Container states (created, running, paused, stopped) in Docker - Mini Project: Build & Apply

Container states (created, running, paused, stopped)

📖 Scenario: You are learning how to manage Docker containers. Containers can be in different states like created, running, paused, or stopped. Understanding these states helps you control your applications better.

🎯 Goal: Build a simple Docker workflow to create a container, start it, pause it, and then stop it. You will check the container's state at each step.

📋 What You'll Learn

Use the docker command line tool

Create a container from the alpine image

Start, pause, and stop the container using Docker commands

Check the container state using docker ps -a

💡 Why This Matters

🌍 Real World

Managing container states is essential for running applications reliably in development and production environments.

💼 Career

DevOps engineers and system administrators use these commands daily to control application lifecycles and troubleshoot issues.

1

Create a Docker container

Use the command docker create --name mycontainer alpine sleep 3600 to create a container named mycontainer from the alpine image.

Docker

# Use docker create to make a container named mycontainer from alpine
# Your code here

Need a hint?

This command creates a container but does not start it. The container will be in the 'created' state.

2

Start the Docker container

Use the command docker start mycontainer to start the container named mycontainer.

Docker

docker create --name mycontainer alpine sleep 3600
# Start the container named mycontainer
# Your code here

Need a hint?

Starting the container changes its state to 'running'.

3

Pause the Docker container

Use the command docker pause mycontainer to pause the running container named mycontainer.

Docker

docker create --name mycontainer alpine sleep 3600
docker start mycontainer
# Pause the container named mycontainer
# Your code here

Need a hint?

Pausing a container freezes its processes but keeps it in memory.

4

Stop the Docker container and check its state

Use the command docker stop mycontainer to stop the container named mycontainer. Then use docker ps -a --filter name=mycontainer --format "{{.Names}} {{.Status}}" to display the container's name and current state.

Docker

docker create --name mycontainer alpine sleep 3600
docker start mycontainer
docker pause mycontainer
# Stop the container named mycontainer
# Show the container's name and status
# Your code here

Need a hint?

Stopping the container ends its processes and changes its state to 'exited' or 'stopped'. The docker ps -a command shows all containers and their states.