Server Health


Allows to easily add a /health endpoint to a Fastify, Restify, Express, Hapi
or native node http server returning vital information about a service.

Example output

``json
{
"status": "ok", // overall server status
"uptime": 3714, // uptime in seconds
"upSince": "2017-05-12T03:13:06.462Z",
"service": { // package.json meta data
"name": "foobarbaz-server",
"description": "Foo Bar Baz Server",
"version": "0.14.0",
"repository": {
"type": "git",
"url": "git@example.com:foobarbaz-server.git"
}
},
"connections": { // plugable connection checks
"mongodb": "ok",
"redis": "ok",
"rabbitmq": "ok"
},
"env": {
"nodeEnv": "local",
"nodeVersion": "v0.10.37",
"processName": "foobarbazd",
"pid": 10329,
"cwd": "/Users/example/foobarbaz-server"
},
"git": {
"commitHash": "c5d7c311ac8b5de7e309e18b821225d471c2cf1d",
"branchName": "server-health-integration",
"tag": null
}
}
`

Usage

$3

See example/server.js for a complete example. Also check the tests for how to use this with hapi and express.

`js
const restify = require('restify');
const serverHealth = require('server-health');

serverHealth.addConnectionCheck('database', function () {
// determine whether database connection is up and functional
return true;
});
serverHealth.addConnectionCheck('rabbitmq', function () {
// determine whether RabbitMQ connection is up and functional
return true;
});
serverHealth.addConnectionCheck('redis', function () {
// determine whether Redis connection is up and functional
return true;
});
const server = restify.createServer();
serverHealth.exposeHealthEndpoint(server);
server.listen(8080, function() {
console.log('Listening on port 8080');
});
`

For frameworks other than restify (default) specify the used framework:

`js
const fastify = require('fastify');

const server = fastify();
serverHealth.exposeHealthEndpoint(server, '/health', 'fastify');
server.listen({port: 8080}, function() {
console.log('Listening on port 8080');
});
`

$3

After adding the server info health endpoint to a service you can do a quick check
on its status using curl and jq:

`bash
> curl -s http://localhost:8080/health | jq '.status'
"ok"
`

$3

Instead of filtering the whole response on the client the library also supports
filtering server side by specifying a "filter" query string parameter.

Multiple properties can be queried by separating them by comma: filter=status,env.nodeEnv

`bash
> curl -s http://localhost:8080/health?filter=status
{"status":"ok"}
`

$3

For services that do not have an existing Restify, Express, or Hapi Server, you can create a
native Node HTTP Server that only has one route, that also provides the same health
checks as Restify, Express, and Hapi servers.

`javascript
const serverHealth = require('server-health');
serverHealth.addConnectionCheck('database', function () {
// determine whether database connection is up and functional
return true;
});
const options = {
endpoint: '/health', // optional and will default to /health
};
const nodeServer = serverHealth.createNodeHttpHealthCheckServer(options);
nodeServer.listen(8080);
``