A Quick Introduction to Docker for Absolute Beginners
Tags: docker, devops, webdev, microservices
Published: 2023-10-09 11:46:21


Are you new to containerization and wondering what all the buzz is about Docker? You're in the right place! Docker simplifies the process of developing, deploying, and managing applications. We'll introduce Docker for absolute beginners in this blog post.

**What is Docker?**
Docker is an open-source platform designed to make it easier to develop, deploy, and run applications using containers. Containers are lightweight, portable, and self-sufficient units that package an application and its dependencies, ensuring consistency and reproducibility across different environments.
**Why Use Docker?**
Some of the key benefits of using Docker:
1. Isolation: Containers isolate applications and their dependencies from the underlying system, averting conflicts and ensuring consistency.
2. Portability: Docker containers can run on any system that supports Docker, making it easy to move applications between different environments.
3. Scalability: Docker makes it simple to scale applications horizontally by running multiple containers, improving performance and reliability.
**
Getting Started with Docker**

To begin your Docker journey, follow these simple steps:
1.** Installation**: Start by installing Docker on your machine. You can find installation instructions for various platforms on the [Docker website](https://docs.docker.com/get-docker/). 
`For Mac and Windows, you should download the Docker Desktop onto your laptop.`

2**. Docker Hub**: Docker Hub is a repository of pre-built container images that you can use to get started quickly. You can search for popular images or even publish your own.

**Your First Docker Container**

Once Docker is installed, open a terminal and run the following command to pull and run the "nginx" container:
 ```bash
 docker run nginx
 ```
 This command will download the "nginx" image and run a container from it. 

Here are some useful Docker commands you should know:

1. **`docker ps`**: This command lists all the running containers on your system. By default, it shows the container ID, image name, status, ports, and more.

   ```bash
   docker ps
   ```

2. **`docker ps -a`**: To view all containers, including stopped ones, you can use the `-a` flag.

   ```bash
   docker ps -a
   ```

3. **`docker images`**: This command lists all the Docker images you've pulled or created on your machine.

   ```bash
   docker images
   ```

4. **`docker pull`**: Use this command to download a Docker image from Docker Hub or another container registry.

   ```bash
   docker pull image_name
   ```

5. **`docker run`**: To start a new container, you can use the `docker run` command. 

   ```bash
   docker run  nginx
   ```

6. **`docker stop`**: This command stops a running container by specifying its container ID or name.

   ```bash
   docker stop container_id_or_name
   ```

7. **`docker start`**: To restart a stopped container, you can use the `docker start` command.

   ```bash
   docker start container_id_or_name
   ```

8. **` Docker restart`**: This command stops and then starts a container, which can be useful for applying configuration changes.

   ```bash
   docker restart container_id_or_name
   ```

9. **`docker rm`**: To remove a stopped container, you can use the `docker rm` command. Be cautious, as this action is irreversible.

   ```bash
   docker rm container_id_or_name
   ```

10. **`docker rmi`**: To remove a Docker image from your local machine, use the `docker rmi` command. Make sure no containers are currently using the image you want to remove.

    ```bash
    docker rmi image_name_or_id
    ```

11. **`docker exec`**: You can use this command to run a command inside a running container. This is useful for debugging or executing specific tasks within a container.

    ```bash
    docker exec -it container_id_or_name command
    ```

12. **`docker logs`**: To view the logs of a running container, use the `docker logs` command.

    ```bash
    docker logs container_id_or_name
    ```

**Learning Resources**: You can learn more about Docker by exploring the many tutorials, documents, and online courses that are accessible. Websites like the official Docker documentation and tools like [Play with Docker](https://www.docker.com/play-with-docker) are both excellent sources of information.
Aside from what we've covered here, keep in mind that Docker is a big ecosystem with many other features and possibilities. These fundamentals provide you with a strong starting point for your exploration and experimentation with Docker containers as a complete novice. Good luck containerizing!