Challenge, Easy,  on  Containers

Gracefully Stop a Container With a Lengthy Shutdown Sequence

When you docker stop a container, Docker sends a termination signal (defaults to SIGTERM) to the main process and waits for it to exit. If the process doesn't exit within a certain timeout, Docker sends a follow-up SIGKILL signal to forcefully terminate it.

In this challenge, a container named slow-app-1 is running an application that handles SIGTERM gracefully but takes a relatively long time to complete its shutdown sequence.

Your task is to stop the container so that it exits cleanly with exit code 0. Sounds too simple? Beware, running docker stop slow-app-1 won't cut it - the container will be killed before its shutdown sequence completes.

Hint: Exploring docker stop options

The docker stop command has a flag that controls how long Docker waits before sending SIGKILL. Check docker stop --help to find it.

How to Author Challenges on iximiuz Labs

Instead of providing a subpar online editing experience, iximiuz Labs offers a helper CLI tool called labctl, allowing you to use your favorite text editor (or a full-featured IDE) to write content from the comfort of your local machine.

Install labctl CLI

curl -sf https://labs.iximiuz.com/cli/install.sh | sh

This will download and install the latest version of the labctl CLI. You only need to do this once per workstation.

Authorize labctl

labctl auth login

This will open a browser window asking you to authorize labctl to access your account. You need to do it after a fresh install of labctl and repeat it whenever the auth session expires.

Pull challenge content

labctl content pull challenge docker-graceful-container-shutdown

This will create a local copy of the challenge content in a directory named docker-graceful-container-shutdown. You only need to do this once per challenge.

Stream your changes

labctl content push -fw challenge docker-graceful-container-shutdown

Run this command in a separate terminal to continuously upload your changes to the server while editing the challenge in your favorite text editor or IDE.

You can also use labctl to create, list, and delete your content. Learn more about the available commands: labctl content --help

Start challenge