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Getting values from parameter store in AWS

Here is my code:
const AWS = require('aws-sdk');
const { Client } = require('pg');
function main() {
AWS.config.update({region:'eu-west-2'});
let db_user = {
Name: "postgres_db_user",
WithDecryption: false
};
let db_host = {
Name: "postgres_db_host",
WithDecryption: false
};
let db_database = {
Name: "postgres_db_name",
WithDecryption: false
};
let db_password = {
Name: "postgres_db_password",
WithDecryption: true
};
let db_port = {
Name: "postgres_db_port",
WithDecryption: false
};
let database_user_name;
let database_host;
let database_name;
let database_port;
let database_password;
let ssm = new AWS.SSM();
ssm.getParameter(db_user, function (err, data) {
if (err) {
console.log(err, err.stack);
} else {
database_user_name = data;
}
});
ssm.getParameter(db_host, function (err, data) {
if (err) {
console.log(err, err.stack);
} else {
database_host = data;
}
});
ssm.getParameter(db_database, function (err, data) {
if (err) {
console.log(err, err.stack);
} else {
database_name = data;
}
});
ssm.getParameter(db_password, function (err, data) {
if (err) {
console.log(err, err.stack);
} else {
database_password = data;
}
});
ssm.getParameter(db_port, function (err, data) {
if (err) {
console.log(err, err.stack);
} else {
database_port = data;
}
});
console.log(database_user_name);
console.log(database_host);
console.log(database_name);
console.log(database_password);
console.log(database_port);
let client = new Client({
user: database_user_name,
host: database_host,
database: database_name,
password: database_password,
port: database_port,
});
}
main();
The problem is that when I print the variables they are undefined, and I have no idea why. The SSM getParameter function is working because if I use the debugger, I see the values, but it doesn't seem to save the data variable in the variables for some strange reason.
If someone could help me as to why this code is printing undefined for the variables I would appreciate it.

I was drafting my answer when John commented :).
getParameter is async function and it's being executed while you are initializing the client with properties.
Here is some sample way of coding initialization.(not perfect but you can get the idea).
var AWS = require('aws-sdk');
AWS.config.update({ region: 'us-east-1' });
var ssm = new AWS.SSM();
function getParameter(param) {
return new Promise(function (success, reject) {
ssm.getParameter(param, function (err, data) {
if (err) {
reject(err);
} else {
success(data);
}
});
});
};
function main() {
let db_user = {
Name: "postgres_db_user",
WithDecryption: false
};
let database_user_name;
var promises = [];
promises.push(getParameter(db_user));
Promise.all(promises)
.then(function (result) {
database_user_name = result[0].Parameter.Value;
console.log(database_user_name);
let client = new Client({
user: database_user_name
//rest of the properties
});
//rest of the main() function code
})
.catch(function (err) {
console.log(err);
});
}
main();
Reference -
https://stackoverflow.com/a/44868681/5030709

How to test callback of function in Chai?

I am using Slack API and I want to test does it work fine with response status code. Here is sending function :
sendMsg(msg) {
return this.slack.webhook({text: msg}, (err, res) => {
if (err) {
throw err;
}
console.log(res.statusCode) // = 200
return res.statusCode;
});
}
And my test:
it('Checks connection with Slack', (() => {
let slack = new Slack();
let res = slack.sendMsg('test');
expect(res).to.equal(200);
}));
But ofc. it's giving me request object to slack. I want to wait for response object from slack API. Thanks in advance.

It looks like slack.webhook takes in a callback, which is how you retrieve the status. The problem is that the caller of sendMsg has no way of getting that status.
One way to solve this is to have sendMsg take in a callback:
sendMsg(msg, onStatusReceived) {
this.slack.webhook({text: msg}, (err, res) => {
if (err) {
throw err;
}
console.log(res.statusCode) // = 200
onStatusReceived(res.statusCode);
});
}
Then in your test, use done to end the test when the callback is invoked:
it('Checks connection with Slack', (done) => {
let slack = new Slack();
slack.sendMsg('message', status => {
expect(status).to.equal(200);
done();
});
});
Another way is to have sendMsg wrap slack.webhook in a promise, so the caller can do sendMsg().then(...).

