terraform manifests to set up nextcloud

2dos:

• refactor variables using
• switch to prepared ami-image
• add ELB
• add autoscaling group
• create security group for application rather than default

problems

• database instance still uses default security group

Short summary

It would be nice to do following:

• add detection if 'NC' is installed (check config, check 'installed' there and check database tables existance and several more checks) and run occ maintenance:install with appropriate paramereters and import settings to keep objectstore in S3. But that's not a goal to fully automate this.
• after implementation of previous option It worth re-organize manifest to begin with separate VPC which will hold all relevant resources (rds, elb and so on).
• also it worth working on ELB healthchech + image warm-up time because there's a 1-6 seconds gap in "seamless" update depending on health_check interval.

But that doesn't makes sense at the moment. later I definitely will get back to this and finish refactoring.