[Bug] elasticsearch_index.alias and import regressions

[daemitus]

Regression due to #698

The alias on my existing index wants to flip the is_write_index field
Additionally, import is no longer supported.

Elasticsearch version: 8.15.1
Provider version: main/head

  # module.elastic.module.signals.elasticstack_elasticsearch_index.signals_defender will be updated in-place
  ~ resource "elasticstack_elasticsearch_index" "index" {
      - default_pipeline       = "something" -> null
        id                     = "my-cluster-id/my-index-name-000001"
        name                   = "my-index-name-000001"
      ~ settings_raw           = jsonencode(
            {
               ... everything is deleted...
            }
        ) -> (known after apply)
        # (7 unchanged attributes hidden)

      - alias {
          - is_hidden      = false -> null
          - is_write_index = true -> null
          - name           = "my-alias" -> null
            # (3 unchanged attributes hidden)
        }
      + alias {
          + is_hidden      = false
          + is_write_index = false
          + name           = "my-alias"
            # (3 unchanged attributes hidden)
        }
    }

[tobio]

@daemitus are you able to provide the output of GET /my-index-name-000001?flat_settings=true and the actual TF definition?

[daemitus]

terraform {
  required_version = "1.8.2"
  required_providers {
    elasticstack = {
      source  = "elastic/elasticstack"
      version = "= 0.11.6"
    }
  }
}

provider "elasticstack" {
  elasticsearch {
    username  = "elastic"
    password  = "password"
    endpoints = ["https://localhost:9200"]
    insecure  = true
  }
}

resource "elasticstack_elasticsearch_index_template" "test" {
  name           = "test"
  index_patterns = ["test*"]
  template {
    settings = jsonencode({
      default_pipeline = ".fleet_final_pipeline-1"
      lifecycle        = { name = ".monitoring-8-ilm-policy" }
    })
  }
}

resource "elasticstack_elasticsearch_index" "test" {
  name                = "test-index-000001"
  deletion_protection = false
  alias {
    name           = "test-alias"
    is_write_index = true
  }
  lifecycle {
    ignore_changes = [mappings]
  }
  depends_on = [elasticstack_elasticsearch_index_template.test]
}

• Apply resources as typical
• Add ~/.terraformrc with

provider_installation {
    dev_overrides {
        "registry.terraform.io/elastic/elasticstack" = "/path/to/terraform-provider-elasticstack"
    }
}

• Build the provider
• git clone https://github.com/elastic/terraform-provider-elasticstack
• git reset --hard 6965f19
• run plan

  # elasticstack_elasticsearch_index.test will be updated in-place
  ~ resource "elasticstack_elasticsearch_index" "test" {
      - default_pipeline       = ".fleet_final_pipeline-1" -> null
        id                     = "nJI3zxCpRJaH7fF1JuQNgw/test-index-000001"
        name                   = "test-index-000001"
      ~ settings_raw           = jsonencode(
            {
              - "index.creation_date"                               = "1726161860563"
              - "index.default_pipeline"                            = ".fleet_final_pipeline-1"
              - "index.lifecycle.name"                              = ".monitoring-8-ilm-policy"
              - "index.number_of_replicas"                          = "1"
              - "index.number_of_shards"                            = "1"
              - "index.priority"                                    = "100"
              - "index.provided_name"                               = "test-index-000001"
              - "index.routing.allocation.include._tier_preference" = "data_content"
              - "index.uuid"                                        = "djLsGFs5R6CfXtymTZ8uig"
              - "index.version.created"                             = "8503000"
            }
        ) -> (known after apply)
        # (7 unchanged attributes hidden)

      - alias {
          - is_hidden      = false -> null
          - is_write_index = true -> null
          - name           = "test-alias" -> null
            # (3 unchanged attributes hidden)
        }
      + alias {
          + is_hidden      = false
          + is_write_index = false
          + name           = "test-alias"
            # (3 unchanged attributes hidden)
        }
    }

Plan: 0 to add, 1 to change, 0 to destroy.```

- `tf state rm elasticstack_elasticsearch_index.test`

Removed elasticstack_elasticsearch_index.test
Successfully removed 1 resource instance(s).

• tf import elasticstack_elasticsearch_index.test nJI3zxCpRJaH7fF1JuQNgw/test-index-000001

elasticstack_elasticsearch_index.test: Importing from ID "nJI3zxCpRJaH7fF1JuQNgw/test-index-000001"...
╷
│ Error: Resource Import Not Implemented
│
│ This resource does not support import. Please contact the provider developer for additional information.
╵

[daemitus]

✗ curl -k -u elastic:password 'https://localhost:9200/test-index-000001?flat_settings=true'
{"test-index-000001":{"aliases":{"test-alias":{"is_write_index":true}},"mappings":{},"settings":{"index.creation_date":"1726161860563","index.default_pipeline":".fleet_final_pipeline-1","index.lifecycle.name":".monitoring-8-ilm-policy","index.number_of_replicas":"1","index.number_of_shards":"1","index.priority":"100","index.provided_name":"test-index-000001","index.routing.allocation.include._tier_preference":"data_content","index.uuid":"djLsGFs5R6CfXtymTZ8uig","index.version.created":"8503000"}}}