Docker Volumes & Networking

gistfile1.txt

Docker Volumes & Networking

2 Types of Mounts:

1.-Volume Mounting:
-When you use the command:
docker volume create “data_volume”

docker volume ls

-> docker volume inspect (Volume name)
-> it will create a Persistent Volume in the route: /var/lib/docker/volumes/data_volume



and then you use the command:
docker run -v data_volume:/var/lib/mysql mysql

-> you Mount the Volume inside the Docker Container (the “write-read layer” ),  so with that the Data will persist event the Container is deleted 
* this route in the container:  /var/lib/mysql  is where is stored the Mysql data


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2.-Bind Mounting:

is when we use this command:
docker run -v /data/mysql:/var/lib/mysql -d mysql

or in a Verbose and easy to read way the command is:
docker run --mount type=bind,source=/data/mysql,target=/var/lib/mysql -d mysql
docker run -d --mount type=volume,src=sample-volume,target=/usr/share/nginx/html mysql


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Docker Default Networks

By default once docker is installed come w 3 networks: Bridge, none and Host. You can see it using:   docker network ls

To see the default configuration of the BRIDGE network:    docker network inspect bridge


And any container will automatically use the default Bridge network!
But also we can create other Bridge Networks using:     docker network create --driver bridge (network name)

To see the network settings of each Container, use the command:     docker inspect [image ID]



Docker has an embedded DNS, so instead of use the IP of a specific container, you use the “name of the container” instead.


and to attach a newly created network to the docker run command: 

docker run -d -e MYSQL_ROOT_PASSWORD=db_pass123 --name mysql-db --network (network name XYZ)  mysql

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*** you can link 2 containers using the docker run parameter “--LINK (source container):(recipient container)”:    
--link mysql-db:mysql-db

Don’t forget the 2 containers have to share and be in the same network!

for example:
docker run --network=(network name XYZ) -e DB_Host=mysql-db -e DB_Password=db_pass123 -p 38080:8080 --name webapp --link mysql-db:mysql-db -d kodekloud/simple-webapp-mysql

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para ver la lista de containers con sus respectivos IPs:
docker network inspect bridge | jq .[0].Containers



para desconectarse de una network spacifica:
docker network disconnect (Network name) (Container name)

Y

para conectarse a una network spacifica:
docker network connect (Network name) (Container name)

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Para eliminar container completamente sin dejar registros:
docker rm -f app-1



Docker Port-forwarding

docker run -p 80:80 (docker image)



 docker run -v /root/app-data:/usr/share/nginx/html -p 80:80 --name sample-app nginx:alpine


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