FluentdをHTTP経由でコンフィグロードして起動させるワンライナーhack

launch-fluentd-on-httpconf.md

FluentdをHTTP経由でコンフィグロードして起動させるワンライナーhack

fluentd -i "include http://localhost:3000/fluentd.conf" -c /dev/null 

or

curl -s -S http://localhost:3000/fluentd.conf | fluentd -i - -c /dev/null 

前者の方法は-HUP送っても再読み込みしてくれる。 後者の方法だと-HUP送るとcurl経由のconfigが消えるので注意。

fluentd 0.10.42

http://localhost:3000/fluentd.conf の内容

<source>
  type tcp
  port 20000
</source>
<match **>
  type stdout
</match>

起動ログ

 $ curl -s -S http://localhost:3000/fluentd.conf | be fluentd -i - -c /dev/null
2014-04-04 11:47:20 +0900 [info]: starting fluentd-0.10.42
2014-04-04 11:47:20 +0900 [info]: reading config file path="/dev/null"
2014-04-04 11:47:20 +0900 [info]: gem 'fluentd' version '0.10.42'
2014-04-04 11:47:20 +0900 [info]: using configuration file: <ROOT>
  <source>
    type tcp
    port 20000
  </source>
  <match **>
    type stdout
  </match>
</ROOT>
2014-04-04 11:47:20 +0900 [info]: adding source type="tcp"
2014-04-04 11:47:20 +0900 [warn]: 'tcp' input is obsoleted and will be removed soon. Use 'forward' instead.
2014-04-04 11:47:20 +0900 [info]: adding match pattern="**" type="stdout"
2014-04-04 11:47:20 +0900 [info]: listening fluent socket on 0.0.0.0:20000

webサーバが落ちてたらどうなるの?

fluentd -i "include http://localhost:3000/fluentd.conf" -c /dev/null 

で起動させた後、Webサーバを落としてfluentdにHUPを送ってたらfluentdはerror吐いて落ちたので、最悪プロセス監視とかログ監視で気づける。

2014-04-04 14:06:03 +0900 [info]: restarting
2014-04-04 14:06:03 +0900 [info]: shutting down fluentd
2014-04-04 14:06:04 +0900 [info]: process finished code=0
2014-04-04 14:06:04 +0900 [error]: fluentd main process died unexpectedly. restarting.
2014-04-04 14:06:04 +0900 [info]: starting fluentd-0.10.42
2014-04-04 14:06:04 +0900 [info]: reading config file path="/dev/null"
2014-04-04 14:06:04 +0900 [error]: config error file="/dev/null" error="include error at null line 2: Connection refused - connect(2) for \"localhost\" port 3000"
2014-04-04 14:06:04 +0900 [info]: process finished code=256
2014-04-04 14:06:04 +0900 [warn]: process died within 1 second. exit.