Give ability to store data permanent. Because container store data Temporary. or Docker volume is ability to give backup of data to host machine.
-v is cmd for docker volume.
docker system prune -y
// this will delete which container is stop or taking unwanted space.
docker run -d --name mysql -e MYSQL_ROOT_PASSWORD=root mysql:latest
// this will launch mysql container with this cmd.
docker exec -it <cont_id> bash
// this will enter into mysql container and execute bash shell.
mysql -u root -p
// enter into mysql program in cli mode.
show databases;
// to see all databases.
create database kyc_devops;
//creating new databases kyc devops.
use kyc_devops;
//use that databases.
CREATE TABLE messages( id INT AUTO_INCREMENT PRIMARY KEY, message TEXT);
//Created table message with auto increment.
insert into messages (message) values ("Kyc Submitted");
//by this cmd u will inserting Kyc Submitted msg into message column and in messages database.
select * from messages;
// by this you will retrive all data from messages database.
exit
//this will exit from mysql.
exit
//this will exit from mysql container.
docker ps // container is running?
docker stop <cont_id> // stop mysql container.
docker rm <cont_id> //remove mysql container.
//by this three cmd i remove the container and delete it
docker ps //now what i see that container is not running
docker run -d --name mysql -e MYSQL_ROOT_PASSWORD=root mysql:latest
//so what i did that i launch container again with same cmd.
docker exec -it <cont_id> bash
//enter again into container.
mysql -u root -p
//login int mysql database.
show databases;
//what we see that our database kyc_devops is not there and so our database is gone.
exit //exit from mysql
exit //exit from container
docker ps // container is running?
docker stop <cont_id> // stop mysql container.
docker rm <cont_id> //remove mysql container.
//by this three cmd i remove the container and delete it
So For this is there is solution called docker volumne.
mkdir mysql-volume // create a folder in host machine for backup.
cd mysql-volume // go inside that folder
pwd //see path & copy that for mapping with container
/home/ubuntu/mysql-volume
docker run -d -v /home/ubuntu/mysql-volume:/var/lib/mysql --name mysql -e MYSQL_ROOT_PASSWORD=root mysql:latest
//by this cmd -v is use to map host folder with the mysql folder where it store data eg.(/var/lib/mysql)
//interview question--> what is flag that use to create volumne in docker container?
docker exec -it <cont_id> bash
// this will enter into mysql container and execute bash shell.
mysql -u root -p
// enter into mysql program in cli mode.
show databases;
// to see all databases.
create database kyc_devops;
//creating new databases kyc devops.
use kyc_devops;
//use that databases.
CREATE TABLE messages( id INT AUTO_INCREMENT PRIMARY KEY, message TEXT);
//Created table message with auto increment.
insert into messages (message) values ("Kyc Submitted");
//by this cmd u will inserting Kyc Submitted msg into message column and in messages database.
select * from messages;
// by this you will retrive all data from messages database.
exit
//this will exit from mysql.
exit
//this will exit from mysql container.
cd mysql-volume/ //got inside this folder to check your data is map or not.
ls // you will see some files.
docker ps // container is running?
docker stop <cont_id> // stop mysql container.
docker rm <cont_id> //remove mysql container.
//by this three cmd i remove the container and delete it
//now we have deleted container lets create new container with -v again and see what happen.
docker run -d -v /home/ubuntu/mysql-volume:/var/lib/mysql --name mysql -e MYSQL_ROOT_PASSWORD=root mysql:latest
//creating new container again with -v to same folder path /home/ubuntu/mysql-volume.
docker exec -it <cont_id> bash
// this will enter into mysql container and execute bash shell.
show databases;
// to see all databases.
use kyc_devops;
//use that databases.
show tables;
//to see all tables which were created in past.
select * from messages;
// by this you will retrive all data from messages database.
// here u will see your data so this is how docker volumne is use for container for persistence the data.
docker volume ls
//see all volume in docker
docker volume inspect <id>
//detail about volume
docker volume create mysql-data
//creating volume name mysql-data
//mysql data is logical entity
//there is two volume first is unamed volume where u give path eg(-v) and
second is named volume where u did not give the path just give name eg.mysql-data.
docker volume ls
//to see volume mysql-data volumne is created or not
docker volume inspect mysql-data
//to see path where mysql-data is mouted. you will see Mountpoint key and value will be your path.
we can do like this also
docker volume create nginx-volume
docker run -d -v nginx-volume:/var -p 80:80 nginx:latest
//running container with logical volume which is nginx-volume.
docker volume ls
//see nginx-volume is there or not.
docker inspect nginx-volume
//to check mouted path folder to it.
sudo su
//switch to user
cd /var/lib/docker/volumes/nginx-volume/_data
//copy and paste that path
ls
//to check data is presented or not.
docker volume prune // to remove the uneccessary volume
now lets start with docker networking
there is 7 types of network in docker
clone the repository.