Lab #10: Create an image with VOLUME instruction

Pre-requisite:

Tested Infrastructure

Platform Number of Instance Reading Time
Play with Docker 1 5 min

Pre-requisite

  • Create an account with DockerHub
  • Open PWD Platform on your browser
  • Click on Add New Instance on the left side of the screen to bring up Alpine OS instance on the right side

Assignment

  • Create an image with VOLUME instruction
  • Finding the volume created on the host
  • Testing mount working as exepected

Create an image with VOLUME instruction

Dockerfile

FROM nginx:alpine
LABEL maintainer="Collabnix"

VOLUME /myvol
CMD [ "nginx","-g","daemon off;" ]

Building Docker image

$ docker build -t volume:v1 .

Create a container based on volume:v1 image

$ docker container run --rm -d --name volume-test volume:v1

Finding the volume created on the host

Checking the volume name of the container

$ docker container inspect -f '' volume-test
ed09456a448934218f03acbdaa31f465ebbb92e0d45e8284527a2c538cc6b016

Listout Volume in the host

$ docker volume ls
DRIVER              VOLUME NAME
local               ed09456a448934218f03acbdaa31f465ebbb92e0d45e8284527a2c538cc6b016

You will see the volume has been created.

Volume mount path in host

$ docker container inspect -f '' volume-test
/var/lib/docker/volumes/ed09456a448934218f03acbdaa31f465ebbb92e0d45e8284527a2c538cc6b016/_data

Testing mount working as exepected

Create a file in this folder

$ touch /var/lib/docker/volumes/ed09456a448934218f03acbdaa31f465ebbb92e0d45e8284527a2c538cc6b016/_data/mytestfile.txt

Checking file is there in run container

$ docker container exec -it volume-test ls myvol

Next » Create an image with EXPOSE instruction