Unable to make PUT request to Cloudant-bluemix database using Nodejs-express - node.js

Question

I'm trying to implement a Password reset. So I'm taking the phone number of the user, getting the document from the database using the phone number to find it, and I'm taking the new password and trying to update the corresponding document using a PUT request in my Cloudant database.
app.post('/pass_rst', function(req,response){
var log='';
//log is just for me to see what's happening
var phone= req.body.phone;
log+=phone+'\n';
db.find({selector:{'phone':phone}}, function(err, result){
if(err){
throw err;
}
if(result.docs.length==0){
response.send('User doesnt exist');
}else{
var existing_data=result.docs[0];
log+=JSON.stringify(existing_data)+'\n';
var upd_pswd= req.body.new_password;
log+=upd_pswd+'\n';
var new_data=existing_data;
new_data.password=upd_pswd;
log+=JSON.stringify(new_data)+'\n';
var id= result.docs[0]._id;
log+=id+'\n';
//make PUT request to db
var options={
host:dbCredentials.host,
port:dbCredentials.port,
path:'/'+dbCredentials.dbName+'/'+id,
//url: dbCredentials.url+'/'+dbCredentials.dbName+'/'+id,
method:'PUT',
json:new_data,
headers:{
'Content-Type':'application/json',
'accept':'*/*'
}
};
log+=JSON.stringify(options)+'\n';
var httpreq= http.request(options);
//log+=JSON.stringify(httpreq);
httpreq.on('error', function(e){
response.send('Error'+e.message);
});
response.send(log+'\n\n\nUpdated');
}
});
});
dbCredentials is defined above as follows:
dbCredentials.host = vcapServices.cloudantNoSQLDB[0].credentials.host;
dbCredentials.port = vcapServices.cloudantNoSQLDB[0].credentials.port;
dbCredentials.user = vcapServices.cloudantNoSQLDB[0].credentials.username;
dbCredentials.password = vcapServices.cloudantNoSQLDB[0].credentials.password;
dbCredentials.url = vcapServices.cloudantNoSQLDB[0].credentials.url;
I've tried tinkering around with it, but in the best case scenario, I don't get an error and I see "Updated" but nothing actually happens in the database. Sometimes I get an error saying : 502 Bad Gateway: Registered endpoint failed to handle the request.
If you see what's going wrong, please let me know. Thank you.
This is the documentation on how to update documents in cloudant
UPDATE
Updating a document
PUT /$DATABASE/$DOCUMENT_ID HTTP/1.1 { "_id": "apple", "_rev":
"1-2902191555", "item": "Malus domestica", "prices": {
"Fresh Mart": 1.59,
"Price Max": 5.99,
"Apples Express": 0.79,
"Gentlefop's Shackmart": 0.49 } }
To update (or create) a document, make a PUT request with the updated
JSON content and the latest _rev value (not needed for creating new
documents) to https://$USERNAME.cloudant.com/$DATABASE/$DOCUMENT_ID.
If you fail to provide the latest _rev, Cloudant responds with a 409
error. This error prevents you overwriting data changed by other
processes. If the write quorum cannot be met, a 202 response is
returned.
Example response: { "ok":true, "id":"apple",
"rev":"2-9176459034" }
The response contains the ID and the new revision of the document or
an error message in case the update failed.

Answer 1

I am using bluemix -nodejs and cloudant. The best way that worked for me to do the update is to use the nano package for db interaction from node.js.
You can refer to the post here:
The summary is - By making use of nano api, you can easily update the record. You need to make sure to use - the _id and the right _rev number, while you use nano. This inturn uses PUT Method underneath.
Updating and Deleting documents using NodeJS on Cloudant DB
When you are including nano, make sure to update the package.json to have the nano dependency added. Let me know if you have further questions on the update/delete

Answer 2

When using the cloudant node.js module there is no separate update function.
You need to use the db.insert function also for the update with the right doc revision, so you need to read the latest revision before the insert.
https://github.com/apache/couchdb-nano#document-functions
"and also used to update an existing document, by including the _rev token in the document being saved:"
// read existing document from db
db.get(key, function(error, existing) {
if (!error)
// use revision of existing doc for new doc to update
obj._rev = existing._rev;
// call db insert
db.insert(obj, key, cb);
});