1 A config change trigger causes a new deployment to be created any time the replication controller template changes. 

2 An image change trigger causes a new deployment to be created each time a new version of the backing image is available in the named image stream. 

3 The default Rolling  strategy makes a downtime-free transition between deployments. 

## 3.1.3. Deployments 

Kubernetes provides a first-class, native API object type in OpenShift Container Platform called Deployment . Deployment  objects serve as a descendant of the OpenShift Container Platform-specific DeploymentConfig  object. 

Like DeploymentConfig  objects, Deployment  objects describe the desired state of a particular component of an application as a pod template. Deployments create replica sets, which orchestrate pod lifecycles. 

For example, the following deployment definition creates a replica set to bring up one hello-openshift pod: 

## Deployment definition 

apiVersion: apps/v1 kind: Deployment metadata: name: hello-openshift spec: replicas: 1 selector: matchLabels: app: hello-openshift template: metadata: labels: app: hello-openshift spec: containers: - name: hello-openshift image: openshift/hello-openshift:latest ports: - containerPort: 80 

## 3.1.4. Comparing Deployment and DeploymentConfig objects 

Both Kubernetes Deployment  objects and OpenShift Container Platform-provided DeploymentConfig  objects are supported in OpenShift Container Platform; however, it is recommended to use Deployment  objects unless you need a specific feature or behavior provided by DeploymentConfig  objects. 

The following sections go into more detail on the differences between the two object types to further help you decide which type to use. 

## 3.1.4.1. Design 

