You could create any scripts which can do the installation locally and add call to it into ec2 user data section. We have done it with ansible rower callbacks and also simple script which get all up to date scripts and configurations from S3 bucket. Personally I like to use those ansible scripts to do actual work.
If you haven’t yet Your own scripts I think that you could use even use those Splunk’s ansible scripts from GitHub.
r. Ismo
