Fix panic when trying to replace placeholders

There were cases of panic when the SyncConfig has items that contain arrays
of primitive types.

Makefile

@@ -44,7 +44,7 @@ $(TESTBIN_DIR):
 integration_test: export ENVTEST_K8S_VERSION = 1.19.0
 integration_test: generate fmt vet manifests $(TESTBIN_DIR)
 	test -f ${ENVTEST_ASSETS_DIR}/setup-envtest.sh || curl -sSLo ${ENVTEST_ASSETS_DIR}/setup-envtest.sh https://raw.githubusercontent.com/kubernetes-sigs/controller-runtime/master/hack/setup-envtest.sh
-	source ${ENVTEST_ASSETS_DIR}/setup-envtest.sh; fetch_envtest_tools $(ENVTEST_ASSETS_DIR); setup_envtest_env $(ENVTEST_ASSETS_DIR); go test ./... -coverprofile cover.out -ginkgo.v
+	source ${ENVTEST_ASSETS_DIR}/setup-envtest.sh; fetch_envtest_tools $(ENVTEST_ASSETS_DIR); setup_envtest_env $(ENVTEST_ASSETS_DIR); go test -v ./... -coverprofile cover.out
 
 .PHONY: dist
 dist: generate fmt vet

controllers/syncconfig_controller_test.go

@@ -1,8 +1,3 @@
-/*
-Licensed under the Apache License, Version 2.0 (the "License");
-http://www.apache.org/licenses/LICENSE-2.0
-*/
-
 package controllers
 
 import (
@@ -114,10 +109,10 @@ var _ = Describe("SyncConfig controller", func() {
 		Expect(result).ToNot(BeNil())
 
 		By("verify that resource exist")
-		syncResult := &v1.ConfigMap{}
-		key := types.NamespacedName{Namespace: ns, Name: cm.Name}
-		Expect(k8sClient.Get(context.Background(), key, syncResult)).ToNot(HaveOccurred())
-		Expect(syncResult.Data["PROJECT_NAME"]).To(BeEquivalentTo(ns))
+		cmResult := &v1.ConfigMap{}
+		cmKey := types.NamespacedName{Namespace: ns, Name: cm.Name}
+		Expect(k8sClient.Get(context.Background(), cmKey, cmResult)).ToNot(HaveOccurred())
+		Expect(cmResult.Data["PROJECT_NAME"]).To(BeEquivalentTo(ns))
 
 		newSC := &SyncConfig{ObjectMeta: toObjectMeta(sc.Name, sc.Namespace)}
 		err = k8sClient.Get(context.Background(), toObjectKey(newSC), newSC)
@@ -233,12 +228,12 @@ var _ = Describe("SyncConfig controller", func() {
 	})
 })
 
-func toUnstructured(configMap *v1.ConfigMap) unstructured.Unstructured {
-	obj := unstructured.Unstructured{}
-	m, err := runtime.DefaultUnstructuredConverter.ToUnstructured(configMap)
+func toUnstructured(obj interface{}) unstructured.Unstructured {
+	converted := unstructured.Unstructured{}
+	m, err := runtime.DefaultUnstructuredConverter.ToUnstructured(obj)
 	Expect(err).ToNot(HaveOccurred())
-	obj.SetUnstructuredContent(m)
-	return obj
+	converted.SetUnstructuredContent(m)
+	return converted
 }
 
 func toObjectKey(config *SyncConfig) types.NamespacedName {

controllers/utils.go

@@ -1,13 +1,18 @@
 package controllers
 
 import (
+	"errors"
+	"fmt"
 	"github.com/vshn/espejo/api/v1alpha1"
 	"k8s.io/api/core/v1"
 	v12 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	ctrl "sigs.k8s.io/controller-runtime"
 	"strings"
 )
 
+var log = ctrl.Log.WithName("utils")
+
 func getLoggingKeysAndValues(unstructuredObject *unstructured.Unstructured) []interface{} {
 	return []interface{}{
 		"Object.Kind", unstructuredObject.GetKind(),
@@ -22,28 +27,61 @@ func getLoggingKeysAndValuesForSyncConfig(syncconfig *v1alpha1.SyncConfig) []int
 	}
 }
 
