := fs.Sub(embeddedStaticAssets, "static")
+	if err != nil {
+		return nil, false
+	}
+	return http.FS(sub), true
+}

go/webterm/server.go

@@ -1466,6 +1466,8 @@ func (s *LocalServer) Handler() http.Handler {
 	mux.HandleFunc("/", s.handleRoot)
 	if strings.TrimSpace(s.staticPath) != "" {
 		mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir(s.staticPath))))
+	} else if staticFS, ok := embeddedStaticFS(); ok {
+		mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(staticFS)))
 	}
 	return s.loggingMiddleware(s.gzipMiddleware(mux))
 }

go/webterm/server_test.go

@@ -221,6 +221,15 @@ func TestRootTerminalPageAndSparklineValidation(t *testing.T) {
 		t.Fatalf("unexpected root page: %q", text)
 	}
 
+	respStatic, err := http.Get(httpServer.URL + "/static/manifest.json")
+	if err != nil {
+		t.Fatalf("static request error = %v", err)
+	}
+	_ = respStatic.Body.Close()
+	if respStatic.StatusCode != http.StatusOK {
+		t.Fatalf("expected 200 for static manifest, got %d", respStatic.StatusCode)
+	}
+
 	resp2, err := http.Get(httpServer.URL + "/cpu-sparkline.svg")
 	if err != nil {
 		t.Fatalf("sparkline request error = %v", err)