What are some examples of Docker configurations?

What are some examples of Docker configurations?

Docker configurations can vary widely depending on the application. Are you looking for examples for a specific use case?

Yes, I need examples for a web application using Node.js.

For a Node.js web application, you might have a Dockerfile like this:

FROM node:14
WORKDIR /usr/src/app
COPY package*.json ./
RUN npm install
COPY . .
EXPOSE 3000
CMD ["node", "app.js"]

And a simple docker-compose.yml could look like:

version: '3'
services:
  web:
    build: .
    ports:
      - "3000:3000"

Can you explain what each part of the Dockerfile does?

Sure! Here's a breakdown:

• FROM node:14: Specifies the base image to use, in this case, Node.js version 14.
• WORKDIR /usr/src/app: Sets the working directory inside the container.
• COPY package*.json ./: Copies package files to the working directory.
• RUN npm install: Installs the dependencies listed in package.json.
• COPY . .: Copies the rest of the application files.
• EXPOSE 3000: Informs Docker that the container listens on port 3000.
• CMD ["node", "app.js"]: Specifies the command to run the application.

What if I want to add a database to this configuration?

You can extend your docker-compose.yml to include a database service. For example:

version: '3'
services:
  web:
    build: .
    ports:
      - "3000:3000"
  db:
    image: postgres:latest
    environment:
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password
      POSTGRES_DB: mydb