+// replaceProjectName recursively replaces all string occurrences that contain the ${PROJECT_NAME} as placeholder.
+// Only replaces the values of objects, does not alter the keys.
 func replaceProjectName(replacement string, m map[string]interface{}) {
 	for k, v := range m {
 		if v == nil {
 			continue
 		}
-		switch v.(type) {
-		case string:
-			s := m[k].(string)
-			m[k] = strings.ReplaceAll(s, "${PROJECT_NAME}", replacement)
-		case int64:
-		case int32:
-		case int:
-		case bool:
-			continue
-		case []interface{}:
-			for _, elem := range v.([]interface{}) {
-				replaceProjectName(replacement, elem.(map[string]interface{}))
-			}
-		case interface{}:
-			replaceProjectName(replacement, m[k].(map[string]interface{}))
+		m[k] = transcendStructure(replacement, v)
+	}
+}
+
+func transcendStructure(replacement string, v interface{}) interface{} {
+	if v == nil {
+		return nil
+	}
+	switch v.(type) {
+	case string:
+		return replacePlaceholders(replacement, v.(string))
+	case []string:
+		for i, a := range v.([]string) {
+			v.([]string)[i] = replacePlaceholders(replacement, a)
 		}
+		return v
+	case int64:
+	case []int64:
+	case int32:
+	case []int32:
+	case int:
+	case []int:
+	case bool:
+	case []bool:
+		return v
+	case map[string]interface{}:
+		for k, m := range v.(map[string]interface{}) {
+			v.(map[string]interface{})[k] = transcendStructure(replacement, m)
+		}
+		return v
+	case []map[string]interface{}:
+		for k, m := range v.([]map[string]interface{}) {
+			v.([]map[string]interface{})[k] = transcendStructure(replacement, m).(map[string]interface{})
+		}
+		return v
+	case []interface{}:
+		for i, a := range v.([]interface{}) {
+			v.([]interface{})[i] = transcendStructure(replacement, a)
+		}
+		return v
+	default:
+		log.Error(errors.New(fmt.Sprintf("unrecognized type: %s is %T", v, v)), "Cannot replace placeholders in structure")
 	}
+	return v
+}
+
+func replacePlaceholders(replacement, s string) string {
+	return strings.ReplaceAll(s, "${PROJECT_NAME}", replacement)
 }
 
 func namespaceFromString(namespace string) v1.Namespace {

controllers/utils_test.go

@@ -0,0 +1,59 @@
+package controllers
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func Test_Replacement(t *testing.T) {
+	replacement := "my-string"
+	placeholder := "${PROJECT_NAME}"
+
+	var m map[string]interface{}
+	m = map[string]interface{}{
+		"object-with-nested-objects": map[string]interface{}{
+			"object": map[string]interface{}{
+				"string-field": placeholder,
+			},
+		},
+		"slice-with-strings":     []string{placeholder},
+		"slice-with-other-types": []int{0, 1},
+		"slice-with-nested-objects": []map[string]interface{}{
+			{
+				"object": map[string]interface{}{
+					"string-field": placeholder,
+				},
+			},
+			{
+				"string-field": placeholder,
+			},
+		},
+		"slice-with-nested-slices": []interface{}{
+			[]string{placeholder},
+			map[string]interface{}{
+				"string-field": placeholder,
+				"bool-field":   true,
+			},
+			[]interface{}{
+				[]string{placeholder},
+			},
+			[]map[string]interface{}{
+				{
+					"string-field": placeholder,
+				},
+			},
+		},
+	}
+
+	replaceProjectName(replacement, m)
+
+	assert.Equal(t, replacement, m["object-with-nested-objects"].(map[string]interface{})["object"].(map[string]interface{})["string-field"])
+	assert.Equal(t, replacement, m["slice-with-strings"].([]string)[0])
+	assert.Equal(t, replacement, m["slice-with-nested-objects"].([]map[string]interface{})[0]["object"].(map[string]interface{})["string-field"])
+	assert.Equal(t, replacement, m["slice-with-nested-objects"].([]map[string]interface{})[1]["string-field"])
+	assert.Equal(t, replacement, m["slice-with-nested-slices"].([]interface{})[0].([]string)[0])
+	assert.Equal(t, replacement, m["slice-with-nested-slices"].([]interface{})[1].(map[string]interface{})["string-field"])
+	assert.Equal(t, replacement, m["slice-with-nested-slices"].([]interface{})[2].([]interface{})[0].([]string)[0])
+	assert.Equal(t, replacement, m["slice-with-nested-slices"].([]interface{})[3].([]map[string]interface{})[0]["string-field"])
+
+}

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/onsi/ginkgo v1.14.2
 	github.com/onsi/gomega v1.10.3
 	github.com/spf13/pflag v1.0.5
+	github.com/stretchr/testify v1.4.0
 	go.uber.org/zap v1.16.0
 	k8s.io/api v0.18.6
 	k8s.io/apimachinery v0.18.6