Add Logstash config to filter example Nginx logs

Signed-off-by: Jing Li <thyrlian@gmail.com>

elasticsearch-logstash-kibana/logstash/pipeline/logstash-nginx.config

@@ -0,0 +1,30 @@
+input {
+  file {
+    path => "/home/nginx.log"
+    start_position => "beginning"
+    sincedb_path => "/dev/null"
+  }
+}
+
+filter {
+  json {
+    source => "message"
+  }
+  geoip {
+    source => "remote_ip"
+  }
+  useragent {
+    source => "agent"
+    target => "useragent"
+  }
+}
+
+output {
+  elasticsearch {
+    hosts => ["http://es:9200"]
+    index => "nginx"
+  }
+  stdout {
+    codec => rubydebug
+  }
+}