docker info gives info

Let's create our first nginx container

docker container run -it -p 80:80 nginx

• -it stands for interactive
• -p stands for publish
• 80 is default nginx port
• nginx — image name

Second 80 is always 80 for nginx and apache, for MySQL, for example, it would be 3306

Now, as it can't find nginx locally, it would download it from DockerHub by itself.

That's it! now localhost:80 is running!

You can get your hands on the hub and look for images there.

Searching for nginx we may find a Dockerfile there.

So what we did in the Starting was simply pulling Dockerfile with nginx instructions and executing it in the image.

• docker container ls would show currently running containers, however, with flag -a would show all containers in the system.
• docker container rm @first 3 symbols of ID@ would erase container
• docker images even if we deleted nginx container, image is still in our system, docker images would show that
• docker pull @REPO@ would download image manually from hub

docker container run -d -p 8080:80 --name mynginx nginx

-d stands for detached, would run in the background

docker ps === docker container ls

Then, let's create an Apache container

docker container run -d -p 8081:80 --name myapache httpd

And MySQL

docker container run -d -p 3306:3306 --name mysql --env MYSQL_ROOT_PASSWORD=123456 mysql

docker container stop would cease process of the container without deleting.

To delete running container we should force it via flag -f.

In order to change files in the container we should open it via bash

docker container exec -it mynginx bash

Here, moving to usr/share/nginx/html we can find our index.html

Well, we don't need to edit it inside bash, that would be madness.

For now, let's remove all containers: docker rm $(docker ps -aq) -f

docker container run -d -p 8080:80 -v $(pwd):/usr/share/nginx/html --name nginx-site nginx

What we did by that is we binded local current folder to /nginx/html folder of the image. Now we can do stuff in that local folder and it would be sent to the container.

Saving index.html in that directory would overwrite container's one and voila!

In order to create image from that application we need to create Dockerfile:

FROM nginx:latest

WORKDIR /usr/share/nginx/html

COPY . .

Now do

docker image build -t divando/nginx-site .

after t divando is DockerHub username and nginx-site is name of the container . is important, it tells where the Dockerfile is.

In order to build such images we don't actually need to create what we did before. Now lets junk it out.

It's time to run our image:

docker container run -d -p 8082:80 divando/nginx-site

And let's push it to our DockerHub!

docker push divando/nginx-site

We download mongo + node app from prepared repo.

In the root let's create Dockerfile:

FROM node:10

WORKDIR /usr/src/app

COPY package*.json ./

RUN npm install

COPY . .

EXPOSE 3000

CMD ["npm","start"]

That should work! Now, Mongo is still lacking here and we probably should create another container for db. In order to connect those we use docker-compose.yml . Create that!

version: '3'
services:
  app:
    container_name:  docker_node_mongo
    restart: always
    build: .
    ports:
      - '80:3000'
    links:
      - mongo
  mongo:
    container_name: mongo
    image: mongo
    ports:
      - '27017:27017'

• restart: always means it would restart every time on fail
• build: . means it would be built by the Dockerfile in this directory
• links: connects containers
• image: mongo as mongo doesn't have a Dockerfile, we have to show, which image it should use, mongo will be pulled from DockerHub

Last would be .dockerignore

node_modules
npm-debug.log 

Than let's build!

docker-compose up

If all set, you can deconstruct the image

docker-compose down

Let's upload that to a droplet!

There are many ways to do that. However, let's do that using Github. Make a repo with our project and push it.

Now create a droplet, git clone into home our repo and just do docker-compose-up

Insight: to delete all images you can use `docker rmi $(docker images -q)`

That's it!