When selecting a image for cluster, many invalid images are shown.

If a project has a lot of images, options can be quite long, and
cause wrong selctiong by mistake. So I add a filter after fetching
images, now images that has "os_distro" property and it's value is
one of "fedora-atomic", "coreos" and "ubuntu" are shown

Story: 2003614
Task: 25739
Change-Id: I8db4422f4cf528da0ec592525851cc2c709fff7c

magnum_ui/static/dashboard/container-infra/cluster-templates/cluster-templates.module.js

@@ -33,6 +33,7 @@
       'horizon.dashboard.container-infra.cluster-templates.details'
     ])
     .constant('horizon.dashboard.container-infra.cluster-templates.events', events())
+    .constant('horizon.dashboard.container-infra.cluster-templates.distros', distros())
     .constant(
       'horizon.dashboard.container-infra.cluster-templates.resourceType',
       'OS::Magnum::ClusterTemplate')
@@ -52,6 +53,16 @@
     };
   }
 
+  /**
+   * @ngdoc constant
+   * @name distros
+   * @return [distros] available image distros
+   * @description A list available image distros for magnum
+  */
+  function distros() {
+    return ["fedora-atomic", "coreos", "ubuntu"];
+  }
+
   run.$inject = [
     'horizon.framework.conf.resource-type-registry.service',
     'horizon.dashboard.container-infra.cluster-templates.service',

magnum_ui/static/dashboard/container-infra/cluster-templates/workflow/workflow.service.js

@@ -30,10 +30,20 @@
     'horizon.framework.util.i18n.gettext',
     'horizon.app.core.openstack-service-api.magnum',
     'horizon.app.core.openstack-service-api.nova',
-    'horizon.app.core.openstack-service-api.glance'
+    'horizon.app.core.openstack-service-api.glance',
+    'horizon.dashboard.container-infra.cluster-templates.distros'
   ];
 
-  function ClusterTemplateWorkflow($q, basePath, workflowService, gettext, magnum, nova, glance) {
+  function ClusterTemplateWorkflow(
+    $q,
+    basePath,
+    workflowService,
+    gettext,
+    magnum,
+    nova,
+    glance,
+    distros
+  ) {
     var workflow = {
       init: init,
       update: update
@@ -507,7 +517,10 @@
     function onGetImages(response) {
       images = [{value:"", name: gettext("Choose an Image")}];
       angular.forEach(response.data.items, function(item) {
+        if (!angular.isUndefined(item.properties) &&
+          distros.indexOf(item.properties.os_distro) >= 0) {
           images.push({value: item.name, name: item.name});
+        }
       });
       form[0].tabs[1].items[0].items[0].items[0].titleMap = images;
       var deferred = $q.defer();