How to perform a mysqldump without a password prompt?

Question

I would like to know the command to perform a mysqldump of a database without the prompt for the password.

REASON: I would like to run a cron job, which takes a mysqldump of the database once everyday. Therefore, I won't be able to insert the password when prompted.

How could I solve this ?

Answer 1

Since you are using Ubuntu, all you need to do is just to add a file in your home directory and it will disable the mysqldump password prompting. This is done by creating the file ~/.my.cnf (permissions need to be 600).

Add this to the .my.cnf file

[mysqldump]
user=mysqluser
password=secret

This lets you connect as a MySQL user who requires a password without having to actually enter the password. You don't even need the -p or --password.

Very handy for scripting mysql & mysqldump commands.

The steps to achieve this can be found in this link.

Alternatively, you could use the following command:

mysqldump -u [user name] -p[password] [database name] > [dump file]

but be aware that it is inherently insecure, as the entire command (including password) can be viewed by any other user on the system while the dump is running, with a simple ps ax command.

Answer 2

Adding to @Frankline's answer:

The -p option must be excluded from the command in order to use the password in the config file.

Correct:
mysqldump –u my_username my_db > my_db.sql

Wrong:
mysqldump –u my_username -p my_db > my_db.sql

---

.my.cnf can omit the username.

[mysqldump]
password=my_password

---

If your .my.cnf file is not in a default location and mysqldump doesn't see it, specify it using --defaults-file.

mysqldump --defaults-file=/path-to-file/.my.cnf –u my_username my_db > my_db.sql

Answer 3

A few answers mention putting the password in a configuration file.

Alternatively, from your script you can export MYSQL_PWD=yourverysecretpassword.

The upside of this method over using a configuration file is that you do not need a separate configuration file to keep in sync with your script. You only have the script to maintain.

There is no downside to this method.

The password is not visible to other users on the system (it would be visible if it is on the command line). The environment variables are only visible to the user running the mysql command, and root.

The password will also be visible to anyone who can read the script itself, so make sure the script itself is protected. This is in no way different than protecting a configuration file. You can still source the password from a separate file if you want to have the script publicly readable (export MYSQL_PWD=$(cat /root/mysql_password) for example). It is still easier to export a variable than to build a configuration file.

E.g.,

$ export MYSQL_PWD=$(>&2 read -s -p "Input password (will not echo): "; echo "$REPLY")
$ mysqldump -u root mysql | head
-- MySQL dump 10.13  Distrib 5.6.23, for Linux (x86_64)
--
-- Host: localhost    Database: mysql
-- ------------------------------------------------------
-- Server version   5.6.23
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;

MariaDB

MariaDB documents the use of MYSQL_PWD as:

Default password when connecting to mysqld. It is strongly recommended to use a more secure method of sending the password to the server.

The page has no mentions of what a "more secure" method may be.

MySQL

This method is still supported in the latest documented version of MySQL: https://dev.mysql.com/doc/refman/8.0/en/environment-variables.html though it comes with the following warning:

Use of MYSQL_PWD to specify a MySQL password must be considered extremely insecure and should not be used. Some versions of ps include an option to display the environment of running processes. On some systems, if you set MYSQL_PWD, your password is exposed to any other user who runs ps. Even on systems without such a version of ps, it is unwise to assume that there are no other methods by which users can examine process environments.

The security of environment variables is covered in much details at https://security.stackexchange.com/a/14009/10002 and this answer also addresses the concerns mentioned in the comments. TL;DR Irrelevant for over a decade.

Having said that, the MySQL documentation also warns:

MYSQL_PWD is deprecated as of MySQL 8.0; expect it to be removed in a future version of MySQL.

To which I'll leave you with maxschlepzig's comment from below:

funny though how Oracle doesn't deprecate passing the password on the command line which in fact is extremely insecure

Answer 4

To use a file that is anywhere inside of OS, use --defaults-extra-file eg:

mysqldump --defaults-extra-file=/path/.sqlpwd [database] > [desiredoutput].sql

Note: .sqlpwd is just an example filename. You can use whatever you desire.

Note: MySQL will automatically check for ~/.my.cnf which can be used instead of --defaults-extra-file

If your using CRON like me, try this!

mysqldump --defaults-extra-file=/path/.sqlpwd [database] > "$(date '+%F').sql"

Required Permission and Recommended Ownership

sudo chmod 600 /path/.sqlpwd && sudo chown $USER:nogroup /path/.sqlpwd

.sqlpwd contents:

[mysqldump]
user=username
password=password

Other examples to pass in .cnf or .sqlpwd

[mysql]
user=username
password=password

[mysqldiff]
user=username
password=password

[client]
user=username
password=password

If you wanted to log into a database automatically, you would need the [mysql] entry for instance.

You could now make an alias that auto connects you to DB

alias whateveryouwant="mysql --defaults-extra-file=/path/.sqlpwd [database]"

You can also only put the password inside .sqlpwd and pass the username via the script/cli. I'm not sure if this would improve security or not, that would be a different question all-together.

For completeness sake I will state you can do the following, but is extremely insecure and should never be used in a production environment:

mysqldump -u [user_name] -p[password] [database] > [desiredoutput].sql

Note: There is NO SPACE between -p and the password.

Eg -pPassWord is correct while -p Password is incorrect.

