# Securing and Efficiently Managing MySQL Server Deployment in Docker: Best Practices for Database Backup and Restoration For this first, we have to set up docker on a Linux machine (Ex- AWS Instance, On-Primise, Virtual Machine, etc). ### Step-1 (Setup Docker on Virtual Machine.) I have Rhel 9 OS with 4 GB RAM and a 2Vc Core CPU. Follow this official Docker community to set up Docker Engine in Centos: [https://docs.docker.com/engine/install/centos/](https://docs.docker.com/engine/install/centos/) ### Step-2 (Deploy MySQL container on docker.) ```plaintext # docker info # docker --version # docker images ``` Pull MySQL Image and create a volume directory for attaching with MySQL container configuration directory. Don't forget to make a mysql port 3606 entry in the firewall. ```plaintext # mkdir -p /vol/mysql_data # firewall-cmd --list-all # firewall-cmd --permanent --add-port=3606/tcp # firewall-cmd --reload ``` ```plaintext # docker pull mysql:latest # docker images REPOSITORY TAG IMAGE ID CREATED SIZE mysql latest a3b6608898d6 3 weeks ago 596MB # mkdir -p /vol/mysql_data ``` Run MySQL container ```plaintext # docker run -d --name=mysql_con -v /vol/mysql_data:/var/lib/mysql --restart=on-failure -e MYSQL_ROOT_PASSWORD="password" -p 3606:3606 mysql:latest # docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 31ea49f88d41 mysql:latest "docker-entrypoint.s…" 6 seconds ago Up 5 seconds 3306/tcp, 33060/tcp, 0.0.0.0:3606->3606/tcp, :::3606->3606/tcp mysql_con ``` Enter in MySQL Container ```plaintext # docker exec -it 31ea49f88d41 bash # mysql -u root -p ``` ### Step-2.1 (Deploy MySQL/MariaDB on Base Machine ) ```plaintext # yum install mariadb-server mariadb -y # systemctl start mariadb.service && systemctl enable mariadb.service # mysql_secure_installation # mysql -u root -p ``` --- ### Step-3 (Create a Database.) Now we are going to create a new MySQL database inside MySQL container and show database. ```sql bash-4.4# mysql --version mysql Ver 8.2.0 for Linux on x86_64 (MySQL Community Server - GPL) bash-4.4# mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 8 Server version: 8.2.0 MySQL Community Server - GPL Copyright (c) 2000, 2023, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. ``` Show how many databases have already been created in MySQL. ```sql mysql> show databases ; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.01 sec) ``` Here only four databases are present. So first we create our database named "wordpress". ```sql mysql> CREATE DATABASE wordpress; Query OK, 1 row affected (0.00 sec) ``` Now we will use this newly created database, so enter it into "WORDPRESS" database. After this, we will create a table "authors" and insert some table data. ```sql mysql> USE wordpress; Database changed mysql> CREATE TABLE authors (id INT, name VARCHAR(20), email VARCHAR(20)); Query OK, 0 rows affected (0.02 sec) mysql> INSERT INTO authors (id,name,email) VALUES(1,"Vivek","xuz@abc.com"); Query OK, 1 row affected (0.03 sec) mysql> INSERT INTO authors (id,name,email) VALUES(2,"Priya","p@gmail.com"); Query OK, 1 row affected (0.00 sec) mysql> INSERT INTO authors (id,name,email) VALUES(3,"Tom","tom@yahoo.com"); Query OK, 1 row affected (0.00 sec) mysql> INSERT INTO authors (id,name,email) VALUES(4,"Jerry","jerry@yahoo.com"); Query OK, 1 row affected (0.00 sec) ``` We can see we have created a new table in "wordpress" database. We can describe this table using the below MySQL query. ```sql mysql> SHOW TABLES; +---------------------+ | Tables_in_wordpress | +---------------------+ | authors | +---------------------+ 1 row in set (0.01 sec) mysql> DESCRIBE authors; +-------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+-------------+------+-----+---------+-------+ | id | int | YES | | NULL | | | name | varchar(20) | YES | | NULL | | | email | varchar(20) | YES | | NULL | | +-------+-------------+------+-----+---------+-------+ 3 rows in set (0.00 sec) ``` As we can see inserted table data, there are four records in this table. ```sql mysql> SELECT * FROM authors; +------+-------+-----------------+ | id | name | email | +------+-------+-----------------+ | 1 | Vivek | xuz@abc.com | | 2 | Priya | p@gmail.com | | 3 | Tom | tom@yahoo.com | | 4 | Jerry | jerry@yahoo.com | +------+-------+-----------------+ 4 rows in set (0.00 sec) ``` ### Step-3.1 (User Create and grant permission to access database) Creating a new user "rakesh" and assigned password to access the database from localhost `'rakesh'@'localhost'`. ```sql mysql> CREATE USER 'rakesh'@'localhost' IDENTIFIED BY 'password'; Query OK, 0 rows affected (0.02 sec) ```
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Note 3.1.1: If you want to access the database from anywhere by user "rakesh".
