ES: return .raw fields in field lookups, closes #8975

public/app/plugins/datasource/elasticsearch/datasource.js

@@ -272,10 +272,17 @@ function (angular, _, moment, kbn, ElasticQueryBuilder, IndexPattern, ElasticRes
             var subObj = obj[key];
 
             // Check mapping field for nested fields
-            if (subObj.hasOwnProperty('properties')) {
+            if (_.isObject(subObj.properties)) {
               fieldNameParts.push(key);
               getFieldsRecursively(subObj.properties);
-            } else {
+            }
+
+            if (_.isObject(subObj.fields)) {
+              fieldNameParts.push(key);
+              getFieldsRecursively(subObj.fields);
+            }
+
+            if (_.isString(subObj.type)) {
               var fieldName = fieldNameParts.concat(key).join('.');
 
               // Hide meta-fields and check field type

public/app/plugins/datasource/elasticsearch/specs/datasource_specs.ts

@@ -129,7 +129,10 @@ describe('ElasticDatasource', function() {
                   '@timestamp': {type: 'date'},
                   beat: {
                     properties: {
-                      name: {type: 'string'},
+                      name: {
+                        fields: {raw: {type: 'keyword'}},
+                        type: 'string'
+                      },
                       hostname: {type: 'string'},
                     }
                   },
@@ -169,6 +172,7 @@ describe('ElasticDatasource', function() {
         var fields = _.map(fieldObjects, 'text');
         expect(fields).to.eql([
           '@timestamp',
+          'beat.name.raw',
           'beat.name',
           'beat.hostname',
           'system.cpu.system',