Basic Docker Commands 2024

Here are some essential Docker commands, along with examples and explanations for each:

1. docker --version

Description: Displays the Docker version installed on the system.
Example:
```
 docker --version
```
Output:
```
 Docker version 20.10.7, build f0df350
```
Explanation: Helps verify if Docker is installed and check the version for compatibility with specific features or projects.

2. docker pull

Description: Downloads a Docker image from a remote registry (Docker Hub by default) to your local system.
Example:
```
 docker pull nginx
```
Explanation: Downloads the official NGINX image to your local machine. Docker will fetch the image from Docker Hub if it is not available locally.

3. docker images

Description: Lists all the Docker images available locally.
Example:
```
 docker images
```

Output:

 REPOSITORY  TAG     IMAGE ID      CREATED      SIZE
 nginx       latest  ae2feff98a0c  2 weeks ago  133MB

Explanation: Shows all downloaded or built images with details such as repository, tag, image ID, creation date, and size.

4. docker run

Description: Runs a container from an image. It creates, starts, and runs the container from a specified image.
Example:
```
 docker run -d -p 8080:80 nginx
```
Explanation:
- -d: Runs the container in detached mode (in the background).
- -p 8080:80: Maps the container's port 80 to the host machine's port 8080.
- This command will run an NGINX container and serve it on your local machine at localhost:8080.

5. docker ps

Description: Lists all running containers.
Example:
```
 docker ps
```

Output:

 CONTAINER ID  IMAGE   COMMAND       CREATED     STATUS     PORTS                    NAMES
 87dfb6cf56d2  nginx   "/docker-e..."  5 minutes  Up 5 mins  0.0.0.0:8080->80/tcp     amazing_elion

Explanation: Displays all active containers along with information like container ID, image used, running status, and mapped ports.

6. docker stop

Description: Stops a running container.
Example:
```
 docker stop 87dfb6cf56d2
```
Explanation: Stops the container with the ID 87dfb6cf56d2. You can also use the container name instead of the ID.

7. docker rm

Description: Removes a stopped container.
Example:
```
 docker rm 87dfb6cf56d2
```
Explanation: Removes the container from the Docker system. The container must be stopped first. You can use the container ID or name.

8. docker rmi

Description: Removes a Docker image from your local system.
Example:
```
 docker rmi nginx
```
Explanation: Deletes the image nginx from the local machine. If any containers are using this image, you must stop and remove them first.

9. docker exec

Description: Runs a command inside a running container.

Example:

 docker exec -it 87dfb6cf56d2 /bin/bash

Explanation: Opens an interactive shell (/bin/bash) inside the running container. The -it option makes the session interactive, allowing you to execute commands within the container.

10. docker logs

Description: Displays the logs from a running or stopped container.
Example:
```
 docker logs 87dfb6cf56d2
```
Explanation: Fetches the logs for the container with the specified ID, showing output generated by the application running inside the container.

11. docker build

Description: Builds an image from a Dockerfile.
Example:
```
 docker build -t myapp .
```
Explanation: The -t flag assigns a tag (myapp) to the image. The . specifies the build context (usually the current directory where the Dockerfile is located).

12. docker inspect

Description: Returns detailed information about a container or image.
Example:
```
 docker inspect 87dfb6cf56d2
```
Explanation: Outputs a JSON object containing low-level details about the specified container or image, such as network settings, mounts, and configuration.

13. docker-compose up

Description: Starts containers as defined in a docker-compose.yml file.
Example:
```
 docker-compose up
```
Explanation: Spins up all services defined in the docker-compose.yml file, creating containers, networks, and volumes as needed.

14. docker-compose down

Description: Stops and removes containers, networks, and volumes created by docker-compose up.
Example:
```
 docker-compose down
```
Explanation: Cleans up resources used by the docker-compose setup, effectively bringing down the application stack.

Summary of Basic Docker Commands

These commands provide a foundation for working with Docker, covering common tasks such as managing images, containers, networks, logs, and executing commands.