adding log publishing options

[rmkbow]

https://github.com/terraform-community-modules/tf_aws_elasticsearch/issues/20

but conflicts with https://github.com/terraform-community-modules/tf_aws_elasticsearch/pull/15/files as we're both trying to implement the same thing

whichever makes more sense design/compatibility wise

[rmkbow]

pause for now, seems to throw errors if the user defined list of maps contains variables: example:

locals {
  log_publishing_options = [
    {
      cloudwatch_log_group_arn = "arn:aws:logs:${var.region}:${local.account_id}:log-group:/aws/aes/domains/${var.service}-${var.cluster}-${local.short_stage}"
      log_type = "INDEX_SLOW_LOGS"
    },
    {
      cloudwatch_log_group_arn = "arn:aws:logs:${var.region}:${local.account_id}:log-group:/aws/aes/domains/${var.service}-${var.cluster}-${local.short_stage}"
      log_type = "ES_APPLICATION_LOGS"
    },
    {
      cloudwatch_log_group_arn = "arn:aws:logs:${var.region}:${local.account_id}:log-group:/aws/aes/domains/${var.service}-${var.cluster}-${local.short_stage}"
      log_type = "SEARCH_SLOW_LOGS"
    }
  ]
}

Error: module.elasticsearch.aws_elasticsearch_domain.es: "log_publishing_options.0.cloudwatch_log_group_arn": required field is not set
Error: module.elasticsearch.aws_elasticsearch_domain.es: "log_publishing_options.0.log_type": required field is not set
Error: module.elasticsearch.aws_elasticsearch_domain.es_vpc: "log_publishing_options.0.cloudwatch_log_group_arn": required field is not set
Error: module.elasticsearch.aws_elasticsearch_domain.es_vpc: "log_publishing_options.0.log_type": required field is not set

whereas if the ARN is strictly text then it succeeds

[antonbabenko]

Thanks @rmkbow for this PR.

This feature is available in v0.7.0 which has been just released.

As you've noted there is no way to use computed values in maps, so cloudwatch_log_group_arn has to be known and specified. There is no easy workaround in Terraform 0.11.