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diff --git a/collectors/node.d.plugin/README.md b/collectors/node.d.plugin/README.md deleted file mode 100644 index 4c5f278b..00000000 --- a/collectors/node.d.plugin/README.md +++ /dev/null @@ -1,236 +0,0 @@ -<!-- -title: "node.d.plugin" -custom_edit_url: https://github.com/netdata/netdata/edit/master/collectors/node.d.plugin/README.md ---> - -# node.d.plugin - -`node.d.plugin` is a Netdata external plugin. It is an **orchestrator** for data collection modules written in `node.js`. - -1. It runs as an independent process `ps fax` shows it -2. It is started and stopped automatically by Netdata -3. It communicates with Netdata via a unidirectional pipe (sending data to the `netdata` daemon) -4. Supports any number of data collection **modules** -5. Allows each **module** to have one or more data collection **jobs** -6. Each **job** is collecting one or more metrics from a single data source - -## Pull Request Checklist for Node.js Plugins - -This is a generic checklist for submitting a new Node.js plugin for Netdata. It is by no means comprehensive. - -At minimum, to be buildable and testable, the PR needs to include: - -- The module itself, following proper naming conventions: `node.d/<module_dir>/<module_name>.node.js` -- A README.md file for the plugin. -- The configuration file for the module -- A basic configuration for the plugin in the appropriate global config file: `conf.d/node.d.conf`, which is also in JSON format. If the module should be enabled by default, add a section for it in the `modules` dictionary. -- A line for the plugin in the appropriate `Makefile.am` file: `node.d/Makefile.am` under `dist_node_DATA`. -- A line for the plugin configuration file in `conf.d/Makefile.am`: under `dist_nodeconfig_DATA` -- Optionally, chart information in `web/dashboard_info.js`. This generally involves specifying a name and icon for the section, and may include descriptions for the section or individual charts. - -## Motivation - -Node.js is perfect for asynchronous operations. It is very fast and quite common (actually the whole web is based on it). -Since data collection is not a CPU intensive task, node.js is an ideal solution for it. - -`node.d.plugin` is a Netdata plugin that provides an abstraction layer to allow easy and quick development of data -collectors in node.js. It also manages all its data collectors (placed in `/usr/libexec/netdata/node.d`) using a single -instance of node, thus lowering the memory footprint of data collection. - -Of course, there can be independent plugins written in node.js (placed in `/usr/libexec/netdata/plugins`). -These will have to be developed using the guidelines of **[External Plugins](/collectors/plugins.d/README.md)**. - -To run `node.js` plugins you need to have `node` installed in your system. - -In some older systems, the package named `node` is not node.js. It is a terminal emulation program called `ax25-node`. -In this case the node.js package may be referred as `nodejs`. Once you install `nodejs`, we suggest to link -`/usr/bin/nodejs` to `/usr/bin/node`, so that typing `node` in your terminal, opens node.js. - -## configuring `node.d.plugin` - -`node.d.plugin` can work even without any configuration. Its default configuration file is -`node.d.conf`. To edit it on your system, run `/etc/netdata/edit-config node.d.conf`. - -## configuring `node.d.plugin` modules - -`node.d.plugin` modules accept configuration in `JSON` format. - -Unfortunately, `JSON` files do not accept comments. So, the best way to describe them is to have markdown text files -with instructions. - -`JSON` has a very strict formatting. If you get errors from Netdata at `/var/log/netdata/error.log` that a certain -configuration file cannot be loaded, we suggest to verify it at <http://jsonlint.com/>. - -The files in this directory, provide usable examples for configuring each `node.d.plugin` module. - -## debugging modules written for node.d.plugin - -To test `node.d.plugin` modules, which are placed in `/usr/libexec/netdata/node.d`, you can run `node.d.plugin` by hand, -like this: - -```sh -# become user netdata -sudo su -s /bin/sh netdata - -# run the plugin in debug mode -/usr/libexec/netdata/plugins.d/node.d.plugin debug 1 X Y Z -``` - -`node.d.plugin` will run in `debug` mode (lots of debug info), with an update frequency of `1` second, evaluating only -the collector scripts `X` (i.e. `/usr/libexec/netdata/node.d/X.node.js`), `Y` and `Z`. -You can define zero or more modules. If none is defined, `node.d.plugin` will evaluate all modules available. - -Keep in mind that if your configs are not in `/etc/netdata`, you should do the following before running `node.d.plugin`: - -```sh -export NETDATA_USER_CONFIG_DIR="/path/to/etc/netdata" -``` - ---- - -## developing `node.d.plugin` modules - -Your data collection module should be split in 3 parts: - -- a function to fetch the data from its source. `node.d.plugin` already can fetch data from web sources, - so you don't need to do anything about it for http. - -- a function to process the fetched/manipulate the data fetched. This function will make a number of calls - to create charts and dimensions and pass the collected values to Netdata. - This is the only function you need to write for collecting http JSON data. - -- a `configure` and an `update` function, which take care of your module configuration and data refresh - respectively. You can use the supplied ones. - -Your module will automatically be able to process any number of servers, with different settings (even different -data collection frequencies). You will write just the work needed for one and `node.d.plugin` will do the rest. -For each server you are going to fetch data from, you will have to create a `service` (more later). - -### writing the data collection module - -To provide a module called `mymodule`, you have create the file `/usr/libexec/netdata/node.d/mymodule.node.js`, with this structure: - -```js -// the processor is needed only -// if you need a custom processor -// other than http -netdata.processors.myprocessor = { - name: 'myprocessor', - - process: function(service, callback) { - - /* do data collection here */ - - callback(data); - } -}; - -// this is the mymodule definition -var mymodule = { - processResponse: function(service, data) { - - /* send information to the Netdata server here */ - - }, - - configure: function(config) { - var eligible_services = 0; - - if(typeof(config.servers) === 'undefined' || config.servers.length === 0) { - - /* - * create a service using internal defaults; - * this is used for auto-detecting the settings - * if possible - */ - - netdata.service({ - name: 'a name for this service', - update_every: this.update_every, - module: this, - processor: netdata.processors.myprocessor, - // any other information your processor needs - }).execute(this.processResponse); - - eligible_services++; - } - else { - - /* - * create a service for each server in the - * configuration file - */ - - var len = config.servers.length; - while(len--) { - var server = config.servers[len]; - - netdata.service({ - name: server.name, - update_every: server.update_every, - module: this, - processor: netdata.processors.myprocessor, - // any other information your processor needs - }).execute(this.processResponse); - - eligible_services++; - } - } - - return eligible_services; - }, - - update: function(service, callback) { - - /* - * this function is called when each service - * created by the configure function, needs to - * collect updated values. - * - * You normally will not need to change it. - */ - - service.execute(function(service, data) { - mymodule.processResponse(service, data); - callback(); - }); - }, -}; - -module.exports = mymodule; -``` - -#### configure(config) - -`configure(config)` is called just once, when `node.d.plugin` starts. -The config file will contain the contents of `/etc/netdata/node.d/mymodule.conf`. -This file should have the following format: - -```js -{ - "enable_autodetect": false, - "update_every": 5, - "servers": [ { /* server 1 */ }, { /* server 2 */ } ] -} -``` - -If the config file `/etc/netdata/node.d/mymodule.conf` does not give a `enable_autodetect` or `update_every`, these -will be added by `node.d.plugin`. So you module will always have them. - -The configuration file `/etc/netdata/node.d/mymodule.conf` may contain whatever else is needed for `mymodule`. - -#### processResponse(data) - -`data` may be `null` or whatever the processor specified in the `service` returned. - -The `service` object defines a set of functions to allow you send information to the Netdata core about: - -1. Charts and dimension definitions -2. Updated values, from the collected values - ---- - -_FIXME: document an operational node.d.plugin data collector - the best example is the -[snmp collector](https://raw.githubusercontent.com/netdata/netdata/master/collectors/node.d.plugin/snmp/snmp.node.js)_ - - |