fix up docs

README.md

@@ -125,12 +125,16 @@ You can add additional variables using the `--bindings=BINDINGS` option. For exa
 - `kubernetes-deploy.shopify.io/timeout-override`: Override the tool's hard timeout for one specific resource. Both full ISO8601 durations and the time portion of ISO8601 durations are valid. Value must be between 1 second and 24 hours.
   - _Example values_: 45s / 3m / 1h / PT0.25H
   - _Compatibility_: all resource types (Note: `Deployment` timeouts are based on `spec.progressDeadlineSeconds` if present, and that field has a default value as of the `apps/v1beta1` group version. Using this annotation will have no effect on `Deployment`s that time out with "Timeout reason: ProgressDeadlineExceeded".)
-- `kubernetes-deploy.shopify.io/required-rollout` (deployment): Modifies the conditions a deployment is
-   considered to be successful
-  - `maxUnavailable`: Only for `RollingUpdate deploys`. The deploy is successful when there are less
-     than `strategy.RollingUpdate.maxUnavailable` (supports both the % and fixed number) updated & ready replicas.
-  - `full`: maintain current behavior
-  - `none`: deploy is successful as soon as the new `replicaSet` is created for the deploy
+- `kubernetes-deploy.shopify.io/required-rollout`: Modifies how much of the rollout needs to finish
+before the deployment is considered successful.
+  - _Compatibility_: Deployment
+  - `full`: The deploy is successful when all pods in the new ReplicaSet are ready.
+  - `none`: The deploy is successful as soon as the new `replicaSet` is created for the deploy
+  - `maxUnavailable`: The deploy is successful when minimum availability is reached in the new ReplicaSet.
+  In other words, the number of new pods that must be ready is equal to `spec.replicas` - `strategy.RollingUpdate.maxUnavailable`
+  (converted from percentages by rounding up, if applicable). This option is only valid for deployments
+  that use the `RollingUpdate` strategy.
+
 
 ### Running tasks at the beginning of a deploy
 

lib/kubernetes-deploy/kubernetes_resource/deployment.rb

@@ -101,21 +101,19 @@ def exists?
     end
 
     def validate_definition
-      valid = super
+      super
 
       unless REQUIRED_ROLLOUT_TYPES.include?(required_rollout)
         @validation_errors << "#{REQUIRED_ROLLOUT_ANNOTATION}:#{required_rollout} is invalid "\
         "Acceptable options: #{REQUIRED_ROLLOUT_TYPES.join(',')}"
-        valid = false
       end
 
-      if required_rollout == 'maxUnavailable' && @definition.dig('spec', 'strategy') == 'recreate'
+      if required_rollout.downcase == 'maxunavailable' && @definition.dig('spec', 'strategy').downcase == 'recreate'
         @validation_errors << "#{REQUIRED_ROLLOUT_ANNOTATION}:#{required_rollout} is invalid "\
         "with strategy 'rollingUpdate'"
-        valid = false
       end
 
-      valid
+      @validation_errors.empty?
     end
 
     private