Add service.name and event.dataset to spec (#32)

Author: felixbarny

spec/spec.json

@@ -50,6 +50,32 @@
             "required": false,
             "url": "https://www.elastic.co/guide/en/ecs/current/ecs-tracing.html",
             "comment": "When APM agents add this field to the context, ecs loggers should pick it up and add it to the log event."
+        },
+        "service.name": {
+            "type": "string",
+            "required": false,
+            "url": "https://www.elastic.co/guide/en/ecs/current/ecs-service.html",
+            "comment": [
+                "Configurable by users.",
+                "When an APM agent is active, they should auto-configure it if not already set."
+            ]
+        },
+        "event.dataset": {
+            "type": "string",
+            "required": false,
+            "url": "https://www.elastic.co/guide/en/ecs/current/ecs-event.html",
+            "default": "${service.name}.log OR ${service.name}.${appender.name}",
+            "comment": [
+                "Configurable by users.",
+                "If the user manually configures the service name,",
+                "the logging library should set `event.dataset=${service.name}.log` if not explicitly configured otherwise.",
+                "",
+                "When agents auto-configure the app to use an ECS logger,",
+                "they should set `event.dataset=${service.name}.${appender.name}` if the appender name is available in the logging library.",
+                "Otherwise, agents should also set `event.dataset=${service.name}.log`",
+                "",
+                "The field helps to filter for different log streams from the same pod, for example and is required for log anomaly detection."
+            ]
         }
     }
 }