ESP8266HTTPClient POST doesn't work and returns -1 as status code

[vitornilson1998]

I am trying to do a POST request to my Webserver that is running in a Kubernetes cluster.

If I do this request in postman, works fine:

When I try to do this request trought ESP8266 it does not work. The status code response is always -1.

I opened a Ngrok tunnel to my web server to find out what is going on and found that the ESP8266 request didn't even touch the application.

Here is my code:

main.cpp file

#include "http_requests.h"

const char* wifi_ssid = "ssid";
const char* wifi_password = "password";

void setup()
{
    Serial.begin(115200);
    delay(1000);

    WiFi.begin(wifi_ssid, wifi_password);
    delay(1000);
}

void loop()
{
    do_post();
    delay(3000);
}

http_requests.h file:

#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
#include <json_utils.h>

String serverPath = "http://192.168.49.2:30055";

void do_post()
{
    if (WiFi.status() == WL_CONNECTED)
    {
        std::unique_ptr<BearSSL::WiFiClientSecure> client(new BearSSL::WiFiClientSecure);

        client->setInsecure();

        HTTPClient http;

        // String path = serverPath + "/messages";
        String body = generate_message_json(WiFi.macAddress(), "TEST TESTE");
        // The method above is working fine, it generate the json as I need.

        http.begin(*client, "http://192.168.49.2:30055/messages");
        http.addHeader("Content-Type", "application/json; charset=UTF-8");

        Serial.println("body: ");
        Serial.print(body);

        int httpCode = http.POST(body);

        Serial.println("HTTP STATUS RESPONSE: ");
        Serial.println(httpCode); // always prints -1

        http.end();
    }
}

As I said, the function that creates JSON is working fine.

There is no error on the terminal.

What can I do to solve it?

[Juraj]

you use secure client for a http request. it will not work.
simply use WiFiClient, not WiFiClientSecure

[vitornilson1998]

@Juraj same error using WiFiClient. Still having -1 as response.

[Juraj]

is port 30055 open on firewall on 192.168.49.2?

[vitornilson1998]

@Juraj Yes, I can do a telnet to this IP and get connected.

I think the main problem is that HTTPClient does not even do a request. As I said, I opened a HTTP tunnel with Ngrok and nothing prints on Ngrok console.

[Juraj]

I would like to see the version of your code with WiFiClient

[vitornilson1998]

Ok, the main.cpp does not change in nothing.

Here is the http_requests.h:

#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>
#include <json_utils.h>

String serverPath = "http://192.168.49.2:30055";

void do_post()
{
    if (WiFi.status() == WL_CONNECTED)
    {
        WiFiClient client;

        HTTPClient http;

        String path = serverPath + "/messages";
        String body = generate_message_json(WiFi.macAddress(), "TEST TESTE");


        http.begin(client, "http://192.168.49.2:30055/messages");
        http.addHeader("Content-Type", "application/json; charset=UTF-8");

        Serial.println("body: ");
        Serial.print(body);

        int httpCode = http.POST(body);

        Serial.println("HTTP STATUS RESPONSE: ");
        Serial.println(httpCode);

        http.end();
    }
}

I would like to add some information, I did some packet sniffing with wireshark on my local K8S cluster and really, no requests made by ESP8266 arrives.