ulomau / SCA-Cloud-School-Application

SCA-Cloud-School-Application

Exercise done: Exercise 1

Goal: To containerize a Node.js web application into a Docker container

Pre-requisites:

• Working Docker installation, See installation guide here,
• Basic understandinng of docker operations,
• Basic understanding of how a Node.js application is structured.

Application

This is a simple node app for a webpage to display the required contents of SCA Cloud School Application - Welcome to SCA Cloud School Application and Welcome to SCA Cloud School Application, this is my first assessment

Application Setup

1. Run npm init and fill in the details as required;
2. Run npm install to download application packages;
3. Run node app.js to start the server locally on port 2500 or nodemon app.js;
4. Navigate to your browser, visit localhost:2500 and view the content of the index file.

Note: The content viewed depends on the stage/branch of development.

Docker Container

Container 1

The docker container was built using both application and Dockerfile in a folder called docker with a subdirectory, app containing the app.js and other dependencies including the views folder for rendering the webpage.

1. Dockerfile was created using the base image as node:14 with a special directory for the containers and the app dependencies transferred as shown below:

FROM node:14

RUN mkdir p ~/server1

WORKDIR /server1

COPY ./app/package*.json /server1/

RUN npm install

COPY ./app /server1

EXPOSE 2500

CMD [ "node", "/server1/app.js" ]

2. In the docker folder, run docker build -t sca-cloud-image:1.0 . to create the container 1 image Output on successful creation:

Successfully built 404fd66e3f8c
Successfully tagged sca-cloud-image:1.0

3. To create container 1, run docker run -p 1000:2500 --name sca-container-1 sca-cloud-image:1.0. This will create a container named sca-container-1 from sca-cloud-image:1.0 having a host port 1000 mapped to the application port 2500. Output:

Listening on 2500 for first container operation
Welcome to SCA Cloud School Application

4. Navigate to your browse, visit localhost:1000 and view the content of the index file. Output:

Welcome to SCA Cloud School Application

Container 2

1. The required changes were made to container 1 to add addition texts.

2. The Dockerfile was modified to:

FROM node:14

RUN mkdir p ~/server2

WORKDIR /server2

COPY ./app/package*.json /server2/

RUN npm install

COPY ./app /server2

EXPOSE 2500

CMD [ "node", "/server2/app.js" ]

3. In the docker folder, run docker build -t sca-cloud-image:2.0 . to create the container 2 image Output on successful creation:

Successfully built 7fea203a8826
Successfully tagged sca-cloud-image:2.0

3. To create container 2, run docker run -p 2000:2500 --name sca-container-2 sca-cloud-image:2.0. This will create a container named sca-container-2 from sca-cloud-image:2.0 having a host port 2000 mapped to the application port 2500. Output:

Listening on 2500 for second container operation
Welcome to SCA Cloud School Application, this is my first assessment

4. Navigate to your browser, visit localhost:2000 and view the content of the index file. Output:

Welcome to SCA Cloud School Application, this is my first assessment

Image pushed to Docker Hub - Uloma Final Docker Image