authenticate.js

var passport = require('passport');
var LocalStrategy = require('passport-local').Strategy;
var User = require('./models/user');
var JwtStrategy = require('passport-jwt').Strategy;
var ExtractJwt = require('passport-jwt').ExtractJwt;
var jwt = require('jsonwebtoken');
const config = require('./config/default');

passport.use(new LocalStrategy(User.authenticate()));
passport.serializeUser(function(user, done) {
    done(null, user.id);
});   
passport.deserializeUser(function(id, done) {
    User.findById(id, function(err, user) {
        done(err, user);
    });
});

exports.getToken = (user) => {
    return jwt.sign(user, config.secretKey,
        {expiresIn: 36000});
};

var opts = {};
opts.jwtFromRequest = ExtractJwt.fromAuthHeaderAsBearerToken();
opts.secretOrKey = config.secretKey;

exports.jwtPassport = passport.use(new JwtStrategy(opts,
    (jwt_payload, done) => {
        console.log("JWT payload: ", jwt_payload);
        User.findOne({_id: jwt_payload._id}, (err, user) => {
            if (err) {
                return done(err, false);
            }
            else if (user) {
                return done(null, user);
            }
            else {
                return done(null, false);
            }
        });
    }));

exports.verifyUser = passport.authenticate('jwt', {session: false});