Express healthchecker

Expose an express service health status.

Use

Install with:

npm install --save express-healthchecker

Write some health checks:

/*
*   A healthCheck is an object with the following properties:
*   - `name` (stirng): the name of the health check
*   - `checkHealth` (function): a function that returns (a promise to) a
*     healtResult
*
*   A healthResult is an object with the following properties:
*   - `isHealthy` (boolean): indicates the health status
*   - `details` (any) (optional): contains details about a check
*/
module.exports = {
    name: "myHealthCheck",
    checkHealth: () => {
        return Promise.resolve({
            isHealthy: false,
            details: "Problems occurred"
        });
    }
};

Use them in your express app:

const express = require("express");
const {healthRoute} = require("express-healthchecker");

const myHealthCheck = require("src/healthChecks/myHealthCheck");

express()
    .get("/health", healthRoute({
        healthChecks: [myHealthCheck],
        accessToken: process.env.HEALTH_ROUTE_ACCESS_TOKEN
    }));

When accessing the /health resource all checks are run and the resource responds with:

• 200 Ok if the service is healthy (all checks pass)
• 503 Service Unavailable if the service is unhealthy (some checks fail)

The body of the response is a JSON object with property isHealthy indicating the health status.

If an access_token matching the accessToken passed as option to healthRoute is provided in the querystring of the request, additional details are returned in the response.

Example requests/responses:

GET /health

200 OK
{
    "isHealthy": true
}

---

GET /health

503 Service Unavailable
{
    "isHealthy": false
}

---

GET /health?access_token=valid_access_token

200 OK
{
    "isHealthy": true,
    "details": {
        "myHealthCheck": {
            "isHealthy": true
        }
    }
}

---

GET /health?access_token=valid_access_token

503 Service Unavailable
{
    "isHealthy": false,
    "details": {
        "myHealthCheck": {
            "isHealthy": false,
            "details": "Problems occurred"
        }
    }
}

Contributing

See CONTRIBUTING.