LimitNOFILE configurable by es_max_open_files

defaults/main.yml

@@ -17,4 +17,6 @@ es_pid_dir: "/var/run/elasticsearch"
 es_data_dirs: "/var/lib/elasticsearch"
 es_log_dir: "/var/log/elasticsearch"
 es_work_dir: "/tmp/elasticsearch"
-es_plugin_dir: "/usr/share/elasticsearch/plugins"
+es_plugin_dir: "/usr/share/elasticsearch/plugins"
+es_max_open_files: 65535
+

templates/systemd/elasticsearch.j2

@@ -31,7 +31,7 @@ StandardOutput=null
 StandardError=journal
 
 # Specifies the maximum file descriptor number that can be opened by this process
-LimitNOFILE=65535
+LimitNOFILE={{es_max_open_files}}
 
 # Specifies the maximum number of bytes of memory that may be locked into RAM
 # Set to "infinity" if you use the 'bootstrap.mlockall: true' option
@@ -53,4 +53,4 @@ SendSIGKILL=no
 SuccessExitStatus=143
 
 [Install]
-WantedBy=multi-user.target
+WantedBy=multi-user.target