Docker stop/start resets to initial passwords - docker

Question

I've just started using docker by copy-pasting pre-made repos from github.
Here is the scenario and steps:
I've passed mysql/shell root password via environment variable -e and these passwords are set as expected inside entry.sh.
I then go inside container and reset shell/mysql root password to something different.
Now the main issue, each time I do docker stop + start from host, it resets passwords to the initial ones of step1.
Please suggest the changes so it retain the modified step2 passwords even I do docker start/stop.
Used entry.sh and dockerfile scripts can be checked from this github repo.
Thanks.

Answer 1

I just noticed that the entry.sh will always update the root password with $MYSQL_RANDOM_ROOT_PASSWORD on docker start. So assuming we already persist the /var/lib/mysql in the host, we can edit the entry.sh a bit to only update the password when /var/lib/mysql doesn't exists:
#!/bin/sh
# start apache
echo "Starting httpd"
httpd
echo "Done httpd"
# check if mysql data directory is nuked
# if so, install the db
echo "Checking /var/lib/mysql folder"
if [ ! -f /var/lib/mysql/ibdata1 ]; then
echo "Installing db"
mariadb-install-db --user=mysql --ldata=/var/lib/mysql > /dev/null
echo "Installed"
# from mysql official docker repo
if [ -z "$MYSQL_ROOT_PASSWORD" -a -z "$MYSQL_RANDOM_ROOT_PASSWORD" ]; then
echo >&2 'error: database is uninitialized and password option is not specified '
echo >&2 ' You need to specify one of MYSQL_ROOT_PASSWORD, MYSQL_RANDOM_ROOT_PASSWORD'
exit 1
fi
# random password
if [ ! -z "$MYSQL_RANDOM_ROOT_PASSWORD" ]; then
echo "Using random password"
MYSQL_ROOT_PASSWORD="$(pwgen -1 32)"
echo "GENERATED ROOT PASSWORD: $MYSQL_ROOT_PASSWORD"
echo "Done"
fi
tfile=`mktemp`
if [ ! -f "$tfile" ]; then
return 1
fi
cat << EOF > $tfile
USE mysql;
DELETE FROM user;
FLUSH PRIVILEGES;
GRANT ALL PRIVILEGES ON *.* TO 'root'#'%' IDENTIFIED BY "$MYSQL_ROOT_PASSWORD" WITH GRANT OPTION;
GRANT ALL PRIVILEGES ON *.* TO 'root'#'localhost' WITH GRANT OPTION;
UPDATE user SET password=PASSWORD("") WHERE user='root' AND host='localhost';
FLUSH PRIVILEGES;
EOF
echo "Querying user"
/usr/bin/mysqld --user=root --bootstrap --verbose=0 < $tfile
rm -f $tfile
echo "Done query"
# setting ssh root password
if [ -z "$SSH_ROOT_PASSWORD" ]; then
echo >&2 'You need to specify SSH_ROOT_PASSWORD'
exit
fi
# Set root password to root, format is 'user:password'.
echo "root:$SSH_ROOT_PASSWORD" | chpasswd
fi;
echo "Generating ssh keys"
if [ ! -f "/etc/ssh/ssh_host_rsa_key" ]; then
# generate fresh rsa key
ssh-keygen -f /etc/ssh/ssh_host_rsa_key -N '' -t rsa
fi
if [ ! -f "/etc/ssh/ssh_host_dsa_key" ]; then
# generate fresh dsa key
ssh-keygen -f /etc/ssh/ssh_host_dsa_key -N '' -t dsa
fi
#prepare run dir
if [ ! -d "/var/run/sshd" ]; then
mkdir -p /var/run/sshd
fi
ssh-keygen -A
/usr/sbin/sshd
# start mysql
# nohup mysqld_safe --skip-grant-tables --bind-address 0.0.0.0 --user mysql > /dev/null 2>&1 &
echo "Starting mariadb database"
exec /usr/bin/mysqld --user=root --bind-address=0.0.0.0
Basically we just move this block of code to the if block above it