diff --git a/docs/user-guide/deployments.md b/docs/user-guide/deployments.md index a1a45fa507..6b7f0e6221 100644 --- a/docs/user-guide/deployments.md +++ b/docs/user-guide/deployments.md @@ -7,9 +7,9 @@ ## What is a _Deployment_? A _Deployment_ provides declarative updates for Pods and ReplicaSets. -Users describe the desired state in a Deployment object, and the deployment -controller changes the actual state to the desired state at a controlled rate. -Users can define Deployments to create new resources, or replace existing ones +You only need to describe the desired state in a Deployment object, and the deployment +controller will change the actual state to the desired state at a controlled rate for you. +You can define Deployments to create new resources, or replace existing ones by new ones. A typical use case is: @@ -181,12 +181,12 @@ template does not match `.spec.template` are scaled down. Eventually, the new replica set will be scaled to `.spec.replicas` and all old replica sets will be scaled to 0. -If the user updates a Deployment while an existing deployment is in progress, +If you update a Deployment while an existing deployment is in progress, the Deployment will create a new replica set as per the update and start scaling that up, and will roll the replica set that it was scaling up previously -- it will add it to its list of old replica sets and will start scaling it down. -For example, suppose the user creates a Deployment to create 5 replicas of `nginx:1.7.9`, +For example, suppose you create a Deployment to create 5 replicas of `nginx:1.7.9`, but then updates the Deployment to create 5 replicas of `nginx:1.9.1`, when only 3 replicas of `nginx:1.7.9` had been created. In that case, Deployment will immediately start killing the 3 `nginx:1.7.9` pods that it had created, and will start creating @@ -195,7 +195,7 @@ before changing course. ## Rolling Back a Deployment -Sometimes we may want to rollback a Deployment; for example, when the previous Deployment is crash looping. +Sometimes we may want to rollback a Deployment; for example, when the Deployment is not stable, such as crash looping. Suppose that we made a typo while updating the Deployment, by putting the image name as `nginx:1.91` instead of `nginx:1.9.1`: @@ -214,7 +214,7 @@ nginx-deployment-2035384211 0 0 36s nginx-deployment-3066724191 2 2 6s ``` -Looking at the pods created, you will see that the 2 pods created by new replica set are crash looping. +Looking at the pods created, you will see that the 2 pods created by new replica set are stuck in an image pull loop. ```console $ kubectl get pods @@ -415,7 +415,7 @@ All existing pods are killed before new ones are created when The Deployment updates pods in a [rolling update](/docs/user-guide/update-demo/) fashion when `.spec.strategy.type==RollingUpdate`. -Users can specify `maxUnavailable` and `maxSurge` to control +You can specify `maxUnavailable` and `maxSurge` to control the rolling update process. ##### Max Unavailable