All alarms example - storage configuration

[ricmano]

I was checking the project especially the free storage alarms and when checking all-alarms/main.tf I think line should be updated

terraform-aws-elasticsearch-cloudwatch-sns-alarms/examples/all-alarms/main.tf

Line 32 in 3ff7334

free_storage_space_threshold = var.elasticsearch_disk_size * var.elasticsearch_instance_count * 1024 * 0.20

to something like this

free storage per node

free_storage_space_threshold = var.elasticsearch_disk_size * 1024 * 0.25

free storage on cluster

free_storage_space_total_threshold = var.elasticsearch_disk_size * var.elasticsearch_instance_count * 1024 * 0.25

I've also replaced 0.20 with 0.25, in aws documentation we have "we recommend setting it to 25% of the storage space for each node.", this will trigger the alert before having any real problem

Does this make sense? Can I create a pull request with these changes?

[dubiety]

@ricmano I think AWS updated the recommendation. PR is welcome!