Let's discuss Docker basics

This is part of a series of discussions regarding Deploying TaskMuncher, a React and Node application, to a Multi-Container Docker Environment at AWS using Dockerhub and Travis CI

For more details, please see Overview of Create Multi-Container Docker TaskMuncher Application at AWS

Docker

• Docker Docs
• Explore Dockerhub
• Docker Run Reference
• Docker Labs

Docker is a software platform that allows you to build, test, and deploy applications quickly. Docker packages software into standardized units called containers that have everything the software needs to run including libraries, system tools, code, and runtime. Using Docker, you can quickly deploy and scale applications into any environment and know your code will run.

Docker works by providing a standard way to run your code. Docker is an operating system for containers. Similar to how a virtual machine virtualizes (removes the need to directly manage) server hardware, containers virtualize the operating system of a server. Docker is installed on each server and provides simple commands you can use to build, start, or stop containers.

When you are running Docker, every single container you are running is running inside of a Virtual Machine running Linux.

A Docker Image is a single file with all the dependencies and configuration required to run a program.

A Docker container is used to run a single instance of a Docker image.

Each running Docker container has its own file system.

Docker Cheat Sheets

• Docker Cheat Sheet
• The Ultimate Docker Cheat Sheet
• Docker CLI Cheat Sheet

Docker Compose Cheat Sheets

• docker-compose Cheat Sheet
• Docker Compose Cheat sheet

Install Docker on Mac

Docker Desktop for Mac

DockerHub has a library of containers.

• Get Docker
• Downloads Docker.dmg
• Install

Docker.app is installed in /Applications

Docker downloads are stored in $HOME/Library/Containers/com.docker.docker/Data

Start Docker Desktop App

Click whale icon in top status bar to execute Docker.app

Login using Docker Id and Password

Visual Studio Docker Hub Extension

• Go to Extensions and search for @id:ms-azuretools.vscode-docker, which will find Docker 1.11.0
• Install

Click the whale icon in left menu.

Under Registries:

• click Connect Registry
• enter Id and Password

Visual Studio yaml Extension

• Go to Extensions and search for redhat.vscode-yaml which finds YAML by Red Hat
• Install

settings.json

"[yaml]": {
	"editor.autoIndent": "advanced"
}

Basic Docker

docker version

docker info

docker images lists all images stored locally

docker run <image-name> creates and runs a container using the specified image

docker ps lists all the containers currently up

docker ps -a lists all the containers, also the ones stopped

docker rm <container-name> stops and removes the specified container

docker pull <image-name> downloads the specified image from Docker Hub

docker rmi <image-name> removes the specified image from your machine

docker system prune remove stopped containers

docker logs <container id> retrieves Log Outputs or see $HOME/Library/Containers/com.docker.docker/Data/log/

docker stop <container id> sends a SIGTERM signal to the container

docker kill <container id> sends a SIGKILL to the primary task in the container, will stop immediately.

docker run -it <container id> sh starts with a shell

• -i attach to stdin
• -t ensure text output is in a nice format
• To exit the container, control d

docker exec -it <container id> <command> execute command in a running container

Basic Docker Compose

Docker compose makes it a lot easier to configure and run a docker container.

docker-compose -v

docker-compose up,

docker-compose up -d

docker-compose up --build

docker-compose down

docker-compose ps

Simple example of running a Docker container

docker run -d -p 80:80 docker/getting-started

which creates an image docker/getting-started in container gracious_einstein

To run the app

http://localhost:80