```sql mysql> CREATE USER 'rakesh'@'%' IDENTIFIED BY 'password'; Query OK, 0 rows affected (0.02 sec) ```
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Note 3.1.2: In Case to drop a created user.
```sql mysql> DROP USER 'rakesh'@'%'; Query OK, 0 rows affected (0.05 sec) mysql> DROP USER 'rakesh'@'localhost'; Query OK, 0 rows affected (0.05 sec) ```
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Note 3.1.3: Grant access authorization on specific database and there all tables at once. and access through the localhost server (Where the actual mysql server is running).
```sql mysql> GRANT ALL PRIVILEGES ON WORDPRESS.* TO 'rakesh'@'localhost' WITH GRANT OPTION; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> FLUSH PRIVILEGES; ```
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Note 3.1.4: If you want to give authorization access to all databases and their tables *.* at once, and access from anywhere using user rakesh 'rakesh'@'%'. You can try this.
```sql mysql> GRANT ALL PRIVILEGES ON *.* TO 'rakesh'@'%' WITH GRANT OPTION; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> FLUSH PRIVILEGES; ``` If you want to check, which database is assigned to which user .
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Note 3.1.5: There is a special pre-configured database named "mysql" inside MySQL. That has overall databases user credentials and much more information. Here You can check "rakesh" user is authorized to access the "WORDPRESS" database.
```sql mysql> show databases; mysql> use mysql; mysql> show tables; mysql> select Host, User from user; +-----------+------------------+ | Host | User | +-----------+------------------+ | % | root | | localhost | mysql.infoschema | | localhost | mysql.session | | localhost | mysql.sys | | localhost | root | | localhost | rakesh | +-----------+------------------+ 6 rows in set (0.00 sec) ```
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Note 3.1.6: Login with new user rakesh and check whether this is authenticated and authorized to access the database from localhost.
```sql bash-4.4# mysql -u rakesh -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 12 Server version: 8.2.0 MySQL Community Server - GPL Copyright (c) 2000, 2023, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | performance_schema | | wordpress | +--------------------+ 3 rows in set (0.00 sec) mysql> use wordpress; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> show tables; +---------------------+ | Tables_in_wordpress | +---------------------+ | authors | +---------------------+ 1 row in set (0.00 sec) mysql> select * from authors; +------+-------+-----------------+ | id | name | email | +------+-------+-----------------+ | 1 | Vivek | xuz@abc.com | | 2 | Priya | p@gmail.com | | 3 | Tom | tom@yahoo.com | | 4 | Jerry | jerry@yahoo.com | +------+-------+-----------------+ 4 rows in set (0.00 sec) ```
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Note 3.1.7: If you faced such error to access using user rakesh "ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)"
```plaintext bash-4.4# mysql -u root -p Enter password: ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) bash-4.4# --------- Make entry of container_ip with localhost in hosts file bash-4.4# cat /etc/hosts bash-4.4# echo " localhost" >> /etc/hosts --------- Now try with same login bash-4.4# mysql -u rakesh -p Enter password: ``` --- ### Step-4 (Create a backup of MySQL database.)
