Introduction to Docker and it ecosystem. We will explore docker basic command and how to use compose for a basic application.

1. Docker, but what it is?
Introduction to Docker and its ecosystem

2. Who am I?
• Julien Maitrehenry
• DevOps, Cloud Architect, Developer
• Co-founder @Kumojin
• Kumojin.com
• Github.com/jmaitrehenry
• jmaitrehenry.ca

3. Agenda
• What is Docker?
• Docker Compose
• Orchestration
• Docker Desktop
• Questions?
Photo by Ian Taylor on Unsplash

4. What is
Docker?

5. But what
does
« Docker »
mean?
• An Open Source project and community
• Tools from this project
• A company: Docker inc.

6. And what is
it for?

7. At the beginning
• One goal
• Linux only
• Intel CPU only
• A big and fat binnary

8. And now?
• Linux and Windows containers
• Running on Mac, Windows and Linux
• Multi Architecture (intel, armv5-8, ppc, i386)
• Split into many components
• Component standardisation (OCI, CNCF)
• Adopted by a large majority of cloud
providers

9. What is a container?
• An isolated space where an application run
• Contain everything needed to run the
application (libs, binaries, etc.)
• Own its dedicated network stack, users,
process, etc.
• Share the host kernel
• Could have some resource restriction (CPU,
Ram, etc.)

10. How is it different from a VM?

11. How to
create a
container?

12. What is an
image?
• An union of layers
• Each layers are immutable
• Each layers are reusable

13. Let’s build a Docker image
Base image
Environnent variable
Variable set during build
Working directory
Copy files into image
Command executed during build
Copy folder into image
Default command that will be
executed during a docker run

14. How to transform our file into an image?
❯ docker build -t myapp:v1.0.0 --build-arg NODE_ENV=development .
Command to build an image
Give a name and tag to the image
Set a build variable
Build context
If the Dockerfile file has another name or is located elsewhere, it must be specified with:
-f .docker/Dockerfile
Warning : the context build is always the last parameter

15. How to run a container?
- I can’t access my app from my browser
- Ctr+C do not stop my app
- The container name will be randomly generated - ex: goofy_kapitsa
❯ docker run myapp:v1.0.0
Command to run a container Image name and tag

16. How to run a container?
❯ docker run –ti -p 8080:80 --name myapp myapp:v1.0.0
Run in interactive mode and with a tty
Link container port 80 to host port 8080
Give the name myapp to the container

17. How to run a container?
❯ docker run –d -p 8080:80 --name myapp myapp:v1.0.0
Run container in background
❯ docker run –ti –p 8080:80 --name myapp --rm myapp:v1.0.0 bash
Automatically remove the container when stopped
Change the default command (CMD)

18. Summary

19. Docker Engine
• Client-Server application for managing
• Images
• Containers
• Networks
• Volumes
• Has a REST API and a CLI

20. Volume
• Keep data outside the container
• Share data with host
This Photo by Unknown Author is licensed under CC BY-SA-NC

21. Share folder/files between host and container
❯ docker run -ti --rm -v `pwd`/mydir:/data ubuntu
Command for using a volume
Local directory on host Directory in the container
Be careful when mounting a file!
Changes to file may not be reflected in container
Ex: sed, vim, VS Code

22. Using a volume
❯ docker volume create mydata
❯ docker run -ti --rm -v mydata:/data ubuntu
Command to manage volume Volume name
Volume name instead of a path

23. Network
• Allows you to:
• create isolated network
• Reproduce production network topology
• Container can communicate with each other
using by name, id or alias
• Many network type/driver available:
• Bridge (default)
• Internal
• None
• Host

24. Internal network
❯ docker network create --internal intnet
❯ docker run --network intnet curlimages/curl -m3 https://google.com
╰─❯ curl: (28) Resolving timed out after 3002 milliseconds
Command to manage networks Network type Network name
Attach the container to the intent network

25. Intra-container communication
❯ docker network create --driver bridge mynet
❯ docker run -d --network mynet --name nginx --network-alias web nginx
❯ docker run --rm --network mynet curlimages/curl -m3 http://web
Use a specific network driver
Adds an alias to the container in networks it is connected
Container name or ID also works

26. Other useful network
❯ docker run --rm --network none curl -m3 https://google.com
❯ docker run –d --network host nginx
No network isolation between host and container
Without network

27. Docker
Compose

28. Let’s build a docker compose file
DEPRECATED - No more used
Services definition
Networks definition
Volumes definition

29. Let’s build a docker compose file
Service name and its name on the network
Container image
If the container crash, docker will restart it
List of volumes to attach to the container
List of environment variables
List of networks to attach to the container

30. Let’s build a docker compose file
Override default image command
You can attach a volume to a directory in another volume
Definition for building the image
Create a dependency on another service
List of port to link to the host

31. Let’s build a docker compose file
On a separate network from the database

32. How to use a compose file?
❯ docker compose ps -a
List the containers created by compose Including those stopped
❯ docker compose logs -f [name of service(s)]
Show logs And show new logs as they come
❯ docker compose up –d [name of service(s)]
Command for compose Start service(s)
In background

33. Registry Docker
• Hosts Docker Images
• Many online registry available:
• Docker Hub
• Azure ACR
• AWS ECR
• Github Registry
• …
• Many self-hosted solutions:
• Docker Registry
• Nexus
• Artifactory
• …

34. Useful commands
❯ docker login / docker login kumojin.azurecr.io
Connect Docker to a registry
Pull an image locally
Push a local image to a registry
❯ docker push jmaitrehenry/myimage
❯ docker pull kumojin.azurecr.io/myapp/api:v1.0.0
Connect to a specific registry

35. Orchestration
• For what?
• Orchestration tools
• Cloud solutions

36. For what?
• Container supply and placement
• Health check mechanism and metrics
• Unavailability and scalability management
• Deployment management
• Service discovery and network management
• And more!

37. Orchestration tools

38. Cloud
Solutions
• Kubernetes based
• Azure: AKS
• AWS: EKS
• Google: GKE
• Container based
• Azure ACI
• AWS Fargate
• AWS ECS

39. Docker
Desktop
What is it?
For what?

40. Questions?