Scenario:

You need to create a Docker volume named myvol and demonstrate cross-platform consistency - that data written from one container is readable by a different container using a different base image.

Task:

Create a Docker volume named myvol, mount it at /data, write a file hello.txt to it from an ubuntu:latest container, then read the same file from an alpine:latest container, ensuring the file exists at /var/lib/docker/volumes/myvol/_data/hello.txt on the host during validation.

Example:

# Writing from Ubuntu
ubuntu@container:/# echo "Hello from Ubuntu!" > /data/hello.txt

# Reading from Alpine
/ # cat /data/hello.txt
Hello from Ubuntu!

Step 1: Create the volume

docker volume create myvol

Creates the named volume.

Step 2: Inspect the volume

docker volume inspect myvol

View volume details including Mountpoint.

Step 3: Run Ubuntu container and write a file to the volume

docker run --rm -v myvol:/data ubuntu sh -c 'echo "Hello from Ubuntu!" > /data/hello.txt'

Mounts volume to /data in Ubuntu container and writes hello.txt.

Step 4: Run Alpine container and read the file from the volume

docker run --rm -v myvol:/data alpine cat /data/hello.txt

Should output: Hello from Ubuntu! (proving cross-platform consistency)

Step 5: Test data persistence across different platforms

docker run --rm -v myvol:/data alpine sh -c 'echo "Additional line from Alpine" >> /data/hello.txt'
docker run --rm -v myvol:/data ubuntu cat /data/hello.txt

Should show both lines (Ubuntu original + Alpine addition), proving cross-platform consistency.