plugin-odem-etcd

connecting Hitchy's ODM with etcd cluster

License

MIT

About

Hitchy is a server-side framework for developing web applications with Node.js. Odem is a plugin for Hitchy implementing an object document management (ODM) using data backends like regular file systems, LevelDBs and temporary in-memory databases. Accessing either backend requires some adapter.

This package is implementing an adapter for storing data in an etcd-based cluster.

Installation

Execute the following command in the folder of your Hitchy-based application to install this adapter:

npm i @hitchy/plugin-odem-etcd

The adapter depends on @hitchy/plugin-odem, which in turn depends on @hitchy/core. Either dependency must be installed manually as well:

npm i @hitchy/core @hitchy/plugin-odem

Usage

Select an instance of this backend as default adapter in your application's configuration by creating a file config/database.js with content similar to this:

const File = require( "fs" );

module.exports = function() {
    return {
        database: {
            default : new this.runtime.services.OdemAdapterEtcd( {
                hosts: [
                    "https://10.0.1.1:2379",
                    "https://10.0.1.2:2379",
                    "https://10.0.1.3:2379",
                ],
                retry: false,
                credentials: {
                    rootCertificate: File.readFileSync( "path/to/ca.pem" ),
                    certChain: File.readFileSync( "path/to/cert.pem" ),
                    privateKey: File.readFileSync( "path/to/key.pem" ),
                },
                auth: { username: "john.doe", password: "secret" },
                prefix: "common/prefix/user/can/readwrite",
            } ),
        },
    };
};

Most of provided options are forwarded to instance of Etcd3 created internally.

• hosts is a list of endpoint URLs of etcd cluster to connect with.

  The given example illustrates encrypted connections via https using IP addresses. Depending on your setup using host names may be available, as well.

• retry is a boolean controlling whether client should retry queries when one of the tested nodes in list isn't available or is having temporary issues.

  This feature is enabled by default and so you don't need to provide it here unless you want to disable it.

• credentials is an object selecting a client TLS certificate for authenticating with the cluster.

  Using this feature is optional. However, using this might require connection encrypted via https, only.

• auth is an object providing authentication data for role-based access control (RBAC). It contains properties username and password containing either information in cleartext.

  It's okay to omit this when connecting with a cluster that doesn't use RBAC. You should consider RBAC when connecting different applications to a single etcd cluster.

In opposition to those, the following options are consumed by this adapter:

• prefix defines a common prefix to use on every read/write operation of current application.

  This defaults to hitchy-odem when omitted. We suggest using Unix-style path names. Leading and trailing forward slashes are ignored.