This is a convenience package for starting a express API with security, health checks, process exits etc.
This is a convenience package for starting a express based API server with
1. General API Security - (helmet based)
2. Health checks - K8S Health Probes
3. Process exits listeners - Your API server should shutdown as gracefully as possible when it receives any shutdown signals from OS.
4. Include your API documentation - Swagger UI express.
5. Singleton DI container - possibly the best pattern to follow, yet completely flexible and ignorable.
6. Creator pattern - don't use new keyword, this helps in writing better unit tests and mockable classes and features.
1. Please find example code usage in examples folder
``javascript
import { ApplicationBuilder, ApplicationStartupStatus, ApplicationTypes, Convenience } from "../../dist/src/index.js";
import * as OpenApiDefinition from "./api-def.json" with { type: "json" };
const applicationName = "Test Simple App";
const app = new ApplicationBuilder(applicationName, OpenApiDefinition);
const utilities = new Convenience();
function shouldCompress(req, res) {
if (req.headers['x-no-compression']) {
// don't compress responses with this request header
return false
}
// fallback to standard filter function
return true
}
async function AppStartUp(rootRouter, DIContainer, application) {
//Connect to DB or create DB Pool
//Apply Migrations
//Register Routes,Middleware,etc
DIContainer.registerInstance("msg", { message: "Hello from DI" }); //Simulate things stored in DI container
rootRouter
.get("/", (req, res) => {
res.send(req.DIProp.fetchInstance("msg").message);
})
.post("/", (req, res) => {
console.log(req.body);
})
.get("/error", (req, res) => {
throw new Error("This is an error to validate final 'ErrorResponseTransformer' error handling of library");
});
//Configure your application.
const apiDocs = utilities.swaggerAPIDocs(OpenApiDefinition);
application.overrideAppPort(8080) //override the default port 8080(Default 3000)
.overrideHealthPort(8081) //override the default health port 8081(Default 5678)
.registerApplicationHandler(utilities.helmetMiddleware(), "*", 1, ApplicationTypes.Both) //register helmet middleware for both application and health
.registerApplicationHandler(utilities.bodyParserURLEncodingMiddleware(), "*", 2, ApplicationTypes.Main) //register body parser url middleware for application
.registerApplicationHandler(utilities.bodyParserJSONEncodingMiddleware({ limit: '50M' }), "*", 3, ApplicationTypes.Main) //register body parser json middleware for application
.registerApplicationHandler(apiDocs.router, apiDocs.hostingPath, 4, ApplicationTypes.Main) //register api docs
.registerApplicationHandler(utilities.injectInRequestMiddleware("DIProp", DIContainer), "*", 5, ApplicationTypes.Main) //register DI container middleware
.registerApplicationHandler(utilities.compressionMiddleware({ filter: shouldCompress }), "*", 6, ApplicationTypes.Main) //register compression middleware
.registerApplicationHandler(utilities.staticMiddleware("examples\\simple-express\\public"), "/public", 7, ApplicationTypes.Main) //register static file serving middleware
.overrideCatchAllErrorResponseTransformer((req, error) => ({ //override the default catch all error response transformer
path: req.path,
status: 500,
body: { message: error.message }
}))
return {
status: ApplicationStartupStatus.UP, // Indicates startup was successful
data: { message: "Connected to database" } // Additional data to be returned(Optional)
};
}
app.overrideStartupHandler(AppStartUp)
.start()
.then(() => console.log(${applicationName} started successfully.))
.catch(console.error);
//*
// You can wait for your application to be called by process exit signal
// OR
// If you are done call the Dispose method to stop the application
// await app[Symbol.asyncDispose](); //stop the application and release all resources
//*
``
1. Authors :heart: for Open Source.
1. New ideas/techniques are welcomed.
2. Raise a Pull Request.
This project is contribution to public domain and completely free for use, view LICENSE.md file for details.