Add namespcace ID attribute (#14483)

* Add namespcace ID attribute

This commit also introduce `id` comouted value which is numeric value
used by GitLab to iteract with repository. This should simplify use of
`gitlab_project_hook` usage and would allow to introduce other resources
as described in #14471

* Fixes requested by @richardc

* Handle optional `namespace_id`

builtin/providers/gitlab/resource_gitlab_project.go

@@ -21,6 +21,10 @@ func resourceGitlabProject() *schema.Resource {
 				Type:     schema.TypeString,
 				Required: true,
 			},
+			"namespace_id": {
+				Type:     schema.TypeInt,
+				Optional: true,
+			},
 			"description": {
 				Type:     schema.TypeString,
 				Optional: true,
@@ -97,6 +101,10 @@ func resourceGitlabProjectCreate(d *schema.ResourceData, meta interface{}) error
 		SnippetsEnabled:      gitlab.Bool(d.Get("snippets_enabled").(bool)),
 	}
 
+	if v, ok := d.GetOk("namespace_id"); ok {
+		options.NamespaceID = gitlab.Int(v.(int))
+	}
+
 	if v, ok := d.GetOk("description"); ok {
 		options.Description = gitlab.String(v.(string))
 	}

builtin/providers/gitlab/resource_gitlab_project_hook_test.go

@@ -186,8 +186,8 @@ resource "gitlab_project" "foo" {
 }
 
 resource "gitlab_project_hook" "foo" {
-	project = "${gitlab_project.foo.id}"
-	url = "https://example.com/hook-%d"
+  project = "${gitlab_project.foo.id}"
+  url = "https://example.com/hook-%d"
 }
 	`, rInt, rInt)
 }
@@ -204,17 +204,17 @@ resource "gitlab_project" "foo" {
 }
 
 resource "gitlab_project_hook" "foo" {
-	project = "${gitlab_project.foo.id}"
-	url = "https://example.com/hook-%d"
-	enable_ssl_verification = false
-	push_events = false
-	issues_events = true
-	merge_requests_events = true
-	tag_push_events = true
-	note_events = true
-	build_events = true
-	pipeline_events = true
-	wiki_page_events = true
+  project = "${gitlab_project.foo.id}"
+  url = "https://example.com/hook-%d"
+  enable_ssl_verification = false
+  push_events = false
+  issues_events = true
+  merge_requests_events = true
+  tag_push_events = true
+  note_events = true
+  build_events = true
+  pipeline_events = true
+  wiki_page_events = true
 }
 	`, rInt, rInt)
 }

builtin/providers/gitlab/resource_gitlab_project_test.go

@@ -182,10 +182,10 @@ resource "gitlab_project" "foo" {
   # with no billing
   visibility_level = "public"
 
-	issues_enabled = false
-	merge_requests_enabled = false
-	wiki_enabled = false
-	snippets_enabled = false
+  issues_enabled = false
+  merge_requests_enabled = false
+  wiki_enabled = false
+  snippets_enabled = false
 }
 	`, rInt)
 }