metadata for v0.1.0

- Add CHANGELOG.md with v0.1.0 entry
- Update bottlerocket-ecs-updater.yaml with a default container image

Author: samuelkarp

CHANGELOG.md

@@ -0,0 +1,21 @@
+# 0.1.0
+
+Initial release of the **Bottlerocket ECS updater** - A service to automatically manage Bottlerocket updates in an Amazon ECS cluster.
+
+The Bottlerocket ECS updater is designed to help you safely automate the routine maintenance of updating the Bottlerocket instances in your cluster.
+The updater's safety features include:
+
+* Only tasks that are part of a [service](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs_services.html) will be interrupted.
+  Container instances with non-service tasks are skipped for upgrade so no critical workloads will be automatically interrupted.
+* Only container instances in the [ACTIVE state](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/container-instance-draining.html) will be upgrade.
+  Instances that have been placed into the DRAINING state are skipped for upgrade so other maintenance or debugging can be performed without interruption.
+
+In this first release of the updater, the following considerations should be kept in mind:
+
+* Only clusters of up to 50 container instances are supported.
+  If the updater is configured to target a cluster with more than 50 instances, some instances may not be updated.
+* When configuring the provided CloudFormation template, ensure that the CloudWatch log group already exists.
+  The updater will not automatically create the log group and a missing log group will cause the updater to fail to run.
+  When creating a log group, you can configure your desired log retention settings.
+
+See the [README](README.md) for additional information.

README.md

@@ -152,6 +152,9 @@ A container instance may be skipped for update when:
   The Bottlerocket ECS Updater uses newer [`apiclient update` commands](https://github.com/bottlerocket-os/bottlerocket#update-api) that were added in version [1.0.5](https://github.com/bottlerocket-os/bottlerocket/blob/develop/CHANGELOG.md#v105-2021-01-15).
   The SSM commands will fail if your Bottlerocket OS version is less than 1.0.5.
   Instances running Bottlerocket versions less than 1.0.5 need to be manually updated.
+* _Too many instances are in the cluster._
+  The Bottlerocket ECS Updater currently supports clusters of up to 50 container instances.
+  If the updater is configured to target a cluster with more than 50 instances, some instances may not be updated.
 
 ### Why do new container instances launch with older Bottlerocket versions?
 

stacks/bottlerocket-ecs-updater.yaml

@@ -10,6 +10,7 @@ Parameters:
   UpdaterImage:
     Description: 'Bottlerocket updater container image'
     Type: String
+    Default: 'public.ecr.aws/bottlerocket/bottlerocket-ecs-updater:v0.1.0'
   LogGroupName:
     Description: 'Log group name for Bottlerocket updater logs'
     Type: String