Prerequisites

Docker installed

docker info

❯ docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Build with BuildKit (Docker Inc., v0.5.1-docker)
  compose: Docker Compose (Docker Inc., 2.0.0-beta.1)
  scan: Docker Scan (Docker Inc., v0.8.0)

Docker images

• A Docker image is an immutable file that contains all files an application needs to run properly.

• Docker images represent an application and its virtual environment at a specific point in time

• Docker images are just "templated", they cannot start or run.

• A Docker registry is a storage and distribution system for Docker images.

docker pull public.ecr.aws/bacardi/alpine:3.13.0
docker pull docker.io/library/alpine:3.13.0
docker pull alpine:latest

docker image ls 
docker image rm public.ecr.aws/bacardi/alpine:3.13.0
docker image ls 

Running containers

• A container is a runnable instance of an image

docker run --rm -i -t --name myalpine alpine

Container lifecycles

docker run -d --name alpine 
docker container ls -a

docker run -it --name testalpine alpine

In the container, run:

echo "hello" > world.txt
cat world.txt

Exit the container

check containers

docker container ls -a
docker start container testalpine
docker exec -it testalpine /bin/sh

Check if you can find the file world.txt exit the container and delete the container

docker stop testalpine 
docker rm testalpine

Use --rm to automatically remove exited container

docker run -it --rm -name auto-delete-alpine alpine 

specifying a name

docker run -it --name alpine1 alpine
docker run -it --name alpine1 alpine

Docker persistent storage

Bind mounts

Bind mounts are dependent on the directory structure and OS of the host machine

docker run --rm -it -v /app -v ${PWD}:/myfolder alpine /bin/bash

Docker volumes

volumes are completely managed by Docker.

docker volume create my-vol
docker volume ls
docker volume inspect my-vol
docker run --mount source=myvol,target=/myvolume alpine /bin/bash
docker volume rm my-vol

Environment variable

docker run -it --rm -e NAME=nordine alpine 

Port forwarding

Without port forwarding, we can't reach the container

docker run -it --rm -d --name hello gcr.io/google-samples/hello-app:1.0 
curl localhost:8080

The first parameter is the port on the host and the second is the port on the container

docker run -it --rm -d -p 33333:8080 gcr.io/google-samples/hello-app:1.0 
curl localhost:33333

Manual Wordpress deployment

Run mysql in a container

# create a volume to persist data
docker volume create db_data

# run the container
docker run -d --rm --name mysql -v db_data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=somewordpress -e MYSQL_DATABASE=wordpress -e MYSQL_USER=wordpress -e MYSQL_PASSWORD=wordpress mysql:5.7 

#check the logs
docker logs mysql

wordpress

# create a volume to persist data
docker volume create wordpress_data

# run the container
docker run -d --rm --name wordpress --link mysql:db -p 8000:80 -v wordpress_data:/var/www/html -e WORDPRESS_DB_HOST=db:3306 -e WORDPRESS_DB_USER=wordpress -e WORDPRESS_DB_PASSWORD=wordpress -e WORDPRESS_DB_NAME=wordpress wordpress:latest

#check the logs
docker logs wordpress

Open Wordpress

open localhost:8000

Now delete all containers

Wordpress deployment with Docker compose

Starting the deployment

cd docker-compose
docker-compose up

Tear down

docker-compose down 

Dockerfile

cd dockerfile

Build an image and tag it

docker build -t myalpine .

Create a container from the image

docker run -it --rm myalpine

Change command line parameters

docker run -it --rm --entrypoint /bin/sh  myalpine 

Change entrypoint

docker run -it --rm --entrypoint /bin/sh  myalpine

Push images to docker registries

Run a registry locally

docker run -d -p 5000:5000 --restart=always --name registry registry:2

Retag the previous image

docker tag myalpine localhost:5000/myremotealpine

Push

docker push localhost:5000/myremotealpine

Pull

docker pull localhost:5000/myremotealpine