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Dockers: Here’s What You Need to Know

May 11, 2023
Written by
Joshua Jebaraj

Imagine you're a sailor, and you're transporting goods across the ocean. If you're thinking of loading into one ship, then what are you gonna do if something goes wrong? Think about pirates, or what if the ship sinks? You'd lose everything!

That's where Docker comes in! Instead of having one big ship, Docker is like having a fleet of small and freestanding ships individually hauling a small number of goods. Even if one of them sinks, the others will still have a chance of getting to their destination. But these ships aren't your usual ships — they're extremely fast and efficient. Plus, they can fit into any port. How can they do it? Well, every ship has its own dedicated captain and crew who knows exactly how to navigate them. They don't even need anything — all they'll need to complete their voyage is on board already.

Now let’s get serious (or not)!

Table of Contents

  1. Let’s talk about Dockers
  2. Docker Security — why is it so relevant?
  3. Who uses Docker?
  4. Docker Terminologies that you should know
  5. Container Security: The Ultimate Showdown Between Devs and Hackers


Let’s talk about Dockers

Docker is a platform for building, shipping, and running applications using containerization. It lets developers package their applications and dependencies into small and portable containers that can run on any machine, regardless of the underlying operating system. Each of these containers is isolated from the host system and other containers to provide a secure and consistent environment for the application to run in. And because containers are lightweight and share resources with the host system, they're super-efficient and can be spun up and torn down in seconds.

But Docker isn't just for that - it's also an amazing tool for development and testing. Through Docker, you can easily set up and tear down environments depending on applications, test out various configurations, and experiment without worrying about messing up your entire host system.

Docker Security — why is it so relevant?

While the idea of containerization has existed for decades, the introduction of Docker in 2023 made it more attractive for organizations to integrate a container-first development model. However, with this progress comes the necessity of a robust security initiative to safeguard applications from threats. Here are a few reasons why container security is essential:

  1. Isolation - Container isolation provides an extra blanket of protection by using a variety of methods to harden container isolation without affecting the works of developers. This can make all the difference in stopping the reach of malware or other security threats. 
  2. Vulnerability Scanning - Containers can detect vulnerabilities within an environment, including configuration issues, outdated software, and software dependencies.
  3. Automation - Automation tools like Kubernetes, where containers are usually deployed, make sure that security policies and configurations are automated too.
  4. Compliance - Organizations have certain compliance requirements to meet, and one of them is container security.
  5. Cloud-native applications - Cloud-native applications lean heavily on container security to ensure the overall security of applications running within them.

Who uses Docker?

Docker provides consistency, portability, scalability, and more with modern application development and deployment. Because of that, it is being used by a lot of individuals and organizations for building, packing, and running applications. Here are some examples of who use Dockers:

  1. Developers - Docker is being used by developers to create a consistent and reproducible development environment for a much easier way to share data with team members.
  2. DevOps teams - To automate the deployment of applications and services, DevOps use Docker to make managing infrastructure and reducing downtime more straightforward.
  3. IT operations teams - IT operations teams use Docker to manage and scale their infrastructure to reduce the time and effort required in managing servers.
  4. Startups and small businesses - For startups and small businesses, the main selling point of Docker is its ability to diminish the cost and make manipulating infrastructure much simpler.
  5. Enterprises - Big companies use Docker to modernize their current applications and infrastructure, so they can migrate to the cloud and adopt new technologies without breaking a sweat.
  6. Cloud providers - Cloud providers offer Docker as a service to provide their customers with an easier way to deploy and manage their applications on the cloud.

Docker Terminologies that you should know

Are you one of these? If so, then why don’t we check your knowledge with Docker?

You might have heard of “Docker” before and might even be using it right now. Truth be told, terms like Kubernetes, containerization, and Kernels can be daunting and complicated to wrap your mind with. But as someone who wants to use it and might be using it already, you have to know the basic terminologies used with Dockers. Let’s start!


Dockerfile is simply a text file that can define Docker images automatically. It is a lightweight, standalone, executable package with all the necessary tools to run an application. Dockerfile makes it easier to create and configure Docker images repeatedly.

Docker Images

Docker images (sometimes called snapshots) perform as the building blocks of Docker containers. It is a read-only template with a set of instructions for creating Docker containers. It also shows its user where to look for ready-made-off-the-shelf images that they will need to run an application.


Containers help in solving the problem of getting the software to run more consistently when deployed from one machine to another or from one environment to another. It does that by packaging code, its dependencies, and libraries.

Docker Repository

A Docker repository is used for storing and distributing Docker images. It can also be used for creating much quicker CI/CD pipelines. Users have the option to host a Docker repository on a public or private registry.

Docker Volume

Docker volumes are a mechanism for creating persistent data storage for Docker containers. If a container is destroyed, like when the server crashes or has security issues, all the files created within that container will be lost, but Docker volumes have a way to persist data beyond the lifecycle of a container.

Docker Compose

A Docker repository is used for storing and distributing Docker images. It can also be used for creating much quicker CI/CD pipelines. Users have the option to host a Docker repository on a public or private registry.

Docker Hub

Docker Hub is a registry service based on the cloud that lets developers store and shares Docker images while providing a central repository that can be used to share and collaborate on container images. Docker Hub also serves as the main spot where the members of the container community meet and collaborate.

Docker Daemon

Docker Daemon or dockerd is a process that runs in the background of the host machine that manages Docker containers, images, volumes, networks, and other Docker objects. It persists all this data in a single directory.


Orchestration is simply the procedure of automating the deployment, management, and scaling of containerized applications at a large scale. Some examples are Kubernetes, Docker Swarm, and Red Hat’s OpenShift.

Container Security: The Ultimate Showdown Between Devs and Hackers

In the wild world of DevOps, containerization has become the weapon of choice in streamlining application development. It delivers exceptional agility, scalability, and portability, entitling developers to deploy code faster than a speeding bullet. But securing containerized applications can feel like a battle against a never-ending stream of cyber threats.

You can't fight this battle alone. AppSecEngineer is here to offer you our wide arsenal of tools, resources, and experience to ensure that you have what it takes to build an impenetrable fortress of container security. Here are some samples of our weapon of choice:

  1. Container Security Learning Path
  1. Kubernetes Security Learning Path

With the right mindset, skills, and tools, you can emerge victorious. So embrace the challenge, become a container security warrior, and help shape the future of DevOps.

Source for article
Joshua Jebaraj

Joshua Jebaraj

Joshua Jebaraj is the Creator of GCP-Goat. He works as Security Researcher at we45 focusing on cloud and cloud-native security. He has 3+ years of experience working related to containers and Kubernetes. He has also spoken at conferences like Defcon, Owasp-Seasides, Bsides-Delhi, and Eko-party. When AFK, he can be found watching movies and making memes.

Joshua Jebaraj


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