[Feature] Introduce elasticsearch alias resource with atomic write index management and nested attributes

docs/resources/elasticsearch_index.md

@@ -20,16 +20,14 @@ provider "elasticstack" {
 resource "elasticstack_elasticsearch_index" "my_index" {
   name = "my-index"
 
-  alias {
+  alias = [{
     name = "my_alias_1"
-  }
-
-  alias {
+    }, {
     name = "my_alias_2"
     filter = jsonencode({
       term = { "user.id" = "developer" }
     })
-  }
+  }]
 
   mappings = jsonencode({
     properties = {
@@ -59,7 +57,7 @@ resource "elasticstack_elasticsearch_index" "my_index" {
 
 ### Optional
 
-- `alias` (Block Set) Aliases for the index. (see [below for nested schema](#nestedblock--alias))
+- `alias` (Attributes Set) Aliases for the index. (see [below for nested schema](#nestedatt--alias))
 - `analysis_analyzer` (String) A JSON string describing the analyzers applied to the index.
 - `analysis_char_filter` (String) A JSON string describing the char_filters applied to the index.
 - `analysis_filter` (String) A JSON string describing the filters applied to the index.
@@ -135,7 +133,7 @@ resource "elasticstack_elasticsearch_index" "my_index" {
 - `id` (String) Internal identifier of the resource
 - `settings_raw` (String) All raw settings fetched from the cluster.
 
-<a id="nestedblock--alias"></a>
+<a id="nestedatt--alias"></a>
 ### Nested Schema for `alias`
 
 Required:

docs/resources/elasticsearch_index_alias.md

@@ -0,0 +1,60 @@
+---
+# generated by https://github.com/hashicorp/terraform-plugin-docs
+page_title: "elasticstack_elasticsearch_index_alias Resource - terraform-provider-elasticstack"
+subcategory: "Index"
+description: |-
+  Manages an Elasticsearch alias. See the alias documentation https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-aliases.html for more details.
+---
+
+# elasticstack_elasticsearch_index_alias (Resource)
+
+Manages an Elasticsearch alias. See the [alias documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-aliases.html) for more details.
+
+
+
+<!-- schema generated by tfplugindocs -->
+## Schema
+
+### Required
+
+- `name` (String) The alias name.
+
+### Optional
+
+- `read_indices` (Attributes Set) Set of read indices for the alias. (see [below for nested schema](#nestedatt--read_indices))
+- `write_index` (Attributes) The write index for the alias. Only one write index is allowed per alias. (see [below for nested schema](#nestedatt--write_index))
+
+### Read-Only
+
+- `id` (String) Generated ID of the alias resource.
+
+<a id="nestedatt--read_indices"></a>
+### Nested Schema for `read_indices`
+
+Required:
+
+- `name` (String) Name of the read index.
+
+Optional:
+
+- `filter` (String) Query used to limit documents the alias can access.
+- `index_routing` (String) Value used to route indexing operations to a specific shard.
+- `is_hidden` (Boolean) If true, the alias is hidden.
+- `routing` (String) Value used to route indexing and search operations to a specific shard.
+- `search_routing` (String) Value used to route search operations to a specific shard.
+
+
+<a id="nestedatt--write_index"></a>
+### Nested Schema for `write_index`
+
+Required:
+
+- `name` (String) Name of the write index.
+
+Optional:
+
+- `filter` (String) Query used to limit documents the alias can access.
+- `index_routing` (String) Value used to route indexing operations to a specific shard.
+- `is_hidden` (Boolean) If true, the alias is hidden.
+- `routing` (String) Value used to route indexing and search operations to a specific shard.
+- `search_routing` (String) Value used to route search operations to a specific shard.

examples/resources/elasticstack_elasticsearch_index/resource.tf

@@ -5,16 +5,14 @@ provider "elasticstack" {
 resource "elasticstack_elasticsearch_index" "my_index" {
   name = "my-index"
 
-  alias {
+  alias = [{
     name = "my_alias_1"
-  }
-
-  alias {
+    }, {
     name = "my_alias_2"
     filter = jsonencode({
       term = { "user.id" = "developer" }
     })
-  }
+  }]
 
   mappings = jsonencode({
     properties = {

internal/clients/elasticsearch/index.go

@@ -581,6 +581,133 @@ func DeleteDataStreamLifecycle(ctx context.Context, apiClient *clients.ApiClient
 	return nil
 }
 
