MySQLi real_connect Failed

I'm unable to connect MySQL database(that exists in another server) with SSL in below PHP code. I tried the steps from the link: https://learn.microsoft.com/en-us/azure/mysql/howto-configure-ssl

Can anyone advise me what should be done from those steps?

FYI, I can connect the MySQL database from the command line.

Failed to connect to MySQL: php_network_getaddresses: getaddrinfo failed: Name or service not known

    $db = mysqli_init();
    //mysqli_options ($db, MYSQLI_OPT_SSL_VERIFY_SERVER_CERT, true);
    mysqli_ssl_set($db,"/var/www/html/path/cert/client-key.pem","/var/www/html/path/cert/client-cert.pem","/var/www/html/path/BaltimoreCyberTrustRoot.crt.pem",NULL,NULL);
    $c=mysqli_real_connect($db, 'example.com','uname@uname','mypassword','database',3306,NULL, MYSQLI_CLIENT_SSL);
    if(mysqli_connect_errno($db)){
     echo "<br>Failed to connect to MySQL: " . mysqli_connect_error();
    }
    else
    {
    $sql = 'show tables ';
    echo $sql.'<br>';
    $result = mysqli_query($db,$sql); 
    $rows = array();
    if(!empty($result)){
                while ($row = mysqli_fetch_assoc($result)){
                $rows[] = $row;
                echo '<pre>'; echo json_encode($row, JSON_PRETTY_PRINT);
                }
          }
    }

Are you trying this in Azure? Please make sure the pem file has correct path and permission

Things to fix while connecting the database:

1. Download this pem key and rename the file "BaltimoreCyberTrustRoot.crt.pem" https://www.digicert.com/CACerts/BaltimoreCyberTrustRoot.crt.pem

2. Enable SSL connection in azure server.

3. Directly run the MySQL command "status" in the database and check SSL: Cipher in use is AES256-SHA
4. Add the below code in a test file and make sure hostname, username, password, port and pem file's path & permission, are very correct.

Try the following code sample :

    {
$db = mysqli_init();  mysqli_ssl_set($db,NULL,NULL,"/var/www/html/path/BaltimoreCyberTrustRoot.crt.pem",NULL,NULL);
$connection = mysqli_real_connect($db, 'example.com','uname@uname','mypassword','database_name',3306,NULL, MYSQLI_CLIENT_SSL);


   if(mysqli_connect_errno($db))
   { 
echo "<br><b>Failed to connect to MySQL: " . mysqli_connect_error()."<b>";
   } 
else
   {
   $sql = 'show tables ';
   $result = mysqli_query($db,$sql);
   $rows = array();
   if(!empty($result))
        {
             while ($row = mysqli_fetch_assoc($result)){
             $rows[] = $row;
             echo '<pre>'; print_R($row);
         }
     }
    }