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Note 4.1: Make sure you are not inside of any database, and you are on a container shell, and you give enough privileges to your user to take backup. check notes point: Note: 3.1.4
```plaintext bash-4.4# mysqldump -u rakesh -p wordpress > /var/lib/mysql/mysql_backup.sql Enter password: bash-4.4# ls -l /var/lib/mysql total 100712 -rw-r-----. 1 mysql mysql 196608 Nov 22 04:33 '#ib_16384_0.dblwr' -rw-r-----. 1 mysql mysql 8585216 Nov 21 12:31 '#ib_16384_1.dblwr' drwxr-x---. 2 mysql mysql 4096 Nov 22 03:51 '#innodb_redo' drwxr-x---. 2 mysql mysql 187 Nov 22 03:51 '#innodb_temp' -rw-r-----. 1 mysql mysql 56 Nov 21 12:31 auto.cnf -rw-r-----. 1 mysql mysql 3039831 Nov 21 12:31 binlog.000001 -rw-r-----. 1 mysql mysql 2977 Nov 21 13:43 binlog.000002 -rw-r-----. 1 mysql mysql 2860 Nov 22 04:33 binlog.000003 -rw-r-----. 1 mysql mysql 48 Nov 22 03:51 binlog.index -rw-------. 1 mysql mysql 1680 Nov 21 12:31 ca-key.pem -rw-r--r--. 1 mysql mysql 1108 Nov 21 12:31 ca.pem -rw-r--r--. 1 mysql mysql 1108 Nov 21 12:31 client-cert.pem -rw-------. 1 mysql mysql 1676 Nov 21 12:31 client-key.pem -rw-r-----. 1 mysql mysql 4317 Nov 21 13:43 ib_buffer_pool -rw-r-----. 1 mysql mysql 12582912 Nov 22 04:33 ibdata1 -rw-r-----. 1 mysql mysql 12582912 Nov 22 03:51 ibtmp1 drwxr-x---. 2 mysql mysql 143 Nov 21 12:31 mysql -rw-r-----. 1 mysql mysql 32505856 Nov 22 04:33 mysql.ibd lrwxrwxrwx. 1 mysql mysql 27 Nov 22 03:51 mysql.sock -> /var/run/mysqld/mysqld.sock -rw-r--r--. 1 root root 2007 Nov 22 04:54 mysql_backup.sql drwxr-x---. 2 mysql mysql 8192 Nov 21 12:31 performance_schema -rw-------. 1 mysql mysql 1680 Nov 21 12:31 private_key.pem -rw-r--r--. 1 mysql mysql 452 Nov 21 12:31 public_key.pem -rw-r--r--. 1 mysql mysql 1108 Nov 21 12:31 server-cert.pem -rw-------. 1 mysql mysql 1676 Nov 21 12:31 server-key.pem drwxr-x---. 2 mysql mysql 28 Nov 21 12:31 sys -rw-r-----. 1 mysql mysql 16777216 Nov 22 04:33 undo_001 -rw-r-----. 1 mysql mysql 16777216 Nov 22 04:32 undo_002 drwxr-x---. 2 mysql mysql 25 Nov 22 04:30 wordpress bash-4.4# cat /var/lib/mysql/mysql_backup.sql ``` ### Step-4.1 (Create recursive backup automatically and send it onto a different server using rsync.) The backup of the WordPress database was created from a Docker container named `mysql_con`, using the user named `rakesh`. This backup was stored at the location `/var/lib/mysql`. This location is where MySQL stores various types of configuration files and important data. Additionally, this specific location (`/var/lib/mysql`) is connected to a directory in the BaseOS system named `/vol/mysql_data`. This connection was established when we attached it using the `-v` option in Docker. So we will create a cronjob with user rakesh on BaseOS, where docker is running. (or you can create a cronjob inside the docker container as well)
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Note 4.1.1: If you are working on a docker mysql container, try this.
