Docker Pull Image from Repository

Introduction

In this lab, you will immerse yourself in an ancient maze, taking on the role of a treasure hunter tasked with the challenge of retrieving a valuable hidden treasure deep within the labyrinth. As the treasure hunter, your objective is to navigate through the maze to locate the treasure, drawing parallels to the process of pulling Docker images from a repository.

Skills Graph

Exploring the Maze

Imagine yourself standing at the entrance of a mystical maze, ready to embark on a thrilling quest for hidden treasure. Docker, much like this maze, holds a world of possibilities waiting to be explored. In this step, let's dive into the labyrinth of containers and images, setting the stage for an exciting journey into the realm of Docker.

Navigating the Repository Realm

Just as a treasure hunter meticulously studies maps and clues, you will begin your Docker journey by navigating the repository – the treasure trove of container images. The repository is akin to a vast library, housing a myriad of Docker images, each serving a unique purpose.

Your first task is to identify the image that aligns with your quest. Much like choosing the right tool for the job, selecting the perfect Docker image is crucial for a successful expedition. Utilize commands like docker search to sift through the repository, unveiling the hidden gems that await your discovery.

docker search <keyword>

Replace <keyword> with terms relevant to your quest, and witness as Docker unveils a list of potential images, each holding the promise of fulfilling your objectives.

For example, search for the image that named alpine, you can use the following command.

$ cd ~/project
$ docker search alpine

Example

If you run the command correctly, the output must be like the following:

$ docker search alpine
NAME                               DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
alpine                             A minimal Docker image based on Alpine Linux…   10557     [OK]
alpinelinux/docker-cli             Simple and lightweight Alpine Linux image wi…   9
alpinelinux/alpine-gitlab-ci       Build Alpine Linux packages with Gitlab CI      3
alpinelinux/gitlab-runner-helper   Helper image container gitlab-runner-helper …   4
alpinelinux/rsyncd                                                                 2
alpinelinux/unbound                                                                9
alpinelinux/alpine-drone-ci        Build Alpine Linux packages with drone CI       0
alpinelinux/docker-compose         docker-compose image based on Alpine Linux      2
alpinelinux/apkbuild-lint-tools    Tools for linting APKBUILD files in a CI env…   0
alpinelinux/gitlab-runner          Alpine Linux gitlab-runner (supports more ar…   5
alpinelinux/ansible                Ansible in docker                               9
alpinelinux/darkhttpd                                                              2
alpinelinux/docker-alpine                                                          0
alpinelinux/golang                 Build container for golang based on Alpine L…   2
alpinelinux/alpine-docker-gitlab   Gitlab running on Alpine Linux                  0
grafana/alpine                     Alpine Linux with ca-certificates package in…   6
alpinelinux/docker-abuild          Dockerised abuild                               0
alpinelinux/alpine-www             The Alpine Linux public website (www.alpinel…   0

Obtaining the Map

As you delve deeper into the maze of Docker, you stumble upon an ancient map—a key to unraveling the secrets hidden within. This map, much like a Docker image, holds the promise of guidance on your quest for the ultimate treasure.

Retrieving the Map (Docker Image)

docker pull <keyword>

Execute the docker pull command with the name of the identified image, just as you would unfold the ancient map to reveal its intricate details. This action fetches the image, equipping you with the essential knowledge required for the journey ahead.

In the Docker realm, the map image acts as a blueprint, providing insights into the configuration, dependencies, and intricacies of your containerized environment. It serves as your guiding light, steering you through the labyrinth of containers.

In this step, you must to pull the image named alpine. You can run the command following in the terminal:

$ docker pull alpine

Example

If you run the command correctly, the output must be like the following:

$ docker pull alpine
docker pull alpine
Using default tag: latest
latest: Pulling from library/alpine
59bf1c3509f3: Pull complete
Digest: sha256:21a3deaa0d32a8057914f36584b5288d2e5ecc984380bc0118285c70fa8c9300
Status: Downloaded newer image for alpine:latest
docker.io/library/alpine:latest

Navigating the Corridors

In the heart of the Docker maze, you find yourself at a crossroads, surrounded by corridors leading to different realms. Your next task is to traverse these corridors by bringing your Docker container to life. This step mirrors the process of running a container from the image you've pulled, initiating a journey through the intricate corridors of the containerized environment.

Unleashing Container Energy

docker run -it --name <container_name> <map_image> <command>

Execute the docker run command, setting the stage for your container to come to life. The -it flags grant you interactive access, allowing you to navigate the container corridors seamlessly. Replace <container_name> with a name that resonates with your quest, and replace <command> with a correct Linux shell command that you want the container running, making your container an identifiable entity in this vast Docker maze.

In this step, you must run a container that named alpine_container and let it execute the /bin/sh command. You can execute the following command in the terminal:

docker run -it --name alpine_container alpine /bin/sh

Example

If you run the command correctly, the output must be like the following:

$ docker run -it --name alpine_container alpine /bin/sh
/ ## ls -a
. .dockerenv dev home media opt root sbin sys usr
.. bin etc lib mnt proc run srv tmp var
/ ## ```

Summary

In this lab, you embarked on a thrilling adventure through an ancient maze to retrieve a hidden treasure, drawing parallels with the process of pulling Docker images from a repository. By executing each step, you gained hands-on experience in navigating the Docker ecosystem, mirroring the exploration of the maze, and ultimately acquiring valuable insights into the world of containerization.