From 13a4d23c457deeeb3e7000734f29762f984f28d3 Mon Sep 17 00:00:00 2001
From: Jaime Soriano Pastor <jaime.soriano@elastic.co>
Date: Thu, 8 Sep 2022 16:19:14 +0200
Subject: [PATCH] Allow to override ECS fields type from keyword to
 constant_keyword

---
 internal/fields/dependency_manager.go      |  7 +++++-
 internal/fields/dependency_manager_test.go | 26 ++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/internal/fields/dependency_manager.go b/internal/fields/dependency_manager.go
index 16a945200e..10a199fea1 100644
--- a/internal/fields/dependency_manager.go
+++ b/internal/fields/dependency_manager.go
@@ -160,9 +160,14 @@ func (dm *DependencyManager) injectFieldsWithRoot(root string, defs []common.Map
 
 			// Allow overrides of everything, except the imported type, for consistency.
 			transformed.DeepUpdate(def)
-			transformed["type"] = imported.Type
 			transformed.Delete("external")
 
+			// Allow to override the type only from keyword to constant_keyword,
+			// to support the case of setting the value already in the mappings.
+			if ttype, _ := transformed["type"].(string); ttype != "constant_keyword" || imported.Type != "keyword" {
+				transformed["type"] = imported.Type
+			}
+
 			def = transformed
 			changed = true
 		} else {
diff --git a/internal/fields/dependency_manager_test.go b/internal/fields/dependency_manager_test.go
index 80cf913924..5b6755a336 100644
--- a/internal/fields/dependency_manager_test.go
+++ b/internal/fields/dependency_manager_test.go
@@ -57,6 +57,27 @@ func TestDependencyManagerInjectExternalFields(t *testing.T) {
 			changed: true,
 			valid:   true,
 		},
+		{
+			title: "keyword to constant_keyword override",
+			defs: []common.MapStr{
+				{
+					"name":     "event.dataset",
+					"type":     "constant_keyword",
+					"external": "test",
+					"value":    "nginx.access",
+				},
+			},
+			result: []common.MapStr{
+				{
+					"name":        "event.dataset",
+					"type":        "constant_keyword",
+					"description": "Dataset that collected this event",
+					"value":       "nginx.access",
+				},
+			},
+			changed: true,
+			valid:   true,
+		},
 		{
 			title: "external dimension",
 			defs: []common.MapStr{
@@ -362,6 +383,11 @@ func TestDependencyManagerInjectExternalFields(t *testing.T) {
 			Description: "Data stream dataset.",
 			Type:        "constant_keyword",
 		},
+		{
+			Name:        "event.dataset",
+			Description: "Dataset that collected this event",
+			Type:        "keyword",
+		},
 		{
 			Name:        "process.command_line",
 			Description: "Full command line that started the process.",