4 min. read

What are Containerized Applications?

Containerized applications, or the idea of isolating environments, isn’t new. However, the evolution of cloud-native applications, the use of microservices, and the needs of DevOps have made containers the de facto standard for most software development.

An IBM survey revealed that 61% of organizations developing containerized applications used containers in 50% or more of their new app development over the previous two years. And, 64% of those surveyed expected that half or more of their existing applications would leverage containers going forward. A second survey by the Cloud Native Computing Foundation found that 93% of participants already use or plan to use containers. Clearly, more software development teams are using containerization to create and manage new applications alongside modernizing their existing applications for the cloud.

What is a Containerized Application?

Containerized applications are a form of virtualization, packaging software code with the minimum files and dependencies required. These “containers” create a self-sufficient software package that can perform consistently no matter their environment. Other characteristics of containerized applications include:

  • Encompass a fully packaged and portable computing environment
  • Include a single executable file called an image
  • Create isolated environments that are abstracted from the host operating system
  • Share the host machine’s operating system kernel rather than require a copy of the host operating system
  • Bundle app code with all dependencies as part of the container – settings, frameworks, system libraries, binaries, configuration files, and security defaults

Most critical to cloud-native application development, containers provide a portable and environment- or infrastructure-agnostic package that can be moved and run consistently on any device, platform, or cloud service. These features make containerization pivotal to modern cloud-based and microservices-dependent application development.

Containerized Applications are Pivotal to Modern, Cloud-Native Software Development

When containerized applications, microservices, and cloud computing are combined, they deliver new levels of agility, efficiency, reliability, and security, which support faster go-to-market cycles.

Traditional software development, before containers, built gigantic programs that relied on intertwined components. Containers have accelerated the adoption of service-oriented architectures like microservices and cloud, as well as the transition to DevOps. But, whether an application is a single-tiered, legacy application, or modular built on microservices, containerization breaks a complex application into smaller, more specialized, and manageable components. Plus, capturing legacy applications in containers and deploying them through a cloud environment helps teams modernize applications without rewriting all code.

Containerized Applications Offer Numerous Benefits

Container technology offers significant benefits, particularly when compared to virtualization and traditional development approaches that work in a specific computing environment. Overall, containerization supports faster and more secure application creation and deployment.

The most oft-mentioned benefit of containerized applications is their portability. A container is encapsulated in a single, executable package that isn’t tied to or dependent upon the host operating system. It can run uniformly and consistently across any platform, device, or cloud service. Other container benefits are critical to its adoption:

  • Containers are much smaller than with virtual machines (VM), faster to boot, and more efficient
  • Reduced cost due to fewer server or licensing costs and because a full guest OS or hypervisor is not required
  • Easily transportable among environments – desktop to virtual machine, Linux to Windows OS, cloud-to-cloud
  • Microservices within containers can be repaired, redeployed, and scaled more quickly
  • Reduced cyber risk to a host system or other containers if malicious code is present in one container
  • Fault isolation is possible because each container operates independently of others

The benefits make containerized applications a lightweight and “write once and deploy anywhere” software approach that fits the needs of cloud-enabled DevOps teams.

Containerized Applications Need a Runtime Engine and Orchestrator

Two tools, a runtime engine and container orchestration make containerized applications easier to manage and run.

An open-source runtime engine, like Docker or those that meet Open Container Initiative (OCI) standards, acts as a conduit for containers to share an operating system with other containers on the same computing system. A runtime engine enables developers to build, deploy, and test containerized applications across environments.

Container orchestration tools like Kubernetes automatically manage multiple containers that depend on a complex web of microservices and APIs. They enable DevOps teams to automate rollouts, rollbacks, logging, debugging, and carry out load balancing.

What are the Challenges to Accelerating the Adoption of Containerized Applications?

If containerized applications deliver so many benefits, why aren’t 100% of software development teams and organizations using them? There are three main challenges to adoption.

Legacy system stability and investment

Containerizing legacy software is a transformation process. For organizations who have critical software systems that are stable and they’ve invested in for 10 or 20 years, they may think, “If it’s not broken, why fix it?” The transition to containers can pose business and operations risks without clear benefits.

Yet, containerized applications are driving faster SDLCs and nimble market entrants. Companies relying on monolith systems may need to assess the maintenance cost compared to the value of cloud-native development in the face of market disrupters and competition.

Remaining cloud reticence

Many organizations are working through how to navigate cloud and DevOps transformations. Their concerns with cloud technologies and cloud-native development can keep them from embarking on containerized development.

Security considerations for containerized applications

Containerized applications have a default level of security because they use isolated processes and operate independently from other containers. While this offers a level of protection, there are security considerations when transitioning to bimodal or fully containerized development.

Application layers within a container can be shared across containers, creating some security risks. Also, threats to the common OS may impact all related containers. Conversely, container breaches can affect the host OS.

Rather than take a “secure-by-default” stance, teams should ensure that their container engine supports and orchestration tools are configured appropriately. These should include default isolation properties, identity and access management policies, and security permissions.

Containerized, Cloud-Native Security Relies on Panoptica

Cisco’s Emerging Technologies and Incubation (ET&I) team is paving the way with “DevOps-friendly” cloud-native security solutions that fundamentally simplify conventional offerings. Our Panoptica solution simplifies cloud-native application security, making it easy to embed into the software development lifecycle. Panoptica protects the full application stack from code to runtime by scanning for security vulnerabilities in the cloud infrastructure, microservices (Containers or Serverless), the software bill of materials, and the interconnecting APIs. And best of all, it integrates with the tools that your application development and SecOps teams are already using. Try Panoptica for free!