Query server time info (#15)

* add query server time info

* add query server time info

* add query server time info

* add query server time info

* add query server time info

.graphqlconfig

+{
+  "name": "Skywalking GraphQL Schema",
+  "schemaPath": "schema.graphql",
+  "extensions": {
+    "endpoints": {
+      "Dev GraphQL Endpoint": {
+        "url": "http://localhost:12800/graphql",
+        "headers": {
+          "user-agent": "JS GraphQL"
+        },
+        "introspect": false
+      }
+    }
+  }
+}
\ No newline at end of file

metadata.graphqls

@@ -58,6 +58,13 @@ type Database {
     type: String!
 }
 
+type TimeInfo {
+  # server current timezone
+  timezone: String
+  # server current timestamp
+  currentTimestamp: Long
+}
+
 extend type Query {
     getGlobalBrief(duration: Duration!): ClusterBrief
 
@@ -77,4 +84,5 @@ extend type Query {
 
     # Database related meta info.
     getAllDatabases(duration: Duration!): [Database!]!
+    getTimeInfo: TimeInfo
 }