Update Filebeat development guide && create _meta/kibana/default fold…

…er (#4787) (#4886)

* create_fileset: Create kibana/default folder

kibana/default folder is created under _meta to be
more consistent with the development guide.

* filebeat: update development guide on dashboards

The way dashboards are exported has changed, so it followed up
in the development guide. It also includes the export of dashboards
before 6.x.

docs/devguide/modules-dev-guide.asciidoc

@@ -52,6 +52,8 @@ module/{module}/{fileset}
 │   └── pipeline.json
 ├── _meta
 │   └── fields.yml
+│   └── kibana
+│       └── default
 └── test
 ----
 
@@ -306,11 +308,24 @@ them, you can build them visually in Kibana and then run the following command:
 
 [source,shell]
 ----
-$ cd filebeat/module/{module}/
-python ../../../dev-tools/export_dashboards.py --regex {module} --dir _meta/kibana
+$ cd dev-tools/cmd/dashboards
+$ make # if export_dashboard is not built
+$ ./export_dashboards -dashboard '{dashboard-id}' -output '../../../filebeat/module/{module}/_meta/kibana/default/dashboard'
+----
+
+New Filebeat modules might not be compatible with Kibana 5.x. To export dashboards that are compatible with 5.x, run the following command inside the developer virtualenv:
+
+[source,shell]
+----
+$ cd filebeat
+$ make python-env
+$ cd module/{module}/
+$ python ../../../dev-tools/export_5x_dashboards.py --regex {module} --dir _meta/kibana/5.x
 ----
 
 Where the `--regex` parameter should match the dashboard you want to export.
 
+Please note that dashboards exported from Kibana 5.x are not compatible with Kibana 6.x.
+
 You can find more details about the process of creating and exporting the Kibana
 dashboards by reading {beatsdevguide}/new-dashboards.html[this guide].

filebeat/scripts/create_fileset.py

@@ -46,13 +46,16 @@ def generate_module(base_path, metricbeat_path, module, fileset):
 
     module_path = base_path + "/module/" + module
     meta_path = module_path + "/_meta"
+    kibana_default_path = meta_path + "/kibana/default"
 
     if os.path.isdir(module_path):
         print("Module already exists. Skipping creating module {}"
               .format(module))
         return
 
-    os.makedirs(meta_path)
+    paths_to_create = [meta_path, kibana_default_path]
+    for path_to_create in paths_to_create:
+        os.makedirs(path_to_create)
 
     templates = metricbeat_path + "/scripts/module/"