one of the ways I handled a returning callback to test is as follows:
it('receives successful response', async () => {
nock('https://localhost')
.persist()
.log(console.log)
.post(‘/getData’, (unitData, callback) => {
return true;
})
.delayBody(1000)
.reply(200, {statusCode: 'Some Status'});
const getSomeData = await getResponse(unitData, function callBack(unitData, error, data){
expect(data.statusCode).to.be.equal(200);
}) })
getResponse Function (returning callback):
getResponse(unitData, function callBack(unitData, error, data){
try {
return request.post(unitData, function (err, resp) {
if (!err && resp.statusCode === 200) {
if (resp.body.error) {
return callback(obj, JSON.stringify(resp.body.error), null);
}
return callback(obj, null, resp);
} else {
if (err == null) {
err = { statusCode: resp.statusCode, error: 'Error occured.' };
}
return callback(obj, err, null);
}
});
} catch (err) {
return callback(obj, err, null);
}
}

Firebase Functions response returns null

tried get list of objects from s3(actually from wasabi) but in react always returns null
function code:
(using node 8)
exports.fetchWasabi = functions.https.onCall(() => {
const params =
{
Bucket: 'balde1-webcars',
};
s3.listObjectsV2(params, function(err, result) {
if (!err) {
console.log(result)
return result
} else {
console.log(err);
return err
}
});
});
react code:
componentDidMount(){
var Wasabi = firebase.functions().httpsCallable('fetchWasabi');
Wasabi().then(function(result) {
var res = result.data;
console.log(res)
}).catch(function(error) {
console.log(error)
});
}
when i check the log for the function i can see the result but it never reaches my browser apparently

You are not returning anything so you should add one more return like :
return s3.listObjectsV2(params, function(err, result) { ...

How to avoid a callback in promise

I am new to NodeJS and JavaScript. I am badly stuck in a problem:
I want to generate QR image of 'some text' and after generating it, I want to query my MySQL database and insert the image to database.
Problem is that QRCode.toDataURL of SOLDAIR module goes in running state and query is called before the QR image is returned from the .toDataUrl function.
Hence it results in error.
I tried everything, promises, nested promises, counters, if statements etc., but I am unable to find a solution.
My code:
router.post('/generateTicket', (req,res) => {
const query1 = `SELECT * FROM booking ORDER BY bookingID DESC LIMIT 1`;
const query2 = `INSERT INTO ticket (ticket_image,BookingID) SET ?`;
let bookingID;
let count;
let ticket_data = {};
Promise.using(mysql.getSqlConn(), conn => {
conn.query(query1).then(resultOfQuery1 => {
bookingID = resultOfQuery1[0].BookingID;
count = resultOfQuery1[0].PeopleCount;
console.log("ID = " + bookingID + " people count = "+count);
promiseToCreateQRcode().then(function (URLfromResolve) {
console.log("the url is " + URLfromResolve );
}).catch(function (fromReject) {
console.log("Rejected "+ fromReject);
}); // catch of promise to create QR
}).catch(err => {
res.json({ status: 500, message: 'Error Occured in query 1 ' + err });
}); // catch of query 1
});
});
var opts = {
errorCorrectionLevel: 'H',
type: 'image/png',
rendererOpts: {
quality: 0.3
}
};
let promiseToCreateQRcode = function () {
let QRImage;
return new Promise(function (resolve,reject) {
QRCode.toDataURL('text', function (err, url) {
if (err) throw err
console.log("\n"+url+"\n");
QRImage = url;
});
if (QRImage)
resolve(QRImage);
else
reject("error occured in url");
});
};
As u can see, the program jumps to if statement and the QR image is not generated yet, hence it goes in "reject":

Try this,
let promiseToCreateQRcode = function () {
return new Promise(function (resolve,reject) {
QRCode.toDataURL('text', function (err, url) {
if (err){
reject(err); // or some message
} else {
resolve(url);
}
});
});
};
This way promise will be resolved only when toDataURL returns QR image.

Have a look at How do I convert an existing callback API to promises?. You need to call resolve or reject in the asynchronous callback!
function promiseToCreateQRcode() {
return new Promise(function(resolve,reject) {
QRCode.toDataURL('text', function (err, url) {
if (err) {
reject(err);
} else {
console.log("\n"+url+"\n");
resolve(url);
}
});
});
}
Using this extra QRImage variable like you did cannot work.

