Restart policies in Docker - Mini Project: Build & Apply

Docker Container Restart Policies

📖 Scenario: You are managing a Docker container that runs a simple web server. You want to make sure the container restarts automatically if it stops unexpectedly, so your service stays available without manual intervention.

🎯 Goal: Learn how to set Docker container restart policies to control automatic restarts.

📋 What You'll Learn

Create a Docker container running the nginx image

Add a restart policy configuration

Use the 'always' restart policy

Verify the container restart policy is set correctly

💡 Why This Matters

🌍 Real World

Restart policies help keep important services running automatically without manual restarts, improving reliability.

💼 Career

Understanding Docker restart policies is essential for DevOps roles managing containerized applications in production.

1

Create a Docker container named mynginx using the nginx image

Run the command to create and start a Docker container named mynginx using the nginx image without any restart policy.

Docker

# Run the docker command to create and start the container named mynginx
# Your code here

Need a hint?

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

2

Add a restart policy variable called restart_policy with the value always

Define a variable called restart_policy and set it to the string always to represent the Docker restart policy you want to use.

Docker

docker run -d --name mynginx nginx
# Define restart_policy variable with value 'always'
# Your code here

Need a hint?

Write restart_policy='always' to set the restart policy variable.

3

Run the Docker container mynginx with the restart policy always

Use the docker run command with the --restart option set to the restart_policy variable value to start the container named mynginx using the nginx image.

Docker

docker run -d --name mynginx nginx
restart_policy='always'
# Run the container with --restart set to restart_policy
# Your code here

Need a hint?

Use docker run -d --name mynginx --restart $restart_policy nginx to apply the restart policy.

4

Verify the restart policy of the mynginx container

Run the command docker inspect --format='{{.HostConfig.RestartPolicy.Name}}' mynginx to display the restart policy of the container named mynginx.

Docker

restart_policy='always'
docker run -d --name mynginx --restart $restart_policy nginx
# Verify the restart policy of mynginx container
# Your code here

Need a hint?

The output should be always indicating the restart policy is set correctly.