A Deployment enters various states during its lifecycle. It can be [progressing](#progressing-deployment) while rolling out a new ReplicaSet,

it can be [complete](#complete-deployment), or it can [fail to progress](#failed-deployment).

Kubernetes marks a Deployment as _progressing_ when one of the following tasks is performed:

* The Deployment is in the process of creating a new ReplicaSet.

* The Deployment is scaling up an existing ReplicaSet.

* The Deployment is scaling down an existing ReplicaSet.

You can monitor the progress for a Deployment by using `kubectl rollout status`.

Kubernetes marks a Deployment as _complete_ when it has the following characteristics:

* The Deployment has minimum availability. Minimum availability means that the Deployment's number of available replicas

equals or exceeds the number required by the Deployment strategy.

* All of the replicas associated with the Deployment have been updated to the latest version you've specified, meaning any

updates you've requested have been completed.

You can check if a Deployment has completed by using `kubectl rollout status`. If the rollout completed successfully, `kubectl rollout status` returns a zero exit code.

Your Deployment may get stuck trying to deploy its newest ReplicaSet without ever completing. This can occur due to some of the following factors:

* Insufficient quota

* Readiness probe failures

* Image pull errors

* Insufficient permissions

* Limit ranges

* Application runtime misconfiguration

One way you can detect this condition is to specify specify a deadline parameter in your Deployment spec: ([`spec.progressDeadlineSeconds`](#progress-deadline-seconds)). `spec.progressDeadlineSeconds` denotes the number of seconds the Deployment controller waits before indicating (via the Deployment status) that the Deployment progress has stalled.

The following `kubectl` command sets the spec with `progressDeadlineSeconds` to make the controller report lack of progress for a Deployment after 10 minutes:

$ kubectl patch deployment/nginx-deployment -p '{"spec":{"progressDeadlineSeconds":600}}'

"nginx-deployment" patched

Once the deadline has been exceeded, the Deployment controller adds a DeploymentCondition with the following attributes to

the Deployment's `status.conditions`:

* Type=Progressing

* Status=False

* Reason=ProgressDeadlineExceeded

See the [Kubernetes API conventions](https://github.com/kubernetes/kubernetes/blob/{{page.githubbranch}}/docs/devel/api-conventions.md#typical-status-properties) for more information on status conditions.

Note that in version 1.5, Kubernetes will take no action on a stalled Deployment other than to report a status condition with

`Reason=ProgressDeadlineExceeded`.

**Note:** If you pause a Deployment, Kubernetes does not check progress against your specified deadline. You can safely pause a Deployment in the middle of a rollout and resume without triggering a the condition for exceeding the deadline.

You may experience transient errors with your Deployments, either due to a low timeout that you have set or due to any other kind

of error that can be treated as transient. For example, let's suppose you have insufficient quota. If you describe the Deployment

you will notice the following section:

If you run `kubectl get deployment nginx-deployment -o yaml`, the Deployement status might look like this:

Eventually, once the Deployment progress deadline is exceeded, Kubernetes updates the status and the reason for the Progressing condition:

You can address an issue of insufficient quota by scaling down your Deployment, by scaling down other controllers you may be running,

or by increasing quota in your namespace. If you satisfy the quota conditions and the Deployment controller then completes the Deployment

rollout, you'll see the Deployment's status update with a successful condition (`Status=True` and `Reason=NewReplicaSetAvailable`).

`Type=Available` with `Status=True` means that your Deployment has minimum availability. Minimum availability is dictated

by the parameters specified in the deployment strategy. `Type=Progressing` with `Status=True` means that your Deployment

is either in the middle of a rollout and it is progressing or that it has successfully completed its progress and the minimum

required new replicas are available (see the Reason of the condition for the particulars - in our case

`Reason=NewReplicaSetAvailable` means that the Deployment is complete).

You can check if a Deployment has failed to progress by using `kubectl rollout status`. `kubectl rollout status` returns a non-zero exit code if the Deployment has exceeded the progression deadline.

All actions that apply to a complete Deployment also apply to a failed Deployment. You can scale it up/down, roll back

to a previous revision, or even pause it if you need to apply multiple tweaks in the Deployment pod template.

`.spec.progressDeadlineSeconds` is an optional field that specifies the number of seconds you want

to wait for your Deployment to progress before the system reports back that the Deployment has

[failed progressing](#failed-deployment) - surfaced as a condition with `Type=Progressing`, `Status=False`.

and `Reason=ProgressDeadlineExceeded` in the status of the resource. The deployment controller will keep

retrying the Deployment. In the future, once automatic rollback will be implemented, the deployment

controller will roll back a Deployment as soon as it observes such a condition.

If specified, this field needs to be greater than `.spec.minReadySeconds`.