Answer 5

Yeah it is very easy .... just in one magical command line no more

mysqldump --user='myusername' --password='mypassword' -h MyUrlOrIPAddress databasename > myfile.sql

and done :)

Answer 6

For me, using MariaDB I had to do this: Add the file ~/.my.cnf and change permissions by doing chmod 600 ~/.my.cnf. Then add your credentials to the file. The magic piece I was missing was that the password needs to be under the client block (ref: docs), like so:

[client]
password = "my_password"

[mysqldump]
user = root
host = localhost

If you happen to come here looking for how to do a mysqldump with MariaDB. Place the password under a [client] block, and then the user under a [mysqldump] block.

Answer 7

You can achieve this in 4 easy steps

1. create directory to store script and DB_backups
2. create ~/.my.cnf
3. create a ~/.script.sh shell script to run the mysqldump
4. Add a cronjob to run the mysql dump.

Below are the detailed steps

Step 1

create a directory on your home directory using sudo mkdir ~/backup

Step 2

In your home directory run sudo nano ~/.my.cnf and add the text below and save

[mysqldump]
#use this if your password has special characters (!@#$%^&..etc) in it
 password="YourPasswordWithSpecialCharactersInIt"
  
 #use this if it has no special characters
 password=myPassword

Step 3

cd into ~/backup and create another file script.sh add the following text to it

SQLFILE=/path/to/where/you/want/to/dump/dbname.sql
DATABASE=dbname
USER=myUsername

mysqldump --defaults-file=~/.my.cnf -u ${USER} ${DATABASE}|gzip > dbName_$(date +\%Y\%m\%d_\%H\%M).sql.gz

Step 4

In your console, type crontab -e to open up the cron file where the auto-backup job will be executed from

add the text below to the bottom of the file

0 0 * * * ./backup/script.sh

The text added to the bottom of the cron file assumes that your back up shall run daily at midnight.

That's all you need folk ;)

Answer 8

Here is a solution for Docker in a script /bin/sh :

docker exec [MYSQL_CONTAINER_NAME] sh -c 'exec echo "[client]" > /root/mysql-credentials.cnf'

docker exec [MYSQL_CONTAINER_NAME] sh -c 'exec echo "user=root" >> /root/mysql-credentials.cnf'

docker exec [MYSQL_CONTAINER_NAME] sh -c 'exec echo "password=$MYSQL_ROOT_PASSWORD" >> /root/mysql-credentials.cnf'

docker exec [MYSQL_CONTAINER_NAME] sh -c 'exec mysqldump --defaults-extra-file=/root/mysql-credentials.cnf --all-databases'

Replace [MYSQL_CONTAINER_NAME] and be sure that the environment variable MYSQL_ROOT_PASSWORD is set in your container.

Hope it will help you like it could help me !

Answer 9

I have the following.

/etc/mysqlpwd

[mysql]
user=root
password=password

With the following alias.

alias 'mysql -p'='mysql --defaults-extra-file=/etc/mysqlpwd'

To do a restore I simply use:

mysql -p [database] [file.sql]

Answer 10

Check your password!

• Took me a while to notice that I was not using the correct user name and password in ~/.my.cnf

• Check the user/pass basics before adding in extra options to crontab backup entries

• If specifying --defaults-extra-file in mysqldump then this has to be the first option

• A cron job works fine with .my.cnf in the home folder so there is no need to specify --defaults-extra-file

• If using mysqlpump (not mysqldump) amend .my.cnf accordingly

• The ~/.my.cnf needs permissions set so only the owner has read/write access with:

  chmod 600 ~/.my.cnf

Here is an example .my.cnf:

[mysql]
host = localhost
port = 3306
user = BACKUP_USER
password = CORRECTBATTERYHORSESTAPLE
[mysqldump]
host = localhost
port = 3306
user = BACKUP_USER
password = CORRECTBATTERYHORSESTAPLE
[mysqlpump]
host = localhost
port = 3306
user = BACKUP_USER
password = CORRECTBATTERYHORSESTAPLE

• The host and port entries are not required for localhost

• If your user name in linux is the same name as used for your backup purposes then user is not required

Another tip, whilst you are doing a cronjob entry for mysqldump is that you can set it to be a low priority task with ionice -c 3 nice 19. Combined with the --single-transaction option for InnoDB you can run backups that will not lock tables or lock out resources that might be needed elsewhere.

Answer 11

This is how I'm backing-up a MariaDB database using an expanding variable.

I'm using a "secrets" file in a Docker-Compose setup to keep passwords out of Git, so I just cat that in an expanding variable in the script.

NOTE: The below command is executed from the Docker host itself:

mysqldump -h192.168.1.2 -p"$(cat /docker-compose-directory/mariadb_root_password.txt)" -uroot DB-Name > /backupsDir/DB-Name_`date +%Y%m%d-%H:%M:%S`.sql

This is tested and known to work correctly in Ubuntu 20.04 LTS with mariadb-client.

Answer 12

what about --password="" worked for me running on 5.1.51

mysqldump -h localhost -u <user> --password="<password>"

Answer 13

Definitely I think it would be better and safer to place the full cmd line in the root crontab , with credentails. At least the crontab edit is restricred (readable) to someone who already knows the password.. so no worries to show it in plain text...

If needed more than a simple mysqldump... just place a bash script that accepts credentails as params and performs all amenities inside...

The bas file in simple

#!/bin/bash
mysqldump -u$1 -p$2 yourdbname > /your/path/save.sql

In the Crontab:

0 0 * * * bash /path/to/above/bash/file.sh root secretpwd 2>&1 /var/log/mycustomMysqlDump.log

Answer 14

You can specify the password on the command line as follows:

mysqldump -h <host> -u <user> -p<password> dumpfile

The options for mysqldump are Case Sensitive!