What is the main goal of using containerization with Docker and what tasks does it help to solve?

The main goal of containerization with Docker is to ensure isolation and portability of applications along with all their dependencies. This allows running the application in the same environment on different machines, avoiding environment compatibility issues.

Tasks solved by Docker:

• Environment isolation: containers run independently of each other and the host.
• Portability: a container can be run on any system with Docker without changes.
• Simplified deployment: automation of building and running applications.
• Scalability: easily create and manage multiple instances of an application.
• Dependency management: all libraries and settings are packaged together with the application.

Example Dockerfile for a Node.js application:

FROM node:18
WORKDIR /app
COPY package*.json ./
RUN npm install
COPY . .
CMD ["node", "index.js"]