Ensured volume mounts are sorted consistently (#300)

Author: chatton

pkg/util/merge/merge.go

@@ -2,6 +2,7 @@ package merge
 
 import (
 	"sort"
+	"strings"
 
 	"github.com/mongodb/mongodb-kubernetes-operator/pkg/util/contains"
 	corev1 "k8s.io/api/core/v1"
@@ -430,16 +431,21 @@ func VolumeMounts(original, override []corev1.VolumeMount) []corev1.VolumeMount
 	}
 
 	sort.SliceStable(mergedMounts, func(i, j int) bool {
-		return mergedMounts[i].Name < mergedMounts[j].Name
+		return volumeMountToString(mergedMounts[i]) < volumeMountToString(mergedMounts[j])
 	})
 
 	return mergedMounts
 }
 
+// volumeMountToString returns a string consisting of all components of the given VolumeMount.
+func volumeMountToString(v corev1.VolumeMount) string {
+	return strings.Join([]string{v.Name, v.MountPath, v.SubPath}, "_")
+}
+
 func createVolumeMountMap(mounts []corev1.VolumeMount) map[string]corev1.VolumeMount {
 	m := make(map[string]corev1.VolumeMount)
 	for _, v := range mounts {
-		m[v.Name] = v
+		m[volumeMountToString(v)] = v
 	}
 	return m
 }

pkg/util/merge/merge_test.go

@@ -239,7 +239,7 @@ func TestMergeContainer(t *testing.T) {
 
 		t.Run("Volume Mounts are overridden", func(t *testing.T) {
 			volumeMounts := mergedContainer.VolumeMounts
-			assert.Len(t, volumeMounts, 2)
+			assert.Len(t, volumeMounts, 3, "volume mounts can have the same name, the uniqueness is the combination of name, path and subpath")
 			t.Run("First VolumeMount is still present", func(t *testing.T) {
 				vm0 := volumeMounts[0]
 				assert.Equal(t, "volume-mount-0", vm0.Name)
@@ -249,12 +249,9 @@ func TestMergeContainer(t *testing.T) {
 				assert.Equal(t, "original-sub-path-expr", vm0.SubPathExpr)
 			})
 			t.Run("Second VolumeMount has merged values", func(t *testing.T) {
-				vm1 := volumeMounts[1]
-				assert.Equal(t, "volume-mount-1", vm1.Name)
-				assert.True(t, vm1.ReadOnly)
-				assert.Equal(t, "override-mount-path-1", vm1.MountPath)
-				assert.Equal(t, "override-sub-path-1", vm1.SubPath)
-				assert.Equal(t, "override-sub-path-expr-1", vm1.SubPathExpr)
+				assert.Equal(t, volumeMounts[0], defaultContainer.VolumeMounts[0])
+				assert.Equal(t, volumeMounts[1], defaultContainer.VolumeMounts[1])
+				assert.Equal(t, volumeMounts[2], overrideContainer.VolumeMounts[0])
 			})
 		})
 	})
@@ -588,20 +585,6 @@ func TestMergeVolumeAddVolume(t *testing.T) {
 	assert.Equal(t, corev1.EmptyDirVolumeSource{}, *volume1.EmptyDir)
 }
 
-func TestMergeVolumeMounts(t *testing.T) {
-	vol0 := corev1.VolumeMount{Name: "container-0.volume-mount-0"}
-	vol1 := corev1.VolumeMount{Name: "another-mount"}
-	volumeMounts := []corev1.VolumeMount{vol1, vol0}
-
-	mergedVolumeMounts := VolumeMounts(nil, volumeMounts)
-	assert.Equal(t, []corev1.VolumeMount{vol1, vol0}, mergedVolumeMounts)
-
-	vol2 := vol1
-	vol2.MountPath = "/somewhere"
-	mergedVolumeMounts = VolumeMounts([]corev1.VolumeMount{vol2}, []corev1.VolumeMount{vol0, vol1})
-	assert.Equal(t, []corev1.VolumeMount{vol2, vol0}, mergedVolumeMounts)
-}
-
 func TestMergeHostAliases(t *testing.T) {
 	ha0 := []corev1.HostAlias{
 		{