IT professionals, end users, and business owners have different motivations for choosing specific technologies when looking to grow their companies’ web or mobile app presence or provide customers with Software as a Service (SaaS). While IT professionals are often seeking ease of use, end users need flexibility and reliability, and business owners want cost-effective solutions.
Containers — self-contained applications and services that users can easily deploy, update, and scale up or down as needed — meet all of these requirements and more. They are useful in situations like moving software from a test environment to a production environment, when a different version of a software library is running, or when each machine uses a different compiler or loader. In the sections below, we expand on this definition and discuss the benefits, use cases, and how-tos of containers.
When users are looking to ensure software runs as it should when moved from one computing environment to another, containers are useful because they include all dependencies, so they don’t have to be reconfigured across various computing environments. They are also the foundation of Kubernetes, which enables users to deploy multiple containers to multiple hosts. Containers can be distributed via a virtual platform and enable companies to save money by reducing the number of applications and services needed.
Containers are sometimes confused with virtual machines (VMs), which are used by large enterprises to build virtualized computing environments. A VM makes it possible to run multiple operating systems (OS) on one server, which enhances resource utilization. Within each VM, a hypervisor allocates hardware resources including CPU, memory, storage, and networking.
Unlike VMs, containers only run applications and their dependencies and gain access to hardware through capabilities of the host operating system. The following video describes in detail the differences between VMs and containers.
Containers first appeared in the 1970s in conjunction with UNIX chroot and have been evolving since then. By 2019, 20% of companies worldwide were using containers, which are likely to continue to grow in usefulness and importance. Experts predict that, by 2023, more than 70% of organizations worldwide will be running more than 2 containerized applications in production.
Container technology is potentially highly cost-effective, given that the other components required for creating an environment to run them can be acquired for free. For example, Ubuntu Linux is a free host OS, VirtualBox is a free VM platform, and Docker is free deployment software. Granted, some organizations may choose different options for these selections or may need to pay for a larger deployment. But it is possible to create this setup with very little financial investment.
Containers can be used to deploy and scale websites without impacting the operation of other applications and services on a server. So, companies can easily add web-based components to expand their online offerings. Such updates do not require dependencies to be met by the hosting computer. Because containers are isolated and don’t compete for host resources or affect the running of the host machine, administrators don’t have to worry about each application or service impacting the others.
When Containers Can Help
According to a recent Alibaba Cloud blog post, the following are common container use cases:
- Microservice architecture. Microservices need to be deployed and managed independently. Containers provide them with isolated workload environments, making it easy to deploy and scale them independently.
- Multi-cloud deployment. Multi-cloud or hybrid cloud solutions can use containers to deploy applications across different cloud environments and rapidly move them from one cloud environment to another on-premise, to the cloud, or vice-versa.
- Multi-tenancy. In multi-tenancy architecture, a single instance services multiple customers called tenants. This architecture is fast and lightweight, so only takes a few seconds to start.
- Developer productivity and early application development. Developers in the early stages of application development can test a version by spinning a container with dependencies. With this arrangement, developers can worry more about new product features than about environment setup and debugging.
- Easy configuration and DevOps adoption. With containers, users need only put configurations in the code and deploy it. Containers support the continuous integration and continuous delivery and deployment (CI/CD) pipeline for continuous development and DevOps configurations.
How to Use Containers
To start with containers, users should familiarize themselves with tools like Docker and Podman, as well as Linux, writing container manifests in JSON, and the container management platform Kubernetes. The next step is getting Docker up and running to start deploying containers. Cloud Native Wiki recommends the following suggestions as well:
- Use fine-grained components. The smaller the unit, the easier it is to orchestrate.
- Prefer disposable components. When possible, design and build stateless and lightweight containers.
- Implement container security. It is critical to implement security measures and policies across the entire container environment.
- Leverage container orchestrators. A popular open-source option is Kubernetes.
- Automate your pipeline. Automation can help you quickly iterate and make any necessary changes.
- Infrastructure as Code (IaC). IaC lets you define various aspects of the infrastructure in declarative files, which are used to automate the process.
- Practice agile development. Agile methodologies help teams improve the development lifecycle.
- Promote a self-service developer experience. Teams should be able to independently provision their projects.
Does Your Company Need Containers?
Your company may need containers if you have one or more of the following requirements:
- Speed. You can create, replicate, or destroy containers in a matter of seconds.
- Scalability. Because of the speed with which containers can be deployed and destroyed, they support the creation of additional instances of the same application.
- Portability. You need to operate from anywhere, including on a Linux, Windows, or macOS OS, and including virtual machines, bare-metal servers, or a developer’s laptop.
- Resource efficiency. Containers require fewer resources to operate, so a server may run many more of them than VMs.
- Productivity. Developers can create predictable runtime environments that operate consistently, regardless of where they are deployed.