Educational Docker Project Documentation

This project is designed for educational purposes to practice working with Docker. It demonstrates how to set up a Node.js application using Docker, and includes a Makefile for easy management of Docker commands. Below is an explanation of each component in the project.

Dockerfile

FROM node
WORKDIR /app
COPY package.json /app
RUN npm install
COPY . .
ENV PORT 4200
EXPOSE $PORT
VOLUME ["/app/data"]
CMD ["node", "main.js"]

The Dockerfile contains the instructions to build a Docker image for the Node.js application. Here is a breakdown of each command:

FROM node

This line specifies the base image for the Docker image. The node image includes Node.js and npm pre-installed.

WORKDIR /app

This command sets the working directory inside the container to /app. All subsequent commands will be run in this directory.

COPY package.json /app

This line copies the package.json file from the host machine to the /app directory in the container. This file contains the dependencies required for the Node.js application.

RUN npm install

This command runs npm install inside the container to install the dependencies listed in the package.json file.

COPY . .

This line copies all files from the current directory on the host machine to the /app directory in the container.

ENV PORT 4200

This command sets an environment variable PORT inside the container to 4200. The application will use this port to listen for incoming requests.

EXPOSE $PORT

This line informs Docker that the container will listen on the specified port (4200). This is used for documentation purposes and doesn't actually publish the port.

VOLUME ["/app/data"]

This command creates a volume at /app/data inside the container. Volumes are used to persist data generated by and used by Docker containers.

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

This command specifies the default command to run when the container starts. It runs the Node.js application by executing node main.js.

.dockerignore

node_modules
.idea
.git
Dockerfile

node_modules: This directory contains local Node.js dependencies and should not be included in the Docker image.

.idea: This directory contains project-specific settings for IDEs and should be excluded.

.git: This directory contains version control data and should be excluded.

Dockerfile: Excluding the Dockerfile itself to prevent it from being copied into the image.

Makefile

create_image:
	docker build -t node_docker:env .
run:
	docker run -d -p 3000:4200 -v logs:/app/data --env-file .env --rm --name node_docker node_docker:env
run_dev:
	docker run -d -p 3000:4200 -v $(shell pwd):/app -v /app/node_modules --env-file .env --rm --name node_docker node_docker:env
run_dev_nodemon:
	docker run -d -p 3000:4200 -v $(shell pwd):/app -v /app/node_modules --env-file .env --rm --name node_docker --entrypoint "npx" node_docker:env nodemon main.js
stop:
	docker stop node_docker

The Makefile defines a set of commands to manage Docker operations. Here is an explanation of each command:

create_image:
	docker build -t node_docker:env .

create_image: This target builds the Docker image with the tag node_docker:env using the Dockerfile in the current directory (.).

run:
	docker run -d -p 3000:4200 -v logs:/app/data --env-file .env --rm --name node_docker node_docker:env

run: This target runs the Docker container in detached mode (-d), mapping port 3000 on the host to port 4200 in the container (-p 3000:4200). It also mounts the logs volume to /app/data inside the container and loads environment variables from the .env file. The container is named node_docker and will be removed automatically when stopped (--rm).

run_dev:
	docker run -d -p 3000:4200 -v $(shell pwd):/app -v /app/node_modules --env-file .env --rm --name node_docker node_docker:env

run_dev: This target runs the Docker container in development mode. It mounts the current directory ($(shell pwd)) to /app inside the container, allowing live editing of files. It also mounts a volume for node_modules to use local dependencies. The rest of the parameters are the same as the run target.

run_dev_nodemon:
	docker run -d -p 3000:4200 -v $(shell pwd):/app -v /app/node_modules --env-file .env --rm --name node_docker --entrypoint "npx" node_docker:env nodemon main.js

run_dev_nodemon: This target runs the Docker container in development mode with nodemon to automatically restart the server on file changes. It overrides the default entry point to use npx nodemon main.js.

stop:
	docker stop node_docker

stop: This target stops the running container named node_docker.

Working with Volumes

Volumes are used to persist data generated by and used by Docker containers. In this project, there are both named and anonymous volumes:

• -v logs:/app/data: This command creates a named volume called logs and mounts it to /app/data in the container. This is useful for persisting log data.
• -v $(shell pwd):/app: This command mounts the current directory on the host machine to /app in the container. This allows for live editing of files during development.
• -v /app/node_modules: This command mounts an anonymous volume for the node_modules directory, preventing local node_modules from being overwritten in the container.

These volumes help in managing data and development workflows efficiently, ensuring that changes are reflected immediately and data is persisted as needed.

This documentation should provide a comprehensive understanding of how the Dockerfile and Makefile work together to manage the Node.js application in both production and development environments.