We mostly use 101 course from
https://www.docker.com/101-tutorial
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OS-level virtualization
https://en.wikipedia.org/wiki/OS-level_virtualization
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Docker:
https://en.wikipedia.org/wiki/Docker_(software)
SW:
Docker Daemon 
Docker client program
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Objecs:
Docker container
Docker image
Docker service (we will not speak about this today)
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Registries:
Docker registry (main ones: default one Docker Hub and Docker Cloud)
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Tools:
Docker Dashboard
Docker Compose
Docker Swarm (we will not speak about this today)
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Child commands
https://docs.docker.com/engine/reference/commandline/docker/
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Working with docker command:
- Run Ubuntu container with bash
docker run -it ubuntu
docker run -it ubuntu echo AAA
- Run docker tutorial command (in docker)
This demonstrates port mapping
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Very basic Workflows
docker images
Dockerfile
docker build -t getting-started .
docker ps
docker run -dp 3000:3000 getting-started
docker stop <the-container-id>
docker rm <the-container-id>
docker rm -f <the-container-id>
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Docker volumes - Named volumes
docker volume create todo-db
docker run -dp 3000:3000 -v todo-db:/etc/todos getting-started
docker volume inspect todo-db
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Docker volumes - Bind Mounts
docker run -dp 3000:3000 \
    -w /app -v "$(pwd):/app" \
    node:12-alpine \
    sh -c "yarn install && yarn run dev"
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Docker networking
docker network create todo-app
docker run -d \
    --network todo-app --network-alias mysql \
    -v todo-mysql-data:/var/lib/mysql \
    -e MYSQL_ROOT_PASSWORD=secret \
    -e MYSQL_DATABASE=todos \
    mysql:5.7

docker run -dp 3000:3000 \
  -w /app -v "$(pwd):/app" \
  --network todo-app \
  -e MYSQL_HOST=mysql \
  -e MYSQL_USER=root \
  -e MYSQL_PASSWORD=secret \
  -e MYSQL_DB=todos \
  node:12-alpine \
  sh -c "yarn install && yarn run dev"
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Docker Compose
docker-compose.yml
docker-compose up -d
docker-compose logs
docker-compose down 
	(--volumes)
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Layers and good practices
How layers work, Layer caching
Good practices writing Dockerfile

docker image history

docker scan getting-started
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Docker registry
docker tag getting-started YOUR-USER-NAME/getting-started
docker push YOUR-USER-NAME/getting-started
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Discuss typical use cases:
Production 
	- clean and well defined enviroment 
		- you want to test in a clone of production enviroment, containers help a lot with this
	- standardized format that allows to other tools (e.g. container orchestration)	
Build
	- do need to setup build dependencies
	- you can test in well defined enviroment
https://www.airpair.com/docker/posts/8-proven-real-world-ways-to-use-docker
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Insights into how the containers work:
https://www.youtube.com/watch?v=8fi7uSYlOdc
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