Make headers required for telemetry drains and add space-scoped drain test

- API testing revealed headers are required for all telemetry drains
- Updated schema to make headers required instead of optional
- Added space-scoped telemetry drain back to acceptance test with headers
- Updated documentation to reflect headers requirement
- Both app-scoped and space-scoped drains now work correctly

Author: heroku-johnny

docs/resources/telemetry_drain.md

@@ -100,7 +100,7 @@ The following arguments are supported:
   * `"traces"` - Distributed tracing data
   * `"metrics"` - Application and system metrics
   * `"logs"` - Application and system logs
-* `headers` - (Optional) A map of headers to send to your OpenTelemetry consumer for authentication or configuration.
+* `headers` - (Required) A map of headers to send to your OpenTelemetry consumer for authentication or configuration. At least one header must be specified.
 
 ## Attributes Reference
 

heroku/resource_heroku_telemetry_drain.go

@@ -60,7 +60,7 @@ func resourceHerokuTelemetryDrain() *schema.Resource {
 
 			"headers": {
 				Type:        schema.TypeMap,
-				Optional:    true,
+				Required:    true,
 				Description: "Headers to send to your OpenTelemetry consumer",
 				Elem: &schema.Schema{
 					Type: schema.TypeString,

heroku/resource_heroku_telemetry_drain_test.go

@@ -104,6 +104,18 @@ resource "heroku_telemetry_drain" "app_test" {
   headers = {
     "x-honeycomb-team" = "test-key"
   }
+}
+
+resource "heroku_telemetry_drain" "space_test" {
+  owner_id      = heroku_space.foobar.id
+  owner_type    = "space"
+  endpoint      = "https://logs.datadog.com/api/v2/logs"
+  exporter_type = "otlphttp"
+  signals       = ["logs"]
+  
+  headers = {
+    "DD-API-KEY" = "test-space-key"
+  }
 }`,
 		spaceConfig, appName, testAccConfig.GetOrganizationOrSkip(t))
 
@@ -119,6 +131,16 @@ resource "heroku_telemetry_drain" "app_test" {
 			resource.TestCheckResourceAttrSet("heroku_telemetry_drain.app_test", "id"),
 			resource.TestCheckResourceAttrSet("heroku_telemetry_drain.app_test", "created_at"),
 			resource.TestCheckResourceAttrSet("heroku_telemetry_drain.app_test", "updated_at"),
+
+			// Check space-scoped telemetry drain
+			resource.TestCheckResourceAttr("heroku_telemetry_drain.space_test", "owner_type", "space"),
+			resource.TestCheckResourceAttr("heroku_telemetry_drain.space_test", "endpoint", "https://logs.datadog.com/api/v2/logs"),
+			resource.TestCheckResourceAttr("heroku_telemetry_drain.space_test", "exporter_type", "otlphttp"),
+			resource.TestCheckResourceAttr("heroku_telemetry_drain.space_test", "signals.#", "1"),
+			resource.TestCheckResourceAttr("heroku_telemetry_drain.space_test", "headers.DD-API-KEY", "test-space-key"),
+			resource.TestCheckResourceAttrSet("heroku_telemetry_drain.space_test", "id"),
+			resource.TestCheckResourceAttrSet("heroku_telemetry_drain.space_test", "created_at"),
+			resource.TestCheckResourceAttrSet("heroku_telemetry_drain.app_test", "updated_at"),
 		),
 	}
 }