Fix 6323: compress the bundle configMap (#6408)

When creating the bundle ConfigMap(s), compress the content using gzip.

Signed-off-by: Nahshon Unna-Tsameret <[email protected]>

Author: nunnatsa

changelog/fragments/support_configmap_compression.yaml

@@ -0,0 +1,21 @@
+# entries is a list of entries to include in
+# release notes and/or the migration guide
+entries:
+  - description: >
+      Compress the bundle content, to avoid the configMap exceed max length error.
+      The error will look like this: 
+      
+      `... ConfigMap ... is invalid: []: Too long: must have at most 1048576 bytes`.
+      
+      Fixes issue [#6323](https://github.com/operator-framework/operator-sdk/issues/6323)
+
+    # kind is one of:
+    # - addition
+    # - change
+    # - deprecation
+    # - removal
+    # - bugfix
+    kind: "bugfix"
+
+    # Is this a breaking change?
+    breaking: false

internal/olm/operator/registry/fbcindex/configMapWriter.go

@@ -0,0 +1,173 @@
+// Copyright 2023 The Operator-SDK Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fbcindex
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+const (
+	yamlSeparator    = "\n---\n"
+	gzipSuffixLength = 13
+	maxGZIPLength    = maxConfigMapSize - gzipSuffixLength
+
+	ConfigMapEncodingAnnotationKey  = "olm.contentEncoding"
+	ConfigMapEncodingAnnotationGzip = "gzip+base64"
+)
+
+/*
+This file implements the actual building of the CM list. It uses the template method design pattern to implement both
+regular string VM, and compressed binary CM.
+
+The method itself is FBCRegistryPod.getConfigMaps. This file contains the actual implementation of the writing actions,
+used by the method.
+*/
+
+type configMapWriter interface {
+	reset()
+	newConfigMap(string) *corev1.ConfigMap
+	getFilePath() string
+	isEmpty() bool
+	exceedMaxLength(cmSize int, data string) (bool, error)
+	closeCM(cm *corev1.ConfigMap) error
+	addData(data string) error
+	continueAddData(data string) error
+	writeLastFragment(cm *corev1.ConfigMap) error
+}
+
+type gzipCMWriter struct {
+	actualBuff   *bytes.Buffer
+	helperBuff   *bytes.Buffer
+	actualWriter *gzip.Writer
+	helperWriter *gzip.Writer
+	cmName       string
+	namespace    string
+}
+
+func newGZIPWriter(name, namespace string) *gzipCMWriter {
+	actualBuff := &bytes.Buffer{}
+	helperBuff := &bytes.Buffer{}
+
+	return &gzipCMWriter{
+		actualBuff:   actualBuff,
+		helperBuff:   helperBuff,
+		actualWriter: gzip.NewWriter(actualBuff),
+		helperWriter: gzip.NewWriter(helperBuff),
+		cmName:       name,
+		namespace:    namespace,
+	}
+}
+
+func (cmw *gzipCMWriter) reset() {
+	cmw.actualBuff.Reset()
+	cmw.actualWriter.Reset(cmw.actualBuff)
+	cmw.helperBuff.Reset()
+	cmw.helperWriter.Reset(cmw.helperBuff)
+}
+
+func (cmw *gzipCMWriter) newConfigMap(name string) *corev1.ConfigMap {
+	return &corev1.ConfigMap{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: corev1.SchemeGroupVersion.String(),
+			Kind:       "ConfigMap",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Namespace: cmw.namespace,
+			Name:      name,
+			Annotations: map[string]string{
+				ConfigMapEncodingAnnotationKey: ConfigMapEncodingAnnotationGzip,
+			},
+		},
+		BinaryData: map[string][]byte{},
+	}
+}
+
+func (cmw *gzipCMWriter) getFilePath() string {
+	return fmt.Sprintf("%s.yaml.gz", defaultConfigMapKey)
+}
+
+func (cmw *gzipCMWriter) isEmpty() bool {
+	return cmw.actualBuff.Len() > 0
+}
+
+func (cmw *gzipCMWriter) exceedMaxLength(cmSize int, data string) (bool, error) {
+	_, err := cmw.helperWriter.Write([]byte(data))
+	if err != nil {
+		return false, err
+	}
+
+	err = cmw.helperWriter.Flush()
+	if err != nil {
+		return false, err
+	}
+
+	return cmSize+cmw.helperBuff.Len() > maxGZIPLength, nil
+}
+
+func (cmw *gzipCMWriter) closeCM(cm *corev1.ConfigMap) error {
+	err := cmw.actualWriter.Close()
+	if err != nil {
+		return err
+	}
+
+	err = cmw.actualWriter.Flush()
+	if err != nil {
+		return err
+	}
+
+	cm.BinaryData[defaultConfigMapKey] = make([]byte, cmw.actualBuff.Len())
+	copy(cm.BinaryData[defaultConfigMapKey], cmw.actualBuff.Bytes())
+
+	cmw.reset()
+
+	return nil
+}
+
+func (cmw *gzipCMWriter) addData(data string) error {
+	dataBytes := []byte(data)
+	_, err := cmw.helperWriter.Write(dataBytes)
+	if err != nil {
+		return err
+	}
+	_, err = cmw.actualWriter.Write(dataBytes)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// continueAddData completes adding the data after starting adding it in exceedMaxLength
+func (cmw *gzipCMWriter) continueAddData(data string) error {
+	_, err := cmw.actualWriter.Write([]byte(data))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (cmw *gzipCMWriter) writeLastFragment(cm *corev1.ConfigMap) error {
+	err := cmw.actualWriter.Close()
+	if err != nil {
+		return err
+	}
+
+	cm.BinaryData[defaultConfigMapKey] = cmw.actualBuff.Bytes()
+	return nil
+}