docker-course

# select the base image to run the app. We want to run a javascript app, so we use the node runtime image from docker hub
# we can use any image from docker hub. We can also use a custom image that we have created
# node:20-alpine -> node is the image name, 20-alpine is the tag
# alpine is a lightweight version of linux
# we can see complete list of node image tags here: https://hub.docker.com/_/node
FROM node:20-alpine

# set the working directory to /app. This is the directory where the commands will be run. We can use any directory name but /app is a standard convention
WORKDIR /app

# copy everything from the current directory to the PWD (Present Working Directory) inside the container. 
# First `.` is the path to the current directory on the host machine. Second `.` is the path to the current directory inside the container i.e., source and destination
# source - current directory on the host machine
# destination - current directory inside the container (/app)
COPY . .

# commands to run the app
CMD node hello.js

# build the image
# docker build -t hello-docker .
    # -t -> tag the image with a name
    # hello-docker -> name of the image
    # . -> path to the Dockerfile

# set the base image to create the image for react app
FROM node:20-alpine

# create a user with permissions to run the app
# -S -> create a system user
# -G -> add the user to a group
# This is done to avoid running the app as root
# If the app is run as root, any vulnerability in the app can be exploited to gain access to the host system
# It's a good practice to run the app as a non-root user
RUN addgroup app && adduser -S -G app app

# set the user to run the app
USER app

# set the working directory to /app
WORKDIR /app

# copy package.json and package-lock.json to the working directory
# This is done before copying the rest of the files to take advantage of Docker’s cache
# If the package.json and package-lock.json files haven’t changed, Docker will use the cached dependencies
COPY package*.json ./

# sometimes the ownership of the files in the working directory is changed to root
# and thus the app can't access the files and throws an error -> EACCES: permission denied
# to avoid this, change the ownership of the files to the root user
USER root

# change the ownership of the /app directory to the app user
# chown -R <user>:<group> <directory>
# chown command changes the user and/or group ownership of for given file.
RUN chown -R app:app .

# change the user back to the app user
USER app

# install dependencies
RUN npm install

# copy the rest of the files to the working directory
COPY . .

# expose port 5173 to tell Docker that the container listens on the specified network ports at runtime
EXPOSE 5173

# command to run the app
CMD npm run dev

# set the base image to create the image for react app
FROM node:20-alpine

# create a user with permissions to run the app
# -S -> create a system user
# -G -> add the user to a group
# This is done to avoid running the app as root
# If the app is run as root, any vulnerability in the app can be exploited to gain access to the host system
# It's a good practice to run the app as a non-root user
RUN addgroup app && adduser -S -G app app

# set the user to run the app
USER app

# set the working directory to /app
WORKDIR /app

# copy package.json and package-lock.json to the working directory
# This is done before copying the rest of the files to take advantage of Docker’s cache
# If the package.json and package-lock.json files haven’t changed, Docker will use the cached dependencies
COPY package*.json ./

# sometimes the ownership of the files in the working directory is changed to root
# and thus the app can't access the files and throws an error -> EACCES: permission denied
# to avoid this, change the ownership of the files to the root user
USER root

# change the ownership of the /app directory to the app user
# chown -R <user>:<group> <directory>
# chown command changes the user and/or group ownership of for given file.
RUN chown -R app:app .

# change the user back to the app user
USER app

# install dependencies
RUN npm install

# copy the rest of the files to the working directory
COPY . .

# expose port 5173 to tell Docker that the container listens on the specified network ports at runtime
EXPOSE 5173

# command to run the app
CMD npm run dev

# define the services/containers to be run
services:
  # define the application container/service
  # we can use any name for the service. Here it is `web`
  # we can create multiple services as well
  web:
    # specify the image to build the container from
    # this can be any image available in docker hub or a custom one or the one we want to build
    build:
      # specify the path to the Dockerfile
      context: .
      # specify the file name (optional)
      dockerfile: Dockerfile
    
    # specify the port mapping from host to the container
    # this is similar to the -p flag in `docker run` command
    # first port is the port on host machine and the second is the port inside the container
    ports:
      - 5173:5173

    # specify the volumes to mount
    # what this does is it mounts the current directory to the `/app` directory inside the container. 
    # due to this, any changes made to the files in the current directory will be reflected inside the container. It is similar to the -v flag in `docker run` command. 
    # even if a container is stopped or deleted, volumes are not deleted and can be used by other containers as well.
    volumes:
      # over here, we are mounting the current directory to the `/app` directory inside the container (which is the working directory of the container)
      # syntax is `<path to the directory on host>:<path to the directory inside the container>`
      # we're doing this because we want to reflect the changes made to the files in the current directory inside the container
      - .:/app
      # we also mount the node_modules directory inside the container at /app/node_modules. This is done to avoid installing the node_modules inside the container. 
      # node_modules will be installed on the host machine and mounted inside the container
      - /app/node_modules

FROM node:20-alpine3.18

# RUN addgroup app && adduser -S -G app app

# USER app

WORKDIR /app

COPY package*.json ./

# USER root

# RUN chown -R app:app .

# USER app

RUN npm install

COPY . .

EXPOSE 5173

CMD npm run dev

FROM node:20-alpine3.18

RUN addgroup app && adduser -S -G app app

USER app

WORKDIR /app

COPY package*.json ./

# change ownership of the /app directory to the app user
USER root

# change ownership of the /app directory to the app user
# chown -R <user>:<group> <directory>
# chown command changes the user and/or group ownership of for given file.
RUN chown -R app:app .

# change the user back to the app user
USER app

RUN npm install

COPY . . 

EXPOSE 8000 

CMD npm start

# specify the version of docker-compose
version: "3.8"

# define the services/containers to be run
services:
  # define the frontend service
  # we can use any name for the service. A standard naming convention is to use "web" for the frontend
  web:
    # we use depends_on to specify that service depends on another service
    # in this case, we specify that the web depends on the api service
    # this means that the api service will be started before the web service
    depends_on: 
      - api
    # specify the build context for the web service
    # this is the directory where the Dockerfile for the web service is located
    build: ./frontend
    # specify the ports to expose for the web service
    # the first number is the port on the host machine
    # the second number is the port inside the container
    ports:
      - 5173:5173
    # specify the environment variables for the web service
    # these environment variables will be available inside the container
    environment:
      VITE_API_URL: http://localhost:8000

    # this is for docker compose watch mode
    # anything mentioned under develop will be watched for changes by docker compose watch and it will perform the action mentioned
    develop:
      # we specify the files to watch for changes
      watch:
        # it'll watch for changes in package.json and package-lock.json and rebuild the container if there are any changes
        - path: ./frontend/package.json
          action: rebuild
        - path: ./frontend/package-lock.json
          action: rebuild
        # it'll watch for changes in the frontend directory and sync the changes with the container real time
        - path: ./frontend
          target: /app
          action: sync

  # define the api service/container
  api: 
    # api service depends on the db service so the db service will be started before the