devenv: proper fluentd conf for grafana and loki

devenv/docker/ha_test/fluentd/fluentd.conf

@@ -4,13 +4,37 @@
   bind 0.0.0.0
 </source>
 
+<filter grafana>
+  @type parser
+  <parse>
+    @type json
+    json_parser json
+  </parse>
+  replace_invalid_sequence true
+  emit_invalid_record_to_error false
+  key_name log
+  reserve_data true
+  remove_key_name_field true
+</filter>
+
+<filter grafana>
+  @type record_transformer
+  remove_keys "source,t"
+</filter>
+
 <match grafana>
-  @type loki
-  url "http://loki:3100"
-  extra_labels {"app":"grafana"}
-  label_keys "container_name,container_id"
-  line_format "json"
-  flush_interval 10s
-  flush_at_shutdown true
-  buffer_chunk_limit 1m
+  @type copy
+  <store>
+    @type stdout
+    output_type json
+  </store>
+  <store>
+    @type loki
+    url "http://loki:3100"
+    extra_labels {"app":"grafana"}
+    label_keys "container_name,container_id,logger"
+    flush_interval 10s
+    flush_at_shutdown true
+    buffer_chunk_limit 1m
+  </store>
 </match>