If you are working on a docker container. Create a .my.cnf file inside your docker mysql\_con container with the following configuration `(Then you don't need to reveal your username and password each time).` ```plaintext bash-4.4# vi ~/.my.cnf [client] user=username password=yourpass :wq! ``` Then come to BaseOS, and create a script file. ```plaintext [root@localhost ~]# vi /root/script.sh #!/bin/bash mysqldump wordpress > /var/lib/mysql/mysql_backup.sql :wq! ```
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Then create a crontab file to schedule cronjob to take backup every 15 minutes.
```plaintext [root@localhost ~]# crontab -e -u root */15 * * * * docker exec mysql_con /bin/bash /root/script.sh */16 * * * * rsync -avz /var/lib/mysql/mysql_backup.sql /root/mysql_backup ``` Don't forgot to restart crond service for crontab jobs. ```plaintext oot@localhost ~]# systemctl restart crond ```
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Note: You can check updated backup and there timestamp
```plaintext [root@localhost mysql_data]# ls -al /root/mysql_backup total 8 drwxr-xr-x. 2 root root 30 Nov 22 11:53 . dr-xr-x---. 15 root root 4096 Nov 22 11:55 .. -rw-r--r--. 1 root root 1273 Nov 22 11:13 mysql_backup.sql ```
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Note: If you want to send a backup from the MySQL Host Server to another server, you can set "rsync" between two different servers.
--- ### Step-5 (Restore backup of MySQL database.)
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Make sure you are on container bash, not inside the MySQL database.
```plaintext bash-4.4# mysql wordpress < /var/lib/mysql/mysql_backup.sql ``` --- --- ### Some MySQL Interview Questions :
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Here we will discuss some most important MySQL-related questions.
`Question-1` How to reset MySQL root password? > `Step-1:` Suppose your MySQL database server is running on local machine. So first stop the MySQL server service. > > ```plaintext > [root@localhost ~]# systemctl status mysql > [root@localhost ~]# systemctl stop mysql > ``` > > `Step-2:` Find mysqld process id and kill it using `kill -9 pid_mysqld` or `kill -19 pid_mysqld.` > > ```sql > [root@localhost ~]# top > [root@localhost ~]# kill -9 25691 > [root@localhost ~]# kill -19 25691 > > ----------- Check using top command, whether it is mysqld process is still running or not > [root@localhost ~]# top > ``` > > `Step-3:` Run mysql in safe mode --- `Question-2` What is the main difference between DROP, DELETE & TRUNCATE commands in MySQL Query? > Suppose You have a database "earth" and there is some table inside it like "continents, oceans, animals, humans, birds". Now you want to remove some records from the database, tables, records & databases etc. These things can be implemented by DROP, DELETE, and TRUNCATE Query commands. > > * DROP = Data + Structure of Table will be removed. (Ex: complete Table, Database). > > ```sql > DROP table ; > DROP database ; > ``` > > * DELETE = Only the data part will be removed and no sequence will be changed for the next record. (No counter will be reset. (Ex- 1,2,3,4,5 ) and then (6,7,8,9,10 ...) > > ```sql > DELETE FROM table_name WHERE condition; > ``` > > * TRUNCATE = All rows/records will be deleted (remove) and sequence (Counter) will be reset. (Ex- 1,2,3,4,5 ) and then (1,2,3,4,5,6,7 ...) > > ```sql > TRUNCATE table ; > ``` > --- `Question-3` How to assign "CREATE, ALTER, DROP, INSERT, UPDATE, DELETE and SELECT " grant permissions to a user Rakesh on wordpress database, which can access the database from localhost and anywhere? > `Note-3.1:` First, if you don't have any users, you create the user and then grant the permissions. To `GRANT ALL` privileges to a `user`, allowing that user full control over a specific `database`, use the following syntax: > > ```sql > mysql> CREATE USER 'Rakesh'@'%' IDENTIFIED BY 'password'; > Query OK, 0 rows affected (0.02 sec) > > ------------------------------------------------------------ > mysql> GRANT ALL PRIVILEGES ON wordpress.