How to make a POST api call to google endpoints using the ardunio WiFiClient

Question

i'm working on an iot project with the ESP8266 wifi module. I've been able to successfully connect it to the internet and make an GET request to a html page using this tutorial provided by adafruit. but I seem to be having difficulties integrating it with the api endpoints that I have running on the google developer console.

Here's the potion of the code i'm having problems with

const char* Host = "www.my_app_id.appspot.com";
String PostData = "clientId=&fanId=&kueliiKey=";
String url = "/_ah/api/fan/v1/register?";
Serial.print("Requesting URL: ");
Serial.println(url);
//Connect to the client and make the api call
if (client.connect(Host, httpPort)) {
    client.println("POST " + url + " HTTP/1.1");
    client.println("Host: "+ (String)Host);
    client.println("User-Agent: Arduino/1.0");
    client.println("Connection: close");
    client.print("Content-Length: ");
    client.println(PostData.length());
    client.println();
    client.println(PostData);
    delay(500);
}
//Read all the lines of the reply from server and print them to Serial          
while (client.available()) {
    String line = client.readStringUntil('\r');
    Serial.print(line);
}

//Serial.println();
Serial.println("closing connection");

I'm able to connect but I keep on getting a 404 error

lloc\umm_malloc.c
HTTP/1.1 404 Not Found
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: Fri, 01 Jan 1990 00:00:00 GMT
Date: Tue, 22 Mar 2016 12:08:06 GMT
Vary: X-Origin
Content-Type: text/html; charset=UTF-8
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
Server: GSE
Accept-Ranges: none
Vary: Origin,Accept-Encoding
Connection: close

Not Found
closing connection;

What I have in

String url = "/_ah/api/fan/v1/register?";

might be wrong, but I've double checked and using http://hurl.it and the api call works and returns what I want image of successful request any insight on this would be greatly appreciated.

Thanks.

score 4 · Accepted Answer · answered Mar 23 '16 at 07:33

After a ton of tries i realized what was wrong and here's how i fixed it.

I changed my url to https apparently endpoints highly favor https now

www.my_app_id.appspot.com became https://my_app_id.appspot.com;
Then i had to change my port to 443 and attach postdata to the calls with the POST header url path.

client.println("POST " + url + " HTTP/1.1")->client.println("POST " + url + + Postdata +" HTTP/1.1");
Finally i had to change from using WifiClient to WiFiClientSecure.

Hope this helps someone :)

How to make a POST api call to google endpoints using the ardunio WiFiClient

1 Answers1