I cannot build the image !!

[al-ani]

when I try to build the Dockerfile I get these errors:

update-alternatives: using /etc/mysql/mysql.cnf to provide /etc/mysql/my.cnf (my.cnf) in auto mode
invoke-rc.d: policy-rc.d denied execution of start.
Processing triggers for ureadahead (0.100.0-16) ...
Setting up mysql-server (5.7.15-1ubuntu14.04) ...
Processing triggers for libc-bin (2.19-0ubuntu6.9) ...
---> f1be1f9aed7e
Removing intermediate container eda4f8a6ae28
Step 24 : RUN /usr/sbin/mysqld & sleep 10s && echo "GRANT ALL ON . TO root@'0.0.0.0' IDENTIFIED BY 'secret' WITH GRANT OPTION; CREATE USER 'homestead'@'0.0.0.0' IDENTIFIED BY 'secret'; GRANT ALL ON . TO 'homestead'@'0.0.0.0' IDENTIFIED BY 'secret' WITH GRANT OPTION; GRANT ALL ON . TO 'homestead'@'%' IDENTIFIED BY 'secret' WITH GRANT OPTION; FLUSH PRIVILEGES; CREATE DATABASE homestead;" | mysql
---> Running in ce1d1b1460fa
mysqld: [ERROR] Found option without preceding group in config file /etc/mysql/my.cnf at line 18!
mysqld: [ERROR] Fatal error in defaults handling. Program aborted!
mysql: [ERROR] Found option without preceding group in config file /etc/mysql/my.cnf at line 18!
mysql: [ERROR] Fatal error in defaults handling. Program aborted!
The command '/bin/sh -c /usr/sbin/mysqld & sleep 10s && echo "GRANT ALL ON . TO root@'0.0.0.0' IDENTIFIED BY 'secret' WITH GRANT OPTION; CREATE USER 'homestead'@'0.0.0.0' IDENTIFIED BY 'secret'; GRANT ALL ON . TO 'homestead'@'0.0.0.0' IDENTIFIED BY 'secret' WITH GRANT OPTION; GRANT ALL ON . TO 'homestead'@'%' IDENTIFIED BY 'secret' WITH GRANT OPTION; FLUSH PRIVILEGES; CREATE DATABASE homestead;" | mysql' returned a non-zero code: 1

Please, can you figure out what is the problem?