Docker lab

In this lab, we going to run a Books service app. Books service app consists of web (ExpressJS) and database (MongoDB) services.

Prerequisite

Install docker.

sudo yum update -y
sudo amazon-linux-extras install docker
sudo service docker start
sudo usermod -a -G docker ec2-user

After installing docker, closing the current SSH session and reconnecting.

Install docker-compose

sudo curl -L "https://github.com/docker/compose/releases/download/1.28.5/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

sudo chmod +x /usr/local/bin/docker-compose

Install git.
```
sudo yum install git -y
```

Clone the project.

git clone https://github.com/fpiyapol/cie-docker-lab.git

Create Docker file

Change directory to cie-docker-lab.
```
cd cie-docker-lab 
```

Create Dockerfile for a web service with below content.

FROM node:12.21.0-alpine3.12

WORKDIR /usr/src/app

COPY ./web ./

RUN npm install

EXPOSE 8080

CMD [ "node", "main.js" ]

Run following command to build a web service image.
```
docker build -t web .
```
Inspect web image.
```
docker images
```

Run a web service container.

docker run -d --name web -p 8080:8080 web

Inspect web service container.
```
docker ps
```
Test web service by go to <IP address>:8080/books. You should see book information.
```
[
  {
    id: "1",
    name: "alice"
  },
  {
    id: "2",
    name: "bob"
  }
]
```
Please make sure firewall allows connection on port 8080 and the web service container is running.

Run MongoDB Database Service

Issue following command.

docker run -d --name mongodb -p 27017:27017 \
-v $(pwd)/database:/docker-entrypoint-initdb.d bitnami/mongodb:4.2.10-debian-10-r26

Inspect the database.

docker ps
# should see mongodb container running.

docker exec -it mongodb mongo
show dbs
# should see books database

use books
show collections
db.books.find()
# should see books information.

exit

run web service again.

docker rm -f web
docker run -d --name web -p 8080:8080 --link mongodb:mongodb \
-e SERVICE_VERSION=v2 -e 'MONGODB_URL=mongodb://mongodb:27017/books' web

Book service app uses the SERVICE_VERSION variable to toggle version to use an external database.

Test web service. Now you should see new books information.

[
  {
    id: "1",
    name: "Kubernetes in Action"
  },
  {
    id: "2",
    name: "The Phoenix Project"
  }
]

Create Docker-Compose file

Create docker-compose.yml with following content.

version: "3.8"
services:
  web:
    image: web
    ports:
    - "8080:8080"
    environment:
      SERVICE_VERSION: v2
      MONGODB_URL: mongodb://mongodb:27017/books
  mongodb:
    image: bitnami/mongodb:4.2.10-debian-10-r26
    ports:
    - "27017:27017"
    volumes:
    - ./database:/docker-entrypoint-initdb.d

Run docker-compose.

# delete all containers
docker rm -f $(docker ps -aq)

# run docker compose
docker-compose up -d

Test web service.