Introduction to Docker

Transcript

1. Introduction to Ulugbek Miniyarov Software Architect @ ENUYGUN
2. A brief explanation of containers An image is a lightweight, stand-alone, executable package that includes everything needed to run a piece of software, including the code, a runtime, libraries, environment variables, and config files. A container is a runtime instance of an image – what the image becomes in memory when actually executed. It runs completely isolated from the host environment by default, only accessing host files and ports if configured to do so. Containers run apps natively on the host machine’s kernel.
3. Containers vs Virtual Machines
4. What is an image? • An image is a collection of files + some meta data. (Technically: those files form the root filesystem of a container.) • Images are made of layers, conceptually stacked on top of each other. • Each layer can add, change, and remove files. • Images can share layers to optimize disk usage, transfer times, and memory use. Example: Ubuntu > Varnish > Apache > PHP-FPM > Symfony > Dependencies > Application > Configuration
5. Metaphor: Object-Oriented Programming • Images are conceptually similar to classes. • Layers are conceptually similar to inheritance. • Containers are conceptually similar to instances.
6. Image namespaces There are three namespaces: • Official images: ubuntu, busybox ... • User (and organizations) images: miniyarov/symfony • Self-hosted images: registry.enuygun.com/flight/image
7. Running with Docker
8. Committing your first Docker container
9. Dockerfile • Manual process = bad. • Automated process = good. Let’s learn how to automate the build process by writing a Dockerfile. $ docker build -t figlet . $ docker run -it figlet root@<imageId>:/# figlet hello
10. Containers as services: Docker Compose A docker-compose.yml file is a YAML file that defines how Docker containers should behave
11. Docker Swarm (Container Orchestration)
12. Resources for further study: Official Get Started: https://docs.docker.com/get-started/ Another Good Explanation: http://view.dckr.info/DockerIntro.pdf Another Container Orchestration by Google: Kubernetes.io
13. Thank you!