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Dockerfile

This Dockerfile details instructions for building a Docker image for a Node.js application. Let's analyze each section:

Base Image​

# BASE IMAGE
# Using node:20-bullseye-slim as the base image for our Docker build
FROM node:20-bullseye-slim AS base
  • Base Image: Uses the node:20-bullseye-slim image as a base. This is a lightweight Node.js version 20 image, based on Debian Bullseye Slim.
# Updating package lists and upgrading installed packages
RUN apt-get update -y
RUN apt-get upgrade -y
  • Package Update: Updates the list of packages and then updates the installed packages.
# Installing git as it is commonly used for various build processes
RUN apt-get install -y git
  • Git Installation: Installs Git, commonly needed for build processes.
# Installing a specific version of npm globally
RUN npm i -g npm@latest
  • NPM Installation: Updates npm to the latest version globally.

Build Image​

# BUILD IMAGE
# Creating a new build stage starting from the "base" stage
FROM base AS builder
  • Build Stage: Starts a new build stage based on the "base" stage.
# Setting the working directory inside the Docker container
WORKDIR /codechat
  • Working Directory: Defines /codechat as the working directory in the container.
# Copying specific project files needed for installing dependencies
COPY ./package.json ./tsconfig.json ./
  • Copies Project Files: Copies package.json and tsconfig.json to the container, necessary to install dependencies.
# Installing npm packages defined in package.json
RUN npm install
  • Dependency Installation: Installs the npm dependencies defined in package.json.
# Copying source code, public files, documentation, and Prisma configuration
COPY ./src ./src
COPY ./public ./public
COPY ./docs ./docs
COPY ./prisma ./prisma
COPY ./views ./views
COPY ./.env ./.env
  • Copy of Project Files: Copies the source code, public files, documentation, Prisma configuration and others to the container.
# Copying scripts to working directory.
COPY ./scripts ./scripts
  • Script Copy: This command copies the scripts located in the host's ./scripts directory to the same directory in the container. These scripts are used to configure and manage the database.
# Execution permission
RUN chmod +x ./scripts/*
  • Execute Permission: Modifies the permissions of script files to make them executable. This is necessary so that scripts can be executed inside the container.
# Executing command
RUN ./scripts/run_database_operation_deploy.sh
  • Running Command: Runs the ./scripts/run_database_operation_deploy.sh command defined in npm scripts, which in turn runs the detailed Bash script.

The Bash script performs the following actions:

  1. Environment Configuration:

    • Checks if it is running in a Docker environment. If not, it reads environment variables from a .env file and exports them.

  2. Database URL Verification and Configuration:

    • Checks if the DATABASE_PROVIDER is one of the supported ones (PostgreSQL, MySQL, MongoDB).
    • Builds the DATABASE_URL based on the provided environment variables, adjusting the schema according to the database provider.

  3. Execution of Prisma Commands:

    • Runs prisma migrate deploy to apply database migrations.
    • Runs prisma generate to generate the Prisma client according to the schema.

  4. Error Handling:

    • If the DATABASE_PROVIDER is not one of the expected ones, or if the .env file is not found, the script displays an error message and ends with an error status.

This script is a crucial part of the deployment process, ensuring that the application has the correct environment variables and that the database is correctly configured and migrated before starting the application.

# Running the build process defined in package.json
RUN npm run build
  • Build Process: Executes the build process defined in package.json.

Release Image​

# RELEASE IMAGE
# Creating a new stage for the release image starting from the "base" stage
FROM base AS release
  • Release Stage: Starts a new stage for the release image, using the "base" stage as a base.
# Setting the working directory
WORKDIR /codechat

# Copying package.json and package-lock.json from the "builder" stage
COPY --from=builder /codechat/package.json ./package.json
COPY --from=builder /codechat/package-lock.json ./package-lock.json

# Installing only production dependencies
RUN npm install --omit=dev

# Copying built code and Prisma configuration from the "builder" stage
COPY --from=builder /codechat/dist ./dist
COPY --from=builder /codechat/prisma ./prisma
COPY --from=builder /codechat/public ./public
COPY --from=builder /codechat/docs ./docs
COPY --from=builder /codechat/views ./views
COPY --from=builder /codechat/.env ./.env
COPY --from=builder /codechat/scripts ./scripts

# Creating a directory for instances (purpose may vary depending on the application)
RUN mkdir instances

# Setting environment variables for the Docker container
ENV DOCKER_ENV=true
ENV NODE_ENV='production'
  • Release Stage Configuration: Copies necessary files from the build stage, installs only production dependencies and configures environment variables.
# Command to run when the Docker container starts
ENTRYPOINT ["/bin/bash", "-c", ". ./scripts/run_database_operation_generate.sh && npm run start:prod" ]
  • Startup Command: Defines the npm run start:prod command to be executed when the container starts.

In summary, this Dockerfile creates a Docker image for a Node.js application, using multiple stages to optimize the size of the final image. It starts with a base stage for general configurations, follows with a build stage to build the application, and ends with a release stage to prepare the image for production.