Use ldapjs with promise

I want to convert the following code to use promise. It is working and output a user's attributes within the active directory.
var client = ldap.createClient({
url: ldap_url
});
client.bind(ldap_username, ldap_password, function (err) {
client.search(ldap_dn_search, opts, function (err, search) {
search.on('searchEntry', function (entry) {
var user = entry.object;
// It is working!!!. It outputs all user attributes.
console.log(user);
});
});
});
The following is my attempt, butit doesn't output anything.
var Promise = require('promise');
var client_bind = Promise.denodeify(client.bind);
var client_search = Promise.denodeify(client.search);
client_bind(ldap_username, ldap_password)
.then(function(err){
client_search(ldap_dn_search, opts)
.then(function(search){
var search_on = Promise.denodeify(search.on);
search_on('searchEntry')
.then(function(entry){
var user = entry.object;
// It doesn't output anything !!!
console.log(user);
});
});
});

I had the same problem.
Search emits events, so we need something that processes them and passes further along the chain.
Here is piece of code, that works for me:
var ldap = require('ldapjs');
var promise = require('bluebird');
var client = ldap.createClient({url: app.settings['ldap']['server']});
var uid;
promise.promisifyAll(client);
function searchPromise(res, notfoundtext) {
return new Promise(function(resolve, reject) {
var found = false;
res.on('searchEntry', function(entry) {
found = true;
resolve(entry);
});
res.on('error', function(e) {
reject(e.message);
});
res.on('end', function() {
if (!found) {
reject(notfoundtext);
}
});
});
}
client.searchAsync(app.settings['ldap']['baseDn'], {filter: '(mail='+credentials.email+')', scope: 'sub'})
.then(function(res) {
return searchPromise(res, 'User isn\'t exists.');
})
.then(function (entry) {
uid = entry.object.uid;
return client.bindAsync(entry.object.dn, credentials.password);
})
.then(function() {
return client.searchAsync('cn='+app.settings['ldap']['group']+',cn=groups,'+app.settings['ldap']['baseDn'], {scope: 'sub', filter: '(memberUid='+uid+')'});
})
.then(function(res) {
return searchPromise(res, 'User is not in group ' + app.settings['ldap']['group']);
})
.then(function() {
console.log('All is ok');
})
.catch(function(message) {
console.log('Error:' + message);
});
Immediately after the search I add one more step that catches the events, processes them, and passes it further along the chain. This makes the function searchPromise.
Good luck coding )

Most likely those methods do require to be called on client as a context, so you will need to bind() them before passing them to Promise.denodeify:
var client_bind = Promise.denodeify(client.bind.bind(client));
var client_search = Promise.denodeify(client.search.bind(client));
Also, a proper use of promises would look like this:
client_bind(ldap_username, ldap_password).then(function() {
return client_search(ldap_dn_search, opts);
// ^^^^^^ always return something from the callback
}).then(function(search) { // flatten your chain
return Promise.denodeify(search.on).call(search, 'searchEntry');
// ^^^^^^ an alternative to `bind`
}).then(function(entry){
var user = entry.object;
console.log(user);
}).catch(function(err) { // always catch errors!
console.error(err);
});

Using Bluebird Promises, the easy way to do this is to create your client normally, and then run the promisifyAll() on the client.
var ldap = require('ldapjs');
var Promise = require('bluebird');
var client = ldap.createClient({
url: 'ldap://my-server:1234',
});
Promise.promisifyAll(client);
Now you can call client.addAsync() and client.searchAsync() and such.
client.bindAsync(secUserDn, secUserPassword)
.then(doSearch) // if it works, call doSearch
.catch(function (err) { // if bind fails, handle it
console.error('Error on bind', err)
});
function doSearch(data) {
client.searchAsync('CN=A Test,OU=Users,DC=website,DC=com', options)
.then(function (data) { // Handle the search result processing
console.log('I got a result');
})
.catch(function (err) { // Catch potential errors and handle them
console.error('Error on search', err);
});
}

i had the same issue here but i solved it by adding promise and resolve the response without using bluebird, this is an exemple of my code :
async getLdapUser(username: any): Promise<any> {
let myPromise = new Promise<boolean>((resolve, reject) => {
console.log('ssssssssss', username);
const adSuffix = 'OU=xxxx,OU=xxxxx,DC=xxxxxxx,DC=xxxxxx';
const password = 'xxxxxxxxxxxxx';
// Create client and bind to AD
const client = ldap.createClient({
url: 'ldap://1.1.1.1:389',
});
// promise.promisifyAll(client);
let resp = false;
// console.log(client);
client.bind('userTest', password,(err: any) => {
console.log('RESP', resp);
if (err) {
console.log('Error in new connetion ' + err);
} else {
/*if connection is success then go for any operation*/
console.log('Success');
const searchOptions: {} = {
scope: 'sub',
filter: '(sAMAccountName=' + username + ')',
attributes: ['sAMAccountName'],
};
client.search(adSuffix, searchOptions, (err: any, res: any) => {
assert.ifError(err);
res.on('searchEntry', (entry: any) => {
resp = true;
});
res.on('error', (error: any) => {
console.log('err');
reject(error.message);
});
await res.on('end', (result: any) => {
resolve(resp);
});
});
}
});
});
return myPromise;
}