Based off of https://www.youtube.com/watch?v=MnDT1aB39hQ

Docker is a flexible wrapper around many types of applications. DBs, web servers, and others. It is supposed to make composing all these easy. And to make running code in N environments easy. It also is more efficient than vms since it doesnt need a whole OS. It just uses the host OS.

• Install docker client and open
• Create docker account and log in on the docker client
• or use docker login to log in

Download an image

docker pull nginx

Or just try to run the image and it will be auto downloaded

docker run -it -p 80:80 nginx

`docker run`    run the server
`-it`           interactive mode or `-d` for detached mode
`-p 80:80`      map internal port 80 to external port 80
                `<localhost port>:<internal docker port>`
`nginx`         the name of the image that we want to run

Verify its running by going to localhost:80. You will see the default Nginx page.

Also verify by running

docker ps # ps stands for "process status"

To also list stopped containers, run

docker ps -a

-d instead of -it for detached mode

docker run -d -p 80:80 nginx

Stop it

docker stop 5d9d4ad88923

Remove it

docker rm 5d9d4ad88923

This wont remove the image. View downloaded images can be seen like so:

docker images

Remove the image

docker image rm e445ab08b2be

docker run -d -p 80:80 --name tutorial-nginx-01 nginx

Then you can stop it with

docker stop tutorial-nginx-01

or restart it with

docker start tutorial-nginx-01

Run bash within the container

docker exec -it tutorial-nginx-01 bash

then you can do stuff in the container

cd /usr/share/nginx/html
cat index.html

We can use "volumes" to connect files from outside the container into the container. We will "mount" the volume on our locally machine into the target folder.

I've made a file called Desktop/docker-volume/index.html on my desktop. We will move it to the container.

docker run -d -p 80:80 -v ~/Desktop/docker-volume/:/usr/share/nginx/html --name tutorial-nginx-01 nginx

Now /Desktop/docker-volume/ is placed in /usr/share/nginx/html

Create a Dockerfile next to the index.html file.

FROM nginx # declare the image to use
COPY html /usr/share/nginx/html # declare the files to copy to the server

The start the container

docker build -t custom-image-1 .

`docker build`                The build command
`-t custom-image-1`    Name the image
`.`                           location of the folder to build a custom image

docker run --name my-nginx -p 80:80 -d custom-image-1

First tag the image

docker tag custom-image-1 YOU_USERNAME/custom-image-1

Push to dockerhub

docker push YOU_USERNAME/custom-image-1

Push a new tag like so

docker push dynamojim/custom-image-1:tagname

Based off of https://www.youtube.com/watch?v=hS-czwYyTpo

You can combine or connect multiple docker images. Say, a db and a web server.

For this we will use docker compose. The example will be a node application with a REST api and a database instance of mongo db as a second service.

A distributed app consists of different pieces The pieces are each call "service" So this is the "service" of "micro-services"

You can run replicas (multiple containers) of one image to scale capacity

To define, we will create a docker-compose.yml file then excecute with the docker-compose command.

The following steps have been included in the repo

1. Set up an express server in JS. (Included in Repo)
2. Set up a Dockerfile for the JS server
3. Set up docker-compose.yml

In the terminal, in the project folder

docker-compose up

In the terminal, in the project folder

docker-compose ps

In the terminal, in the project folder

docker-compose down