Application Containerization and Security Concerns
Containerization has off-late, become the new buzzword in the DevOps domain, for it has provided a new way of hosting applications. Like Virtualization, Containerization too abstracts the workload on the hardware, but in a different manner. Unlike Virtualization, where each Virtual Machine (VM), replicates a server with a complete Operating System (OS) and resources such as binaries, files and libraries (with VM itself running on a hypervisor), Containerization runs the application on the Host Operating System (HOS), without a hypervisor and holds all the resources required for running application software by accessing a single kernel of the OS.
Implementing Containerization — Docker
A container strategy for applications is implemented using a software tool like Docker, an open source program for developing, shipping, and running applications. Although there are several tools for implementing containerization like VMware vApp, and Chef, Docker continues to be the most popular one. Docker serves as a tooling platform for application development and streamlines the lifecycle by:
- Allowing developers to encapsulate the application source code into Docker Containers
- Providing controlled access to the testers for testing the source code
- Deploying the applications in the production environments—servers or cloud
In Docker, each container is an operable instance of an application; operations such as Start, Stop, Move or Delete can be performed on each container. The library files required for supporting the application are stored in Docker Registries. Docker containers typically run on computers, virtual machines, bare-metal servers and OpenStack cloud clusters.
By containing the source code and the resources such as libraries to run the source code of the application in a single unit, Containerization tends to isolate different applications from each other on a shared OS. The entire arrangement tends to be advantageous in several ways.
Advantages of Containerization
Computation resources such as memory, storage and processor time required to implement containerization, are much lower as compared to the conventional virtualization methods. As containers do not have the overhead of a guest OS unlike VMs, an OS can support a greater number of containers than VMs, which boosts the server utility resources by a factor ranging from 10 to 100. The “light weight” nature of a container (due to the absence of a guest OS and the hypervisor, both of which are present in a VM) the portability of applications is hugely simplified.
The efficient utilization of a single OS enabled by containers saves the cost of procuring licenses for multiple copies of the same OS, for companies. Also, for identical server settings an application container can function on any system or cloud without any code changes.
Challenges Associated with Containerization
While containers show an efficient and cost effective way of hosting applications, they also tend to present certain challenges. The most conspicuous one is the lack of isolation from the HOS. As an application container runs on HOS, a hacker who gets access to a container can breach into the HOS as well as other containers. This is a major concern as any access to the host allows a hacker to function as the root user or the administrator.
Faulty networks lead to cross-container threats, where one container gains unauthorized access to another in the same network due to hacking, could challenge the isolation of application environments. Malicious content present in the libraries and binary files downloaded to run the application containers, could also pose a potential threat to the security of application data.
Addressing the Challenges
Container software providers strive to fortify the software data, as data breaching activities scale new heights. For mitigating the threats to container environments, tools like Docker have built functionalities to ensure that the root user remains separate from the container and HOS environments, which prevents hackers from gaining control over as the root user. Further, a safe repository for downloading the libraries and binary files, called the Docker Hub Repository (DHR), has been created by Docker. DHR subjects all files to cryptographic guarantee to ensure the cleansing of all the known malware. Also, container scanners that scan for breaching activities to issues alerts about the modification of content have been instrumental in mitigating the challenges of cyber threats. Providers of container software today continue to invest on various measures to offer a secure environment to the enterprises.
While container tools themselves offer ways of securing the container environment, adopting and implementing efficient data security programs too goes a long way. Measures like updating the HOS regularly and security patches, would play a crucial role in securing the container environment. Irrespective of the benefits provided by container software, a robust security policy would continue to be relevant for container security.