* TO 'Rakesh'@'%'; > Query OK, 0 rows affected (0.02 sec) > > mysql> GRANT ALL PRIVILEGES ON wordpress.table_name TO 'Rakesh'@'localhost'; > Query OK, 0 rows affected (0.02 sec) > ``` > > `Note-3.2:` Specific Grant permissions to user Rakesh on database wordpress to access from localhost and anywhere. > > ```sql > mysql> GRANT CREATE, ALTER, DROP, INSERT, UPDATE, DELETE, SELECT, REFERENCES, RELOAD on wordpress.* TO 'Rakesh'@'%' WITH GRANT OPTION; > Query OK, 0 rows affected (0.02 sec) > > > mysql> GRANT CREATE, ALTER, DROP, INSERT, UPDATE, DELETE, SELECT, REFERENCES, RELOAD on wordpress.table_name TO 'Rakesh'@'localhost' WITH GRANT OPTION; > Query OK, 0 rows affected (0.02 sec) > ``` --- `Question-4` We have two users Rakesh & Anjali, and Two databases College & School as well. Now how will you Assign the College database to access user Anjali with specific IP 192.175.23.10, and the School database with user Rakesh with access from anywhere? > ```sql > mysql> GRANT ALL PRIVILEGES ON > -> College.* TO 'Anjali'@'192.175.23.10' > -> WITH GRANT OPTION; > Query OK, 0 rows affected (0.00 sec) > > --------------------------------------------------------------------------- > mysql> GRANT ALL PRIVILEGES ON > -> School.* TO 'Rakesh'@'%' > -> WITH GRANT OPTION; > Query OK, 0 rows affected (0.01 sec) > > --------------------------------------------------------------------------- > mysql> USE mysql; > Database changed > mysql> SELECT User, Host > -> FROM user; > > +------------------+------------+ > | User | Host | > +------------------+------------+ > | Anjali | 172.17.0.2 | > | Rakesh | % | > | root | % | > | mysql.infoschema | localhost | > | mysql.session | localhost | > | mysql.sys | localhost | > | root | localhost | > +------------------+------------+ > 7 rows in set (0.00 sec) > --------------------------------------------------------------------------- > bash-4.4# mysql -u Rakesh -p > Enter password: > mysql> show databases; > +--------------------+ > | Database | > +--------------------+ > | School | > | information_schema | > | performance_schema | > +--------------------+ > 3 rows in set (0.01 sec) > --------------------------------------------------------------------------- > bash-4.4# mysql -u Anjali -p -h 172.17.0.2 > Enter password: > mysql> show databases; > +--------------------+ > | Database | > +--------------------+ > | College | > | information_schema | > | performance_schema | > +--------------------+ > 3 rows in set (0.01 sec) > ``` --- `Question-5` How we can know user (Ex:- Rakesh) access on a specific host? > There is a pre-existing 'mysql' database within the MySQL server, specifically designed to store all the system's internal configurations, user accounts, privileges, and other crucial system-related information. > > ```sql > bash-4.4# mysql -u root -p > Enter password: > > ---------------------------------------------------------------------- > mysql> SHOW DATABASES; > +--------------------+ > | Database | > +--------------------+ > | information_schema | > | mysql | > | performance_schema | > | sys | > | wordpress | > +--------------------+ > 5 rows in set (0.02 sec) > > ---------------------------------------------------------------------- > mysql> USE mysql; > Reading table information for completion of table and column names > You can turn off this feature to get a quicker startup with -A > Database changed > > ---------------------------------------------------------------------- > mysql> mysql> show tables; > +------------------------------------------------------+ > | Tables_in_mysql | > +------------------------------------------------------+ > | columns_priv | > | component | > | db | > | default_roles | > | engine_cost | > | func | > | general_log | > | global_grants | > | gtid_executed | > | help_category | > | help_keyword | > | help_relation | > | help_topic | > | innodb_index_stats | > | innodb_table_stats | > | ndb_binlog_index | > | password_history | > | plugin | > | procs_priv | > | proxies_priv | > | replication_asynchronous_connection_failover | > | replication_asynchronous_connection_failover_managed | > | replication_group_configuration_version | > | replication_group_member_actions | > | role_edges | > | server_cost | > | servers | > | slave_master_info | > | slave_relay_log_info | > | slave_worker_info | > | slow_log | > | tables_priv | > | time_zone | > | time_zone_leap_second | > | time_zone_name | > | time_zone_transition | > | time_zone_transition_type | > | user | > +------------------------------------------------------+ > 38 rows in set (0.00 sec) > > ---------------------------------------------------------------------- > mysql> SELECT User, Host from user; > +------------------+-----------+ > | User | Host | > +------------------+-----------+ > | root | % | > | mysql.infoschema | localhost | > | mysql.session | localhost | > | mysql.sys | localhost | > | rakesh | localhost | > | root | localhost | > +------------------+-----------+ > 6 rows in set (0.00 sec) > > mysql> > ``` `Question-6` How to remove a user from the MySQL database? > To remove a user from the database, you have to be login from root login. > > ```sql > bash-4.4# mysql -u root -p > Enter password: > ---------------------------------------------------------------------- > mysql> select User, Host from user; > +------------------+------------+ > | User | Host | > +------------------+------------+ > | Anjali | % | > | Rakesh | % | > | root | % | > | Sita | 172.17.0.2 | > | mysql.infoschema | localhost | > | mysql.session | localhost | > | mysql.sys | localhost | > | root | localhost | > +------------------+------------+ > 8 rows in set (0.00 sec) > ---------------------------------------------------------------------- > mysql> DROP USER 'Rakesh'@'%'; > Query OK, 0 rows affected (0.01 sec) > ``` --- `Question-7` What is the use of "FLUSH PRIVILEGES" command in MySQL database? > Executing `FLUSH PRIVILEGES` tells the MySQL server to discard the current in-memory privileges and reload the grant tables, ensuring that any recent modifications to user privileges or access rights take effect immediately without requiring a server restart. > > It's important to note that in modern versions of MySQL, many privilege-related changes automatically take effect without explicitly running `FLUSH PRIVILEGES`. However, there are specific scenarios where executing this command might be necessary to ensure immediate application of privilege changes, especially after directly modifying the grant tables. --- `Question-8` Give Anjali user grant permission to access only the oceans table in the earth database. > ```sql > mysql> GRANT ALL PRIVILEGES ON > -> earth.oceans TO 'Anjali'@'%' > -> WITH GRANT OPTION; > Query OK, 0 rows affected (0.01 sec) > ``` `Question-9` What is the format to write date datatype in MySQL & Oracle? > In Oracle : DD-MM-YYYY > > In MySQL: YYYY-MM-DD --- ### References: * `Docker setup on centos:` [https://docs.docker.com/engine/install/centos/](https://docs.docker.com/engine/install/centos/) * `Create database, and tables and insert the data:` [https://www.w3schools.com/sql/sql\_create\_table.asp](https://www.w3schools.com/sql/sql_create_table.asp) * `Create user and grant permissions:` [https://www.digitalocean.com/community/tutorials/how-to-create-a-new-user-and-grant-permissions-in-mysql](https://www.digitalocean.com/community/tutorials/how-to-create-a-new-user-and-grant-permissions-in-mysql) * `How to Use the Rsync Utility to Make a Remote Backup of a Linux System:` [https://jumpcloud.com/blog/how-to-use-rsync-remote-backup-linux-system#:~:text=By%20default%2C%20rsync%20does%20not,times%20using%20a%20cron%20job](https://jumpcloud.com/blog/how-to-use-rsync-remote-backup-linux-system#:~:text=By%20default%2C%20rsync%20does%20not,times%20using%20a%20cron%20job). * `Hide your credentials publically during the crontab task:` [https://stackoverflow.com/questions/62287061/connect-to-2-instances-of-mysql-with-no-password-interaction-using-command-line#:~:text=Do%20chmod%20600%20~%2F.,like%20user%20can%20see%20it.&text=That%20allows%20you%20to%20just%20type%20mysql%20and%20log%20on](https://stackoverflow.com/questions/62287061/connect-to-2-instances-of-mysql-with-no-password-interaction-using-command-line#:~:text=Do%20chmod%20600%20~%2F.,like%20user%20can%20see%20it.&text=That%20allows%20you%20to%20just%20type%20mysql%20and%20log%20on).