How to write azure functions which will use express api

Question

I have a azure function, In index.js i have the following code

module.exports = function (context, req) {

const createHandler = require('azure-function-express').createHandler;
const app = require('express')();

app.get("/home", (req, res) => {
    const y = { "name": "name", "dob": "ddmmyyyy" }
    context.res = y
    context.done()
});
module.exports = createHandler(app);

context.done();
};

i have function.json :

    {
  "bindings": [
    {
      "authLevel": "anonymous",
      "type": "httpTrigger",
      "direction": "in",
      "name": "req",
      "route": "{*segments}"
    },
    {
      "type": "http",
      "direction": "out",
      "name": "res"
    }
  ],
  "disabled": false
}

i have the above files in my azure function but i am not able get any output i just a blank page if i hit the api end point. i have to use express to handle many other end points is there any way to handle in azure functions.

when i use nodejs local application setup, i am able to use express and handle many api end points with in a single module is that possible in azure functions? or i have to use different functions for each end point

Answer 1

See code below. We can use Azure function as a common express app.

const createHandler = require('azure-function-express').createHandler;
const app = require('express')();

app.get("/home", (req, res) => {
    res.json({ "name": "name", "dob": "ddmmyyyy" });
});

app.get("/work", (req, res) => {
    res.json({ "name": req.query.name, "dob": "ddmmyyyy" });
});

module.exports = createHandler(app);

module.exports = function (context, req) and context.done() are no longer useful if azure-function-express is in use. If you want to use other method of context, use req.context instead. See azure-function-express module doc.

Besides, Azure function has a prefix "api" in route by default, if you don't need it(like code above), change it to empty your host.json.

If your function runtime is ~2(beta).

{
  "version": "2.0",
  "extensions": {
    "http": {
        "routePrefix": ""
    }
  }
}

Else in ~1

{
    "http": {
        "routePrefix": ""
    }
}

Answer 2

I have also use try this azure-function-express package but its still in the development and need a-lot of improvement. The best package i found is Azure AWS Severless Express

Package. Its very easy to use and compatible. You can easily use the Express with azure functions