Compress user_data using gzip to avoid to exceed the hard limit (32KB) (#9)

* Compress user_data using gzip to avoid to exceed the hard limit (32KB)

* Fix a lint error

* Extract a function compressing bytes to the cloud package

Co-authored-by: Wonkun Kim <[email protected]>

Author: wongni

controllers/cloudstackmachine_controller.go

@@ -167,7 +167,14 @@ func (r *CloudStackMachineReconciler) reconcile(
 	if !ok {
 		return ctrl.Result{}, errors.New("Bootstrap secret data not ok.")
 	}
-	userData := base64.StdEncoding.EncodeToString(value)
+
+	compressedValue, err := cloud.CompressData(value)
+	if err != nil {
+		log.Error(err, "Failed to compress userData")
+		return ctrl.Result{}, err
+	}
+
+	userData := base64.StdEncoding.EncodeToString(compressedValue)
 
 	// Create VM (or Fetch if present). Will set ready to true.
 	if err := r.CS.GetOrCreateVMInstance(csMachine, machine, csCluster, userData); err == nil {

pkg/cloud/helpers.go

@@ -16,10 +16,25 @@ limitations under the License.
 
 package cloud
 
+import (
+	"bytes"
+	"compress/gzip"
+)
+
 type set func(string)
 
 func setIfNotEmpty(str string, setFn set) {
 	if str != "" {
 		setFn(str)
 	}
 }
+
+func CompressData(data []byte) ([]byte, error) {
+	buf := &bytes.Buffer{}
+	gzipWriter := gzip.NewWriter(buf)
+	defer gzipWriter.Close()
+	if _, err := gzipWriter.Write(data); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}