Support gzip encoding

pkg/schemaserver/writer/gzip.go

@@ -0,0 +1,52 @@
+package writer
+
+import (
+	"compress/gzip"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	"github.com/rancher/steve/pkg/schemaserver/types"
+)
+
+type GzipWriter struct {
+	types.ResponseWriter
+}
+
+func setup(apiOp *types.APIRequest) (*types.APIRequest, io.Closer) {
+	if !strings.Contains(apiOp.Request.Header.Get("Accept-Encoding"), "gzip") {
+		return apiOp, ioutil.NopCloser(nil)
+	}
+
+	apiOp.Response.Header().Set("Content-Encoding", "gzip")
+	apiOp.Response.Header().Del("Content-Length")
+
+	gz := gzip.NewWriter(apiOp.Response)
+	gzw := &gzipResponseWriter{Writer: gz, ResponseWriter: apiOp.Response}
+
+	newOp := *apiOp
+	newOp.Response = gzw
+	return &newOp, gz
+}
+
+func (g *GzipWriter) Write(apiOp *types.APIRequest, code int, obj types.APIObject) {
+	apiOp, closer := setup(apiOp)
+	defer closer.Close()
+	g.ResponseWriter.Write(apiOp, code, obj)
+}
+
+func (g *GzipWriter) WriteList(apiOp *types.APIRequest, code int, obj types.APIObjectList) {
+	apiOp, closer := setup(apiOp)
+	defer closer.Close()
+	g.ResponseWriter.WriteList(apiOp, code, obj)
+}
+
+type gzipResponseWriter struct {
+	io.Writer
+	http.ResponseWriter
+}
+
+func (g gzipResponseWriter) Write(b []byte) (int, error) {
+	return g.Writer.Write(b)
+}