CODEWITHSUNDEEP
javascriptnode.jsamazon-web-services
Dcook
Dcook

Reputation: 961

how to access aws parameter store value from Nodejs and use it later

I have a requirement where I want to access parameter store value and then use that later. This is how I am doing:

var options = {
    Name: 'SecretAccessKey_temp',
    WithDecryption: true
};

var secreretAccesKeyParam = ssm.getParameter(options).promise();

secreretAccesKeyParam.then(function (data, err) {
    if (err) console.log(err, err.stack);
    else {
        const secretAccessKey = data.Parameter.Value
        console.log(secretAccessKey)
   
       
    }
});

This is giving me value but if I want to access secretAccessKey variable outside of this it's giving me 'undefined'. Can anyone please help me out to access this secretAccessKey variable outside of this function?

Upvotes: 2

Views: 3199

Answers (2)

jbg
jbg

Reputation: 116

As your variable secreretAccesKeyParamis a promise, you won't be able to access the context (e.g. secretAccessKey) of your promise handler (e.g. function (data, err) {...}). By definition of promise doing so :

const myPromise = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve('foo');
  }, 300);
});
var myRes = 'bar';
myPromise.then(dunction (data, err) {
  myRes = data;
  console.log(myRes); // executed asynchronously
});
console.log(data); // executed sychronously so printed first. myRes value is still 'bar'.

Would give you the output :

'bar'
'foo'

What you might want to do could be using an async function if you want to handle things as if they were synchronous.

var options = {
    Name: 'SecretAccessKey_temp',
    WithDecryption: true
};

var secreretAccesKeyParam = ssm.getParameter(options).promise();

(async () => {
  try {
    const data = await secreretAccesKeyParam;
  } catch (err) {
    console.log(err, err.stack);
  }

  const secretAccessKey = data.Parameter.Value;
  console.log(secretAccessKey);
  ... // any action with your secret access key
})();

Or if you are already using handler function later :

let _secretAccessKey;
const getSecretAccessKey = async () => {
  if (!_secretAccessKey) {
    try {
      const data = await secreretAccesKeyParam;
    } catch (err) {
      console.log(err, err.stack);
      return null;
    }
    _secretAccessKey = data.Parameter.Value;
  }
  return Promise.resolve(_secretAccessKey);
}

...

async function mySuperHandler() {
  const secretAccessKey = await getSecretAccessKey();
  // do something with the secret
}

Upvotes: 1

Nguyen Kim Bang
Nguyen Kim Bang

Reputation: 41

How about set it as env ? Im currently use this method, but you have to make sure env is set before use it.

secreretAccesKeyParam.then(function (data, err) {
  if (err) console.log(err, err.stack);
  else {
    process.env.secretAccessKey = data.Parameter.Value;
    const secretAccessKey = process.env.secretAccessKey;
    console.log(secretAccessKey);
  }
});

Upvotes: 0

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