POST request fails while using libcurl, C++ - c++

Question

TEST(ApiTest, TestPostMethod) {
CURL *curl;
CURLcode res;
curl_global_init(CURL_GLOBAL_ALL);
curl = curl_easy_init();
if (curl) {
curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
std::string url = "https://postman-echo.com/post";
curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
curl_easy_setopt(curl, CURLOPT_DEFAULT_PROTOCOL, "https");
struct curl_slist *headers = NULL;
// curl_slist_append(headers, "HOST: postman-echo.com");
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
ASSERT_EQ(CURLE_OK, res);
}
}
Error: CURLE_COULDNT_RESOLVE_HOST (6)
When I tested this POST request on postman it worked as expected. Also curl command
curl --location --request POST 'https://postman-echo.com/post'
works fine.
Expected equality of these values:
CURLE_OK
Which is: 0
res
Which is: 6
Run NSLOOKUP as suggested by #Andreas Wenzel
> postman-echo.com
Server: 75.75.75.75
Address: 75.75.75.75#53
Non-authoritative answer:
Name: postman-echo.com
Address: 3.210.84.203
Name: postman-echo.com
Address: 52.22.211.29

Answer 1

https://github.com/alexzk1/ed_highway/blob/master/utils/restclient.cpp
this works for many sites last 3-4 years. you can pick those 2 files only.
It uses CURLOPT_POSTFIELDS for post.
Btw, in your code u're following redirects, are u sure website don't redirect you to non-existing link?

Answer 2

Sorry. I figured this out. My server on which I was run this has restrictions in connecting with outside world. Thanks everyone for looking into this.