Take credentials from the environment

By default, we strip the values so we are overwriting but if the user
specifies the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY in their
AWS_ENVAR_ALLOWLIST then they can read these from the environment

Author: simonrw

src/index.js

@@ -52,6 +52,10 @@ const configureEnvironment = (env, allowListStr) => {
     }
   });
 
+  // set credentials if not set from the environment
+  env.AWS_ACCESS_KEY_ID = env.AWS_ACCESS_KEY_ID || "test";
+  env.AWS_SECRET_ACCESS_KEY = env.AWS_SECRET_ACCESS_KEY || "test";
+
   // Explicitly set AWS_ENDPOINT_URL* to configure network access to LocalStack
   // This _must_ use localhost.localstack.cloud as we require valid subdomains of these paths to
   // resolve. Unfortunately though `curl` seems to support subdomains of localhost, the CDK does not.