Make allocation pages extend the job breadcrumb trail

ui/app/controllers/allocations/allocation.js

 import Controller from '@ember/controller';
+import { computed } from '@ember/object';
+import { qpBuilder } from 'nomad-ui/utils/classes/query-params';
 
-export default Controller.extend({});
+export default Controller.extend({
+  breadcrumbs: computed('model.job', function() {
+    return [
+      { label: 'Jobs', args: ['jobs'] },
+      {
+        label: this.get('model.job.name'),
+        args: [
+          'jobs.job',
+          this.get('model.job'),
+          qpBuilder({
+            jobNamespace: this.get('model.namespace.name') || 'default',
+          }),
+        ],
+      },
+      {
+        label: this.get('model.taskGroupName'),
+        args: [
+          'jobs.job.task-group',
+          this.get('model.job'),
+          this.get('model.taskGroupName'),
+          qpBuilder({
+            jobNamespace: this.get('model.namespace.name') || 'default',
+          }),
+        ],
+      },
+      {
+        label: this.get('model.shortId'),
+        args: ['allocations.allocation', this.get('model')],
+      },
+    ];
+  }),
+});

ui/app/controllers/allocations/allocation/index.js

 import { alias } from '@ember/object/computed';
-import Controller from '@ember/controller';
+import Controller, { inject as controller } from '@ember/controller';
 import Sortable from 'nomad-ui/mixins/sortable';
 
 export default Controller.extend(Sortable, {
+  allocationController: controller('allocations.allocation'),
+
   queryParams: {
     sortProperty: 'sort',
     sortDescending: 'desc',
@@ -11,6 +13,8 @@ export default Controller.extend(Sortable, {
   sortProperty: 'name',
   sortDescending: false,
 
+  breadcrumbs: alias('allocationController.breadcrumbs'),
+
   listToSort: alias('model.states'),
   sortedStates: alias('listSorted'),
 });

ui/app/routes/allocations/allocation.js

 import Route from '@ember/routing/route';
-import WithModelErrorHandling from 'nomad-ui/mixins/with-model-error-handling';
 import { collect } from '@ember/object/computed';
 import { watchRecord } from 'nomad-ui/utils/properties/watch';
 import WithWatchers from 'nomad-ui/mixins/with-watchers';
+import notifyError from 'nomad-ui/utils/notify-error';
 
-export default Route.extend(WithModelErrorHandling, WithWatchers, {
+export default Route.extend(WithWatchers, {
   startWatchers(controller, model) {
     controller.set('watcher', this.get('watch').perform(model));
   },
 
+  model() {
+    // Preload the job for the allocation since it's required for the breadcrumb trail
+    return this._super(...arguments)
+      .then(allocation => allocation.get('job').then(() => allocation))
+      .catch(notifyError(this));
+  },
+
   watch: watchRecord('allocation'),
 
   watchers: collect('watch'),

ui/app/templates/allocations/allocation/index.hbs

 {{#global-header class="page-header"}}
-  <li><a href="#">Allocations</a></li>
-  <li class="is-active">
-    {{#link-to "allocations.allocation" model}}{{model.shortId}}{{/link-to}}
-  </li>
+  {{#each breadcrumbs as |breadcrumb index|}}
+    <li class="{{if (eq (inc index) breadcrumbs.length) "is-active"}}">
+      {{#link-to
+        data-test-breadcrumb=breadcrumb.label
+        params=breadcrumb.args}}
+        {{breadcrumb.label}}
+      {{/link-to}}
+    </li>
+  {{/each}}
 {{/global-header}}
 {{#gutter-menu class="page-body"}}
   <section class="section">