With the rising demand for the cloud, so does the usage of containers to deploy applications. According to the 2020 State of the Cloud Report by Flexera, 61% of IT employees prefer to use or experiment with Containers as a Service technology. With the advent of containers, developers are ready to explore new ways of deploying apps, fixing various scaling issues that traditionally exist.
Before we explore more about the best containerization tools, let’s have a quick recap on what containers are.
What Are Containers?
Containerization is a virtualization technique that a developer uses for deploying and running applications. With the advent of containers, there is no need to launch an entire virtual machine (VM) for each app as they run on a single host and access the same OS kernel.
Containerization is now a leading software development trend, acting as an alternative to virtualization. This technology includes binding together or packaging up software code and its dependencies, letting it run with uniformity and consistency on any IT infrastructure available. As containerization technologies grow, it benefits developers and operations teams while building a solid IT infrastructure.
With containers, developers create and deploy applications faster and securely. As per the traditional approaches, the developer designs the code for a specific computing environment. When we transfer the code to a new location, the chances of finding bugs and errors are higher. Containerization eliminates the issue of switching between platforms by bundling the code along with the related configuration files, libraries, and dependencies it requires. This container is portable and runs on any platform or cloud, hassle-free.
Let’s now have a look at the major containerization tools.
Major Containerization Tools In DevOps
Once you have decided to use containers, here comes the million-dollar question. What are the most popular tools used for containerization? To ease things, let’s divide the tools into various categories.
Hands down, Docker is the most popular containerization technology. This popular open-source platform is now a key containerization standard, working with other products that follow and open-source tools.
Docker Enterprise, a set of features and additional containerization tools in Docker, needs a special mention, as it gives the company financial support. Docker Enterprise is an opt choice if you would like to get professional support on issues or version management of the platform.
Before we talk about CRI-O, let’s introduce rkt, which is a command-line interface (CLI) to run application containers on Linux. The design makes rkt stable, secure, and composable.
CRI-O, the first Container Runtime Interface implementation, is super lightweight and open-source.
With great redesign and retooling, rktlet is an improvement of rkt. rktlet brings Container Runtime Interface (CRI), a new set of tools and community to rival Docker.
An alternative to Linux, Microsoft container provides support to containers in Windows. Microsoft Containers run in virtual machines (VM), not orchestrators like Kubernetes.
Once you create containers, here comes the hard part – running and supporting them in production. Here come the roles of container orchestration tools, which manage the activities of these containers.
When it comes to cluster (A set of nodes that runs computerized applications) management, Kubernetes is the first container orchestrator that comes to our mind. Developed by Google, this open-source platform supports Amazon’s AWS, Google’s Cloud Engine (GCE), and Microsoft’s Azure Container service. Kubernetes even runs on private cloud platforms like OpenStack, OpenStack. Microsoft, Amazon, and Google. Kubernetes is highly portable, preventing vendor lock-in.
Swarm, Docker’s free tool for cluster management, comes with version 1.12 of Docker or higher and runs on the command line. Traditionally, Swarm does not support auto scaling on load balancing. However, there are third-party extensions to support this feature.
A commercial alternative to Kubernetes, Docker Datacenter embraces and extends the qualities of Docker’s free, open-source products – Docker and Swarm. Oh yes, it works with Docker Enterprise too.
With a design to be a drop-in replacement for Kubernetes, Datacenter lets you containerize your entire data center. With Lightweight Directory Access Protocol (LDAP) and a dashboard with a control panel, registry, monitoring, logging, and continuous integration (CI), Datacenter also has autoscaling and balancing.
Istio and Envoy
While Kubernetes is the most popular container orchestrator, it does not provide the tools to debug services that call services.
Enter Envoy and Istio, two open-source technologies that add a layer of security and observability. These technologies encrypt traffic in the cluster while observing it.
Containers, with a design for interchangeability, work remarkably for web services and microservices. Containers can scale on demand. However, storage of data is an issue. Databases and storage require persistent locations or a standard interface layer to house data. Here is where storage containers are relevant.
An elastic storage platform, BlockBridge offers storage for containers using Docker. The platform provides support for Kubernetes, OpenStack, and storage for other software.
EMC / libstorage
The EMC/libstorage is an open-source, platform-agnostic storage provisioning and orchestration framework, model, and API. This platform is an ideal choice for adding value to upstream applications.
Docker is the most popular container technology for a reason. Various plugins for storage by EMC, NetApp, and others are available on Docker for download.
For any business or technology, the security of sensitive data is the prime factor. The same applies to containers. Auditing, intruder detection and prevention, vulnerability analysis, and LDAP integration are the main pain points a business faces while deploying or migrating their app to containers. Even traditional devices and software find it hard to manage cluster security. However, here are the best options to add security to your clusters.
When we build Docker images out of components like Operating Systems (OS), web servers, or Content Management Systems (CMS), we face the risk of unpatched or outdated software bringing security threats. Powered by a vulnerability scanner, Twistlock compares these Docker images against known threats in their database, which undergoes constant upgrades. Apart from this powerful scan, Twistlock also performs the classic intrusion detection and regulation compliance checks.
Aqua Container Security
Similar to Twistlock, Aqua Container Security creates, monitors, and enforces container policies. Additionally, the platform integrates CI and runs security checks on every app build.
StackRox is known for providing cluster discovery for Kubernetes, examining the entire clusters, and comparing the behavior of running containers to the security policies of a company. The platform documents the policies and evaluates the code automatically.
Most operating systems consist of big pre-existing packages for the convenience of users. Meanwhile, the design of Docker is for it to be lightweight and to run on various virtual machines while having low memory, disk, and CPU usage.
As a response to this need, vendors are customizing Linux distributions to suit the container’s needs. Here are popular OS’s that are specific for containers.
By default, Alpine Linux is the OS you use when creating a Docker image unless specified. A vast number of test and sample Docker containers use Alpine Linux. The OS is fast, small, and relatively secure.
As per Canonical, Ubuntu is the most common OS for containers. Core, a distribution within Ubuntu, has a design specific for containers and the Internet of Things (IoT). With high performance, transactional updates, and small footprints, Ubuntu Core has extreme popularity among developers.
Red Hat Atomic Host
Red Hat Enterprise is a favorite of various businesses. When it comes to using containers, Red Hat Atomic Host is an ideal OS for these businesses. They can harness all the powers and advantages of Red Hat Enterprise Linux 7.
Microsoft Nano Server
Forget Linux for now. Microsoft’s Nano Server is an operating system based on Windows Server 2016. The OS is small, command-line based, and one can administrate remotely. Windows Pro 10 is another Microsoft OS that can host containers.
The next step
With a multitude of popular containerization tools at your hands, embarking on your containerization journey is easier. Additionally, Docker and Kubernetes have a strong community ready to help you at each roadblock. Want to know more about containerization? We are here to help you choose the right tools for each occasion. Say hi to take a step forward in your containerization journey.