YUKI Hiroshi
null+****@clear*****
Mon Feb 3 13:04:32 JST 2014
YUKI Hiroshi 2014-02-03 13:04:32 +0900 (Mon, 03 Feb 2014) New Revision: 40d3ce986ec29d3e22a58efad1b45ae54f17030c https://github.com/droonga/droonga.org/commit/40d3ce986ec29d3e22a58efad1b45ae54f17030c Message: Copy the tutorial of plugin development for input/output adapter Added files: tutorial/plugin-development/input-output/index.md Added: tutorial/plugin-development/input-output/index.md (+117 -0) 100644 =================================================================== --- /dev/null +++ tutorial/plugin-development/input-output/index.md 2014-02-03 13:04:32 +0900 (25ea277) @@ -0,0 +1,117 @@ +--- +title: Droonga plugin development tutorial +layout: en +--- + +!!WORK IN PROGRESS!! + +* TOC +{:toc} + +## The goal of this tutorial + +Learning steps to develop a Droonga plugin by yourself. + +## Precondition + +* You must complete [tutorial][]. + +## Plugin + +Plugin is one of the most important concept of Droonga. +This makes droonga flexible. + +Generally, data processing tasks in real word need custom treatments of the data, in various stages of the data stream. This is not easy to done in one-size-fits-all approach. + +One may want to modify input queries to work well with other systems, one may want to modify output to help other systems understand the result. One may want to do more complex data processing than that provided by Droonga as built-in, to have direct storage access for efficiency. One may need to control data distribution logic and collection logic of Droonga to profit from distributed nature of Droonga. + +You can use plugins in those situations. + +## Types of plugins + +Droonga has 5 types of plugins corresponding to the purpose of plugin. +In other words, from the point of view of Droonga internal, the type of a plugin is distinguished by the component which the plugin is plugged in. See [overview][] to grasp the big picture. + +InputAdapterPlugin +: used to modify requests. + +OutputAdapterPlugin +: used to modify responses. + +HandlerPlugin +: used for low-level data handling. + +DistributorPlugin +: used to control internal message distribution. + +CollectorPlugin +: used to control internal message collection. + +In this tutorial, we focus on InputAdapterPlugin. This is the most "basic" plugin, so it will help you to understand the overview of Droonga plugin development. + + +## Directory Structure + +Assume that we are going to add `InputAdapterPlugin` to the system built in [tutorial][]. In that tutorial, Groonga engine was placed under `engine` directory. + +Plugins need to be placed in an appropriate directory. For example, `InputAdapterPlugin` should be placed under `lib/droonga/plugin/input_adapter/` directory. Let's create the directory: + + # cd engine + # mkdir -p lib/droonga/plugin/input_adapter + +After creating the directory, the directory structure should be like this: + +``` +engine +├── catalog.json +├── fluentd.conf +└── lib + └── droonga + └── plugin + └── input_adapter +``` + + +## Create a plugin + +Put a plugin code into `input_adapter` directory. + +lib/droonga/plugin/input_adapter/example.rb: + +```ruby +module Droonga + class ExampleInputAdapterPlugin < Droonga::InputAdapterPlugin + repository.register("example", self) + end +end +``` + +This plugin does nothing except registering itself to Droonga. + +## Activate plugin with `catalog.json` + +You need to update `catalog.json` to activate your plugin. +Insert following at the last part of `catalog.json` in order to make `"input_adapter"` become a key of the top level hash: + +catalog.json: +``` +(snip) + }, + "input_adapter": { + "plugins": ["example"] + } +} +``` + +## Run + +Let's Droonga get started. Note that you need to specify `./lib` directory in `RUBYLIB` environment variable in order to make ruby possible to find your plugin. + +``` +RUBYLIB=./lib fluentd --config fluentd.conf +``` + + + + [tutorial]: ../ + [overview]: ../../overview/ -------------- next part -------------- HTML����������������������������...Download