Named volumes for data sharing in Docker - Mini Project: Build & Apply

Named volumes for data sharing

📖 Scenario: You are setting up two Docker containers that need to share data. To do this safely and easily, you will use a named volume. This volume will store files that both containers can access.

🎯 Goal: Create a Docker named volume called shared_data. Then, configure two containers to use this volume so they can share files. Finally, verify the shared data by listing the files inside the volume from one container.

📋 What You'll Learn

Create a named volume called shared_data

Run a container named writer that uses the shared_data volume and writes a file inside it

Run a container named reader that uses the shared_data volume and lists the files inside it

Print the output of the reader container showing the shared file

💡 Why This Matters

🌍 Real World

Named volumes are used in real projects to share data between containers, like sharing database files or configuration.

💼 Career

Understanding named volumes is important for DevOps roles to manage persistent data and container communication.

1

Create a named volume called shared_data

Write the Docker command to create a named volume called shared_data.

Docker

# Your code here

Need a hint?

Use docker volume create followed by the volume name.

2

Run a container named writer that uses the shared_data volume and writes a file

Write the Docker command to run a container named writer using the shared_data volume mounted at /data. Inside the container, create a file named hello.txt with the content Hello from writer. Use the alpine image and run the command sh -c "echo 'Hello from writer' > /data/hello.txt".

Docker

docker volume create shared_data
# Your code here

Need a hint?

Use docker run --rm --name writer -v shared_data:/data alpine sh -c "echo 'Hello from writer' > /data/hello.txt".

3

Run a container named reader that uses the shared_data volume and lists files

Write the Docker command to run a container named reader using the shared_data volume mounted at /data. Use the alpine image and run the command ls /data to list files inside the volume.

Docker

docker volume create shared_data
docker run --rm --name writer -v shared_data:/data alpine sh -c "echo 'Hello from writer' > /data/hello.txt"
# Your code here

Need a hint?

Use docker run --rm --name reader -v shared_data:/data alpine ls /data.

4

Print the output of the reader container showing the shared file

Run the command to list files inside the shared_data volume from the reader container and print the output. The output should show hello.txt.

Docker

docker volume create shared_data
docker run --rm --name writer -v shared_data:/data alpine sh -c "echo 'Hello from writer' > /data/hello.txt"
docker run --rm --name reader -v shared_data:/data alpine ls /data
# Your code here

Need a hint?

Run the reader container with ls /data and check the output.