Port mapping with -p flag in Docker - Mini Project: Build & Apply

Port mapping with -p flag

📖 Scenario: You want to run a web server inside a Docker container and make it accessible from your computer's browser.To do this, you need to map the container's internal port to a port on your computer.

🎯 Goal: Learn how to use the -p flag in the docker run command to map ports from the container to your computer.

📋 What You'll Learn

Create a Docker container running the nginx web server.

Map the container's port 80 to your computer's port 8080 using the -p flag.

Verify the port mapping by running the container and checking the output.

💡 Why This Matters

🌍 Real World

Port mapping is essential when running web servers or services inside containers so you can access them from your computer or network.

💼 Career

Understanding port mapping helps you deploy containerized applications and troubleshoot network access issues in real environments.

1

Create a Docker container running nginx

Write the docker run command to start a container named mynginx using the nginx image without any port mapping.

Docker

# Write the docker run command to start nginx container named mynginx
# Your code here

Need a hint?

Use docker run --name mynginx -d nginx to start the container in detached mode.

2

Add port mapping with -p flag

Modify the docker run command to map port 8080 on your computer to port 80 inside the container using the -p flag.

Docker

docker run --name mynginx -d nginx
# Add the -p flag to map port 8080 on host to port 80 in container
# Your code here

Need a hint?

Use -p 8080:80 to map ports.

3

Run the container with port mapping

Run the docker run command with the -p 8080:80 flag and container name mynginx to start the nginx server with port mapping.

Docker

docker run --name mynginx -d -p 8080:80 nginx
# Run the container with port mapping
# Your code here

Need a hint?

Use the same command as before to run the container.

4

Verify port mapping with docker ps

Write the docker ps command to list running containers and show the port mapping for mynginx.

Docker

docker run --name mynginx -d -p 8080:80 nginx
# Write the docker ps command to verify port mapping
# Your code here

Need a hint?

Use docker ps to see running containers and their port mappings.