/hello-docker

Getting started with docker

Primary LanguageJavaScript

Hello Docker

Getting started with Docker

Course

Docker and Kubernetes: The complete Guide

Notes

What is a Container?

A container is an instance of an image

What is an Image?

A image is a executable package that includes everything needed to run an application (Dockerfile)

Steps for creating a Dockerfile

  1. Specify a base image
  2. Run some commands to install additional programs
  3. Specify a command to run on container startup

steps for creating a Nodejs application

  1. Create a Node.js app
  2. Create a Dockerfile
  3. Build image from dockerfile
  4. Run image as container
  5. Test the app

Docker commands

  • docker create <image-name>

  • docker start <container id> Also restart a stopped cotainer

    • -a output logs (stdout)

  • docker run <image-name> <command> create and run a container

    • docker run -it <image-name> sh Start a container in a shell and get full terminal access inside the context of the container, which is usefull for debugging.

  • docker run -p 5000:3000 -d <username>/image-name

    • -p Port mapping
    • -d Run in detached mode

  • docker ps list al of the running cotainers

    • --all list all of containers created`

  • docker system prune Remove all stopped containers

  • docker logs <container id> Retrive log outputs

  • docker stop <container-id> stop gracefully SIGTERM, wait 10s

  • docker kill <container-id> stop inmiadiatly SIGKILL

  • docker exec -it <container-id> <command> Execute an additional command in a container

    • -i STDIN
    • -t STDOUT

  • docker build -t <username/image-name:latest> . Building and tagging an image

  • docker image ls list images

  • docker push username/repository:tag Upload a tagged image to the repository (Docker hub)

Docker Compose

Separate CLI that gets installed along with Docker, it's used to start up multiple docker containers at the same time in an application.

steps to run an application with compose

  1. Define the app environment with Dockerfile so it can be reproduced anywhere.
  2. Define the services that make up the app in a docker-compose.yml file so they can be run together in an isolated environment.
  3. Run docker-compose up and Compose starts and runs the entire app.

commands

  • docker-compose up

    • --build This command is like docker build . and docker run myimage together
    • -d Run in detached mode

  • docker-compose down

  • docker-compose ps this command must be executed within a folder that has a docker-compose.yml file, otherwise, it'll throw an error.