Add export of node group templates

Partially-Implements: bp portable-node-group-and-cluster-templates

Depends-On: I33c3b6daa5b9e2be218a84efdb6113a4ce9a86df

This change adds functions to saharaclient to enable export of ngt
to JSON.

Change-Id: Ic5d9dffd0a3ae21a28ecbcfdd88f5cd1194551bb

requirements.txt

@@ -8,6 +8,7 @@ Django<2.0,>=1.8 # BSD
 django-compressor>=2.0 # MIT
 django-openstack-auth>=3.5.0 # Apache-2.0
 oslo.log>=3.30.0 # Apache-2.0
+oslo.serialization!=2.19.1,>=1.10.0 # Apache-2.0
 python-designateclient>=1.5.0 # Apache-2.0
 python-keystoneclient>=3.8.0 # Apache-2.0
 python-manilaclient>=1.12.0 # Apache-2.0

sahara_dashboard/api/sahara.py

@@ -259,6 +259,10 @@ def nodegroup_update_acl_rules(request, nid,
         nid, **prepare_acl_update_dict(is_public, is_protected))
 
 
+def nodegroup_template_export(request, object_id):
+    return client(request).node_group_templates.export(object_id)
+
+
 def cluster_template_create(request, name, plugin_name, hadoop_version,
                             description=None, cluster_configs=None,
                             node_groups=None, anti_affinity=None,

sahara_dashboard/content/data_processing/clusters/nodegroup_templates/tables.py

@@ -11,12 +11,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from django import http
 from django.template import defaultfilters as filters
 from django.utils.translation import ugettext_lazy as _
 from django.utils.translation import ungettext_lazy
 
 from horizon import tables
 from horizon.tabs import base as tabs_base
+from oslo_serialization import jsonutils as json
 
 from sahara_dashboard.api import sahara as saharaclient
 from sahara_dashboard.content.data_processing \
@@ -65,6 +67,22 @@ class EditTemplate(tables.LinkAction):
     classes = ("ajax-modal", )
 
 
+class ExportTemplate(tables.Action):
+    name = "export"
+    verbose_name = _("Export Template")
+    classes = ("ajax-modal", )
+
+    def single(self, data_table, request, object_id):
+        content = json.dumps(saharaclient.nodegroup_template_export(
+            request, object_id)._info)
+        response = http.HttpResponse(content, content_type="application/json")
+        filename = '%s-node-group-template.json' % object_id
+        disposition = 'attachment; filename="%s"' % filename
+        response['Content-Disposition'] = disposition.encode('utf-8')
+        response['Content-Length'] = str(len(response.content))
+        return response
+
+
 class DeleteTemplate(tables.DeleteAction):
     @staticmethod
     def action_present(count):
@@ -138,5 +156,6 @@ class NodegroupTemplatesTable(sahara_table.SaharaPaginateTabbedTable):
                               MakeUnProtected)
         row_actions = (EditTemplate,
                        CopyTemplate,
+                       ExportTemplate,
                        DeleteTemplate, MakePublic, MakePrivate, MakeProtected,
                        MakeUnProtected)