php slack 비공개 채널에 post message curl

1. 비공개 채널에, 글을 게시할 Bot 을 추가 한다.

<?php

$channel_id = "<channel_id>";
$token = "<token>";
$message = "Hello World";

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "https://slack.com/api/chat.postMessage?token=$token&channel=$channel_id&text=$message",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => array(
    "Content-Type: application/x-www-form-urlencoded"
  ),
));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

?>