nodejs httprequest with data - getting error getad

问题:

Update - Answered by self

I see one has to make sure that the DNS is resolved properly from the machine, check out the node documentation to make sure that domain is resolvable.

Original Question

i am writing a nodes based program,in which the user can ask me to do a httprequest on their behalf {off course they provide me with some data, and method to call with} but every time i do a httprequest it gives me an error

getaddrinfo ENOENT this is how my code looks

function makehttprequest(deviceid, httpaction, httppath,methods, actiondata, callback) {
console.log('we are here with httpaction' + httpaction + ' path ' + httppath + ' method ' + methods + ' action data ' + actiondata);
 //do the http post work, get the data, and call the callback function with return data
 var options = {
   host: httpaction,
   port: 80,
   path: httppath,
   method: methods
 };

    try {
      var req = http.request(options, function(res) {
        console.log('STATUS: ' + res.statusCode);
        console.log('HEADERS: ' + JSON.stringify(res.headers));
        res.setEncoding('utf8');
        res.on('data', function (chunk) {
          console.log('BODY: ' + chunk);
        });
      });
    } catch(e) {
      console.log('error as : ' + e.message);
    }

    req.on('error', function(e) {
      console.log('problem with request: ' + e.message);
    });

    // write data to request body
    console.log('writing data to request ..');
    req.write(actiondata);
    console.log('finished writing data to request…');
    req.end();
    console.log('request ended…');
}

回答1:

I've seen this happen when your host (which you pass in as httpaction) has the scheme (so "http://") in front of it. Your host should strictly be the domain like "www.google.com" not "http://www.google.com" or "www.google.com/hello-world" or "http://www.google.com/hello-world".

Keep it just the domain.

Here's an example: http://allampersandall.blogspot.com/2012/03/nodejs-http-request-example.html

回答2:

The problem can also happen if you have a trailing slash:

Good: "www.google.com"

Bad: "www.google.com/"

回答3:

Avoid all of these hostname/protocol/port/slash problems by using the request module instead of http

https://github.com/mikeal/request

回答4:

I was getting [Error: Getaddrinfo ENOENT], but it was right after getting [Error: connect EMFILE]; since I am doing load tests with thousands of clients the EMFILE error (the root cause) was being opaqued. The solution was the same as for EMFILE: increase the number of file descriptors. Just adding it here for completeness in case anyone else has the same problem.

回答5:

I hit this again today for a silly mistake. This was because port number was put as part of the hostname.

// wrong. gets error getaddrinfo ENOENT
var options = {
  hostName: 'localhost:1337',
  ....
}

// correct
var options = {
    hostname: 'localhost',
    port: 1337,
};

回答6:

I was getting this error when calling server.listen(PORT, HOST); where HOST could not be resolved back to the local machine.

Once I changed this back to a hostname/domain name/ip that the local machine resolved to, this error went away.

Since I was trying to connect via a hostname for dev purposes I added an entry to my hosts file with the desired hostname and ensured that this matched the hostname passed to server.listen()

回答7:

If all your code seems to be alright and you're still get the same error, which was my case, the solution was checking the nameservers on my /etc/resolv.conf file.

I added Google's nameserver at the beginning of my resolv.conf file (8.8.8.8) and the code started working just fine once again, no more error.

It's worth noticing that this error started happening on me on Feb. 4th 2015 after I ran an sudo apt-get upgrade, my node js must have been updated and a bug introduced which seemed to be incompatible with the nameservers I had.

At first I checked if I was having any DNS issues by fetching the URL I needed using wget on the command line, I got the contents of the target url fine so I didn't think it was actually a DNS issue, but it was.

回答8:

I had a similar issue but running as a AWS Lambda function, so in case someone is having this issue with Lambda functions this is how I got it resolved.

• Give your Lambda function a VPC.
• Select at least 2 Subnets.
• And select a Security Group.

I spent a day until I found this fix, hope it helps someone else.