fix(expand CRDs): Improved checks by using struct methods

Author: MatteoMori8

pkg/apis/vaultwebhook.uswitch.com/v1alpha1/types.go

@@ -37,3 +37,27 @@ type DatabaseCredentialBindingList struct {
 type Container struct {
 	Lifecycle corev1.Lifecycle `json:"lifecycle,omitempty"`
 }
+
+/*
+Check if Container.Lifecycle.PreStop is valid.
+This is to avoid mishandling incomplete inputs like the below:
+
+https://pkg.go.dev/k8s.io/api/core/v1#LifecycleHandler
+{
+
+	"Lifecycle": {
+		"PostStart": null,
+		"PreStop": {
+		"Exec": null,  # <----- Missing Command!!
+		"HTTPGet": null,
+		"TCPSocket": null
+		}
+	}
+
+}
+*/
+func (c Container) HasValidPreStop() bool {
+	return c.Lifecycle.PreStop != nil &&
+		c.Lifecycle.PreStop.Exec != nil &&
+		len(c.Lifecycle.PreStop.Exec.Command) > 0
+}

vault.go

@@ -210,9 +210,15 @@ func appendVolumeMountIfMissing(slice []corev1.VolumeMount, v corev1.VolumeMount
 // Conditionally set Lifecycle if it exists in containerSpec
 func addLifecycleHook(container corev1.Container, containerSpec v1alpha1.Container) corev1.Container {
 
+	// Check DatabaseCredentialBindingSpec.Container.Lifecycle is not empty
 	emptyLifecycle := corev1.Lifecycle{}
 	if containerSpec.Lifecycle != emptyLifecycle {
-		container.Lifecycle = &containerSpec.Lifecycle
+
+		// Check for a complete PreStop hook
+		if containerSpec.HasValidPreStop() {
+			container.Lifecycle = &containerSpec.Lifecycle
+		}
+
 	}
 	// TODO: Fix support for initcontainer's Lifecycle hooks ( Go dep to be updated )
 	// Init containers must have RestartPolicy=Always to be able to support Lifecycle hooks