Remove all stopped containers:

docker container prune

Executing Commands in a Running Container

Execute a command in a running container:

docker exec -it [container_id_or_name] /bin/bash

Viewing Container Logs

View logs of a container:
```
docker logs [container_id_or_name]
```
Follow logs in real-time:
```
docker logs -f [container_id_or_name]
```

Inspecting Containers/Images

Get detailed information about a container or image:
```
docker inspect [id_or_name]
```

4. Dockerfile Instructions

FROM: Base image for the build (e.g., FROM ubuntu:latest). Must be the first instruction.
RUN: Executes commands during image build (e.g., RUN apt-get update && apt-get install -y git).
CMD: Default command to execute when the container starts. Only one CMD per Dockerfile. Can be overridden.
ENTRYPOINT: Configures a container that will run as an executable. Often used with CMD as default arguments.
COPY: Copies files/directories from host to image (e.g., COPY . /app).
ADD: Similar to COPY, but can also extract tar files and fetch remote URLs.
WORKDIR: Sets the working directory for subsequent RUN, CMD, ENTRYPOINT, COPY, ADD instructions.
EXPOSE: Informs Docker that the container listens on the specified network ports at runtime. Does not actually publish the port.
ENV: Sets environment variables (e.g., ENV APP_COLOR=blue).
ARG: Defines build-time variables (e.g., ARG VERSION=1.0).
VOLUME: Creates a mount point for external volumes.
USER: Sets the user name or UID to use when running the image (e.g., USER root).

5. Docker Compose

Define and run multi-container Docker applications.

Basic Commands

Start services defined in docker-compose.yml:
```
docker-compose up
```
Start services in detached mode:
```
docker-compose up -d
```
Stop and remove containers, networks, and volumes:
```
docker-compose down
```
Build or rebuild services:
```
docker-compose build
```
List services:
```
docker-compose ps
```
View logs of services:
```
docker-compose logs
```

Execute a command in a service container:

docker-compose exec [service_name] [command]

`docker-compose.yml` Structure

version: '3.8'
services:
  web:
    build: .
    ports:
      - "5000:5000"
    volumes:
      - .:/code
    environment:
      FLASK_ENV: development
    depends_on:
      - redis
  redis:
    image: "redis:alpine"
networks:
  default:
    driver: bridge

version: Specify Compose file format version.
services: Define application services.
build: Path to the Dockerfile or context.
image: Specify an existing image.
ports: Port mapping (HOST:CONTAINER).
volumes: Volume mapping (HOST:CONTAINER).
environment: Environment variables for the service.
depends_on: Define service dependencies (does not wait for service to be "ready").
networks: Define custom networks.

6. V