eureka-client-js

Usage

Install via npm+git: npm install hexa1/eureka-client-js --save.

import EurekaClient from 'eureka-client-js';

const myClient = new EurekaClient({
  // ... options, see below
});

myClient.register();

Options

The following options are available:

Option	Type	Description	Required	Default value
eurekaHost	string	host:port of your Eureka registry	yes
instance	object	see Instance Options below	yes
registerRetryInterval	number	how long to wait after a failed registration before attempting again, in seconds	no	5
retryRegisterAfter	number	how many failed heartbeat attempts can occur before attempting to re-register	no	3
heartbeatInterval	number	how often to send a heartbeat, in seconds	no	5
registryInterval	number	how often to fetch the registry, in seconds	no	15
logLevel	string	see winston logging levels	no	info

Instance Options

The instance object should conform to the Eureka XSD spec: https://github.com/Netflix/eureka/wiki/Eureka-REST-operations.

The only difference is that you should pass instanceId inside the instance object. This value isn't passed to Eureka during registration but it is used for crafting the URLs when making requests to Eureka.

EurekaClient class methods

The following methods are available after instantiating a new EurekaClient object:

• register(): registers with the eureka registry. will continue to try to re-register if registration fails
• stopRegisterRetry(): if registration fails it will automatically retry itself according to the registerRetryInterval option. Use this if you want to stop that retry loop.
• deregister(): deregisters with the eureka registry
• fetchRegistry(): gets the latest list of instances from the eureka registry, stores in internal cache
• startRegistryFetcher() - runs fetchRegistry() at the interval specified in options
• stopRegistryFetcher() - stops fetching the registry
• getInstanceByAppId(appId) - gets the first available instance of an app on the registry
• sendHeartbeat() - sends a heartbeat for this service
• startHeartbeats() - runs sendHeartbeat() at the interval specified in options
• stopHeartbeats() - stops sending heartbeats
• middleware() - see Middleware

Middleware

This is an express-compatible middleware that provides endpoints used by the Eureka server for determining the health of the service.

The following endpoints are provided:

• /info
• /health
• /metrics
• /env

Usage

const app = express();
const myClient = new EurekaClient({
  // ...options
});

app.use(myClient.middleware());

Testing

npm run test

npm run coverage to get code coverage stats

Development

Please lint all code before committing: npm run lint.

The package needs to be built and the built files committed: npm run build.

TODO

• Allow passing a custom winston logging transport, e.g. for remote logging