Docker-microservice-multicontainer

In this repository contains main application that communicate with microservice that was exposed via RESTful api.

Main application was developed using single simple page that develop using PHP language, meanwhile the Microservice was developed using Python language running on top of Flask Microservice Framework and flask-restful package as API representation.

Both applications live in its own docker-container.

Requirement

Docker installed on your machine(Docker version 17.09.1-ce, build 19e2cf6 for mac).

Final Folder Structure

|- ~/projects/docker-microservice-container
   |- product #-----> Microservice
     |- api.py
     |- Dockerfile
     |- requirements.txt
   |- website #-----> Main application
     |- index.php
   |- docker-compose.yml

Installation

Create one root project folder with name docker-microservice-container that holds our projects(anywhere) like above structure. These folder contains:

1. products folder

This is where our API resource lived in. It just a simple microservice that was built using python language running on top of Flask Microservice Framework and finally exposed via http protocol.

2. website folder

Our main application lived in here with a simple HTML markup mixed with PHP language.

3. docker-composer.yml file

Contains set of instruction to instruct docker to create docker container,images, etc. We're using this file instead of using docker client command like docker run, docker build,etc.. which is more easy to maintain.

1.1 Product Folder

As mentioned above, this folder contains our API resource and having 3 files to get started:

api.py file

This file contain our python code to expose REST api to the main container.

from flask import Flask
from flask_restful import Resource, Api

app = Flask(__name__)
api = Api(app)

class Product(Resource):
   def get(self):
      return {
         'products': [
            'proton', 'perodua', 'toyota'
         ]
      }

api.add_resource(Product, '/')

if __name__ == '__main__':
   app.run(host='0.0.0.0', port=80, debug=True)

Dockerfile file

Sets of instruction to pull image from docker hub and copy our source code into target destination.

 FROM python:3-onbuild      # pull image from docker-hub    
 COPY . /usr/src/app        # copy source code into target destination   
 CMD ["python", "api.py"]   # command to run microservice

requirements.txt file

Contains name of the pyhton packages to install along with the docker image.
```
 Flask==0.12
 flask-restful==0.3.5
```

2.1 Website Folder

This folder only contain simple php code to pull/fetch data from microservice that reside on another container.

index.php

<html>
    <head>
        <title>Main Website</title>
    </head>
    <h1>List of products</h1>
    <ul>
        <?php
            $products = file_get_contents('http://product-service');
            // product-service is a name of services for another container.
            $json = json_decode($products);

            $products = $json->products;

            foreach ($products as $product) {
                echo "<li>$product</li>";
            }
        ?>
    </ul>
</html>

3.1 docker-composer file

This file is the main entry to begin with which contains set of instruction to instruct docker to build an image, container, etc.

version: '3'

services:
    product-service: # microservice container
        build: ./product # folder to looks for dockerfile
        volumes: # This will make our code reflect to the changes that was made inside text editor.
            - ./product:/usr/src/app
        ports: # exposed 5001 port for host machine and 80 for container.
            - 5001:80

    website:
        image: php:apache # Get image from docker-hub
        volumes:
            - ./website:/var/www/html
        ports:
            - 5000:80
        depends_on: # This container depends on product-service container
            - product-service

Run

Open terminal and navigate to root project directory and run docker-compose -d up .

-d will make the process running on background.

If everything goes well, you should be able to run main application inside web browser using http://localhost:5000.

Extras

List of running docker-containers

docker ps. Run docker ps -a to list containers(include not running containers)
List of docker-images

docker images
Remove image

docker rmi <image-id> <image-id> ....
Remove container

docker rm <container-id> <container-id>

p/s: Self noted references :)

Best Flask open-source libraries and packages

Docker microservice multicontainer