@greenrenge/gracefully

A lightship module for support kubernetes liveness and readiness

Description

This module is a simple wrapper of the original lightship library which helps to easily initialize the ready callback functions for multiple source of ready interconnected services being used by the application (eg. database) or configuration loading of the application.

Features

• add createReadiness which help to split lightship signalReady to multiple functions
• server exposes on paths /health /live and /ready as the original lightship does but listen on port 13000 by default
• add enableLog option to print lightship logs
• add randomPortOnLocal to reserve random port behavior when the process is run on local as the original lightship does, default to false

Install

npm install --save @greenrenge/gracefully

Usage

Readiness

import createLightship from "@greenrenge/gracefully"

const { createReadiness } = createLightship()
const [mongooseDbReady, expressReady, senecaReady] = createReadiness(3)

// for mongoose connection
mongoose.connect(/* connectionString */)
mongoose.connection.on("connected", () => mongooseDbReady())

// for express
const app = express()
app.listen(3000, () => expressReady())

// for seneca
require("seneca")({ some_options: 123 })
  .use("community-plugin-1", { some_config: SOME_CONFIG })
  .use("community-plugin-2")
  .listen(/* ... */)
  .client(/* ... */)
  .ready(() => senecaReady())

in case of making service back to not ready state, we get functions by 2 ways ..

const [mongooseDbReady] = createReadiness()

// first way, return from ready function call
const mongooseNotReady = mongooseDbReady()
mongooseNotReady()

// second way, by property `toNotReady` of ready function
mongooseDbReady.toNotReady()

License

MIT © Greenrenge