+func GetAlias(ctx context.Context, apiClient *clients.ApiClient, aliasName string) (map[string]models.Index, fwdiags.Diagnostics) {
+	esClient, err := apiClient.GetESClient()
+	if err != nil {
+		return nil, fwdiags.Diagnostics{
+			fwdiags.NewErrorDiagnostic(err.Error(), err.Error()),
+		}
+	}
+
+	res, err := esClient.Indices.GetAlias(
+		esClient.Indices.GetAlias.WithName(aliasName),
+		esClient.Indices.GetAlias.WithContext(ctx),
+	)
+	if err != nil {
+		return nil, fwdiags.Diagnostics{
+			fwdiags.NewErrorDiagnostic(err.Error(), err.Error()),
+		}
+	}
+	defer res.Body.Close()
+
+	if res.StatusCode == http.StatusNotFound {
+		return nil, nil
+	}
+
+	diags := diagutil.CheckErrorFromFW(res, fmt.Sprintf("Unable to get alias '%s'", aliasName))
+	if diags.HasError() {
+		return nil, diags
+	}
+
+	indices := make(map[string]models.Index)
+	if err := json.NewDecoder(res.Body).Decode(&indices); err != nil {
+		return nil, fwdiags.Diagnostics{
+			fwdiags.NewErrorDiagnostic(err.Error(), err.Error()),
+		}
+	}
+
+	return indices, nil
+}
+
+// AliasAction represents a single action in an atomic alias update operation
+type AliasAction struct {
+	Type          string // "add" or "remove"
+	Index         string
+	Alias         string
+	IsWriteIndex  bool
+	Filter        map[string]interface{}
+	IndexRouting  string
+	IsHidden      bool
+	Routing       string
+	SearchRouting string
+}
+
+// UpdateAliasesAtomic performs atomic alias updates using multiple actions
+func UpdateAliasesAtomic(ctx context.Context, apiClient *clients.ApiClient, actions []AliasAction) fwdiags.Diagnostics {
+	esClient, err := apiClient.GetESClient()
+	if err != nil {
+		return fwdiags.Diagnostics{
+			fwdiags.NewErrorDiagnostic(err.Error(), err.Error()),
+		}
+	}
+
+	var aliasActions []map[string]interface{}
+
+	for _, action := range actions {
+		switch action.Type {
+		case "remove":
+			aliasActions = append(aliasActions, map[string]interface{}{
+				"remove": map[string]interface{}{
+					"index": action.Index,
+					"alias": action.Alias,
+				},
+			})
+		case "add":
+			addDetails := map[string]interface{}{
+				"index": action.Index,
+				"alias": action.Alias,
+			}
+
+			if action.IsWriteIndex {
+				addDetails["is_write_index"] = true
+			}
+			if action.Filter != nil {
+				addDetails["filter"] = action.Filter
+			}
+			if action.IndexRouting != "" {
+				addDetails["index_routing"] = action.IndexRouting
+			}
+			if action.SearchRouting != "" {
+				addDetails["search_routing"] = action.SearchRouting
+			}
+			if action.Routing != "" {
+				addDetails["routing"] = action.Routing
+			}
+			if action.IsHidden {
+				addDetails["is_hidden"] = action.IsHidden
+			}
+
+			aliasActions = append(aliasActions, map[string]interface{}{
+				"add": addDetails,
+			})
+		}
+	}
+
+	requestBody := map[string]interface{}{
+		"actions": aliasActions,
+	}
+
+	aliasBytes, err := json.Marshal(requestBody)
+	if err != nil {
+		return fwdiags.Diagnostics{
+			fwdiags.NewErrorDiagnostic(err.Error(), err.Error()),
+		}
+	}
+
+	res, err := esClient.Indices.UpdateAliases(
+		bytes.NewReader(aliasBytes),
+		esClient.Indices.UpdateAliases.WithContext(ctx),
+	)
+	if err != nil {
+		return fwdiags.Diagnostics{
+			fwdiags.NewErrorDiagnostic(err.Error(), err.Error()),
+		}
+	}
+	defer res.Body.Close()
+
+	return diagutil.CheckErrorFromFW(res, "Unable to update aliases atomically")
+}
+
 func PutIngestPipeline(ctx context.Context, apiClient *clients.ApiClient, pipeline *models.IngestPipeline) diag.Diagnostics {
 	var diags diag.Diagnostics
 	pipelineBytes, err := json.Marshal(pipeline)