Get docker mysql root password in a variable

Question

I created a mysql docker container mysqlcontainer using following command:

docker exec -it mysqlcontainer -d mysql/mysql-server

I run docker logs mysqlcontainer and get the following:

[Entrypoint] GENERATED ROOT PASSWORD: FB=?ySG5,3#@kur&,Wj459fk2Gy2C_O8

[Entrypoint] ignoring /docker-entrypoint-initdb.d/*

[Entrypoint] MySQL init process done. Ready for start up.
2022-04-22T07:49:23.295242Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld:   

I want to put this generated root password into a variable so that I can use this variable in shell script.

I used the following command to get password but how can I put the password into a variable

docker logs mysqlcontainer 2>&1 | grep GENERATED
[Entrypoint] GENERATED ROOT PASSWORD: FB=?ySG5,3#@kur&,Wj459fk2Gy2C_O8

Answer 1

For those not familiar with awk, this is a non awk version of the solution. Also declaring and using a variable in one instruction is discouraged by shellcheck.net, I prefer separating the instructions

MYVAR=$(docker logs mysqlcontainer 2>&1 | grep 'GENERATED ROOT PASSWORD' | cut -f5 -d" ")
export MYVAR

Answer 2

When you say you want the password in a variable, I assume that you mean a shell variable. If so, you can do something like this

export myvar=$(docker logs mysqlcontainer 2>&1 | awk '/GENERATED ROOT PASSWORD/ {print $5}')

then

echo $myvar

should give you the password.

It works by looking for the string 'GENERATED ROOT PASSWORD' in the logs and setting the variable to the 5th word in that line.