KMS: update README.md (GoogleCloudPlatform#1776)

daniel-sanche · web-flow · commit 66ead41e571e · 2019-12-06T14:00:56.000-08:00
updated kms README.md
diff --git a/kms/README.md b/kms/README.md
@@ -9,6 +9,22 @@ cloud services the same way you do on-premise. You can generate, use, rotate and
 destroy AES-256 encryption keys. These sample Java applications demonstrate
 how to access the KMS API using the Google Java API Client Libraries.
 
+## Prerequisites
+
+### Enable the API
+
+You must [enable the Google Cloud KMS API](https://console.cloud.google.com/flows/enableapi?apiid=cloudkms.googleapis.com) for your project in order to use these samples
+
+### Set Environment Variables
+
+You must set your project ID in order to run the tests
+
+`GOOGLE_CLOUD_PROJECT=<your-project-id-here>`
+
+### Grant Permissions
+
+You must ensure that the [user account or service account](https://cloud.google.com/iam/docs/service-accounts#differences_between_a_service_account_and_a_user_account) you used to authorize your gcloud session has the proper permissions to edit KMS resources for your project. More information can be found in the [Google KMS Docs](https://cloud.google.com/kms/docs/reference/permissions-and-roles)
+
 ## Quickstart
 
 Install [Maven](http://maven.apache.org/).
