[k8s] Fix panic in WaitUntilDeploymentAvailable

The `func (err DeploymentNotAvailable) Error()` method should not assume
that `Status.Conditions[0]` is always valid for the Deployment.

Fixes #1329

Signed-off-by: Antonin Bas <abas@vmware.com>

modules/k8s/deployment.go

@@ -98,13 +98,16 @@ func WaitUntilDeploymentAvailableE(
 
 // IsDeploymentAvailable returns true if all pods within the deployment are ready and started
 func IsDeploymentAvailable(deploy *appsv1.Deployment) bool {
-	for _, dc := range deploy.Status.Conditions {
-		if dc.Type == appsv1.DeploymentProgressing &&
-			dc.Status == v1.ConditionTrue &&
-			dc.Reason == "NewReplicaSetAvailable" {
-			return true
+	dc := getDeploymentCondition(deploy, appsv1.DeploymentProgressing)
+	return dc != nil && dc.Status == v1.ConditionTrue && dc.Reason == "NewReplicaSetAvailable"
+}
+
+func getDeploymentCondition(deploy *appsv1.Deployment, cType appsv1.DeploymentConditionType) *appsv1.DeploymentCondition {
+	for idx := range deploy.Status.Conditions {
+		dc := &deploy.Status.Conditions[idx]
+		if dc.Type == cType {
+			return dc
 		}
 	}
-
-	return false
+	return nil
 }

modules/k8s/errors.go

@@ -69,11 +69,21 @@ type DeploymentNotAvailable struct {
 
 // Error is a simple function to return a formatted error message as a string
 func (err DeploymentNotAvailable) Error() string {
+	dc := getDeploymentCondition(err.deploy, appsv1.DeploymentProgressing)
+	if dc == nil {
+		return fmt.Sprintf(
+			"Deployment %s is not available, missing '%s' condition",
+			err.deploy.Name,
+			appsv1.DeploymentProgressing,
+		)
+	}
 	return fmt.Sprintf(
-		"Deployment %s is not available, reason: %s, message: %s",
+		"Deployment %s is not available as '%s' condition indicates that the Deployment is not complete, status: %v, reason: %s, message: %s",
 		err.deploy.Name,
-		err.deploy.Status.Conditions[0].Reason,
-		err.deploy.Status.Conditions[0].Message,
+		appsv1.DeploymentProgressing,
+		dc.Status,
+		dc.Reason,
+		dc.Message,
 	)
 }