Remote accessing mysql server running on docker container

Question

How to access the MySQL server running on a Docker container in a remote machine.

Here is my dockerfile:

MAINTAINER debu_bbsr@yahoo.com
RUN apt-get update \
 && DEBIAN_FRONTEND=noninteractive apt-get install -y mysql-server \
 && sed -i "s/127.0.0.1/0.0.0.0/g" /etc/mysql/mysql.conf.d/mysqld.cnf \
 && mkdir /var/run/mysqld \
 && chown -R mysql:mysql /var/run/mysqld

VOLUME ["/var/lib/mysql"]

EXPOSE 3306

CMD ["mysqld_safe"]

I created an image:

sudo docker build -t deb_mysql_image .

Run the Docker container with the above image:

sudo docker run -i -t -d -p 3306:3306 --name mysql_deb_container deb_mysql_image

Enter into the MySQL container:

`k8smaster@k8smaster:~/debashish$ sudo docker exec -it mysql_deb_container mysql`

Create different users and database:

mysql> create user debashish identified by 'debashish';
mysql> create user debmysql identified by 'debmysql';
mysql> create database debdb;
mysql> use debdb;

Grant privileges to the users and create a table:

mysql> GRANT ALL PRIVILEGES ON *.* TO 'debashish' WITH GRANT OPTION;  



CREATE TABLE debtbl1 (name VARCHAR(20), address VARCHAR(50));

Populate the table:

insert into debtbl1 values('Debashish', 'Shanghai');
insert into debtbl1 values('Debu', 'Livingston, Shanghai');

Now access the contents of the above MySQL table from a remote machine with the MySQL client:

k8snode1@k8snode1:~$ mysql -u 'debashish' -p  -h 10.10.10.2 -P 3306 -D debdb
Enter password

"Sometimes" I encounter the issue -

ERROR 1045 (28000): Access denied for user

Anything am I missing to make it a robust system so I dont encounter "sometimes" the above error.

Answer 1

Most likely your user doesn't have permissions to access from that server, either grant privileges for that specific server or globally.

Run:

GRANT ALL PRIVILEGES ON *.* TO 'debashish'@'%' WITH GRANT OPTION; 
FLUSH PRIVILEGES;

Answer 2

The issue was that - whenever a Pod was restarted, all the privileges assigned to the Mysql DB also gets erased.

Hence the solution was to - write a shell script that will be:

    1.  Executed when the Pod is started/scaled-in/container is started.
    2.  The shell script automatically creates the database and users.
    3.  Shell script then grants permission to the users for the DB.