CentOS 7 Cannot find autoconf

When install redis php module, i get error

Cannot find autoconf. Please check your autoconf installation and the
$PHP_AUTOCONF environment variable. Then, rerun this script.

[root@vps154294 phpredis]# /usr/serverok/php-7.1.12/bin/phpize
Configuring for:
PHP Api Version:         20160303
Zend Module Api No:      20160303
Zend Extension Api No:   320160303
Cannot find autoconf. Please check your autoconf installation and the
$PHP_AUTOCONF environment variable. Then, rerun this script.

[root@vps154294 phpredis]#

This is fixed by installing autoconf package with yum.

yum install -y autoconf

Once autoconf installed, phpize command worked properly.

[root@vps154294 phpredis]# /usr/serverok/php-7.1.12/bin/phpize
Configuring for:
PHP Api Version:         20160303
Zend Module Api No:      20160303
Zend Extension Api No:   320160303
[root@vps154294 phpredis]#