Container technology has been enabling application development teams to create individual containers to develop, test, and manage different components of an application. Since each container is packed with all dependencies, it gets extremely easy to host or ship this container across environments – without any issues.
Docker and Kubernetes are two such tools that are ruling the container world, but determining which tool to choose for what application can get intimidating.
Docker is a containerization platform that allows for applications to be run within virtual containers, thus simplifying their development and deployment across a broader environment. Since it wraps all the packages and configurations within individual containers, it enables teams to move applications from a local environment to the production environment – without hassle.
Kubernetes is a container orchestration platform that allows for containers to be run across multiple nodes and clusters. Using Kubernetes, teams can automate the deployment, scaling, and management of containerized applications while providing all the APIs needed for applications to be scaled across multiple servers.
Although Docker and Kubernetes are both used synonymously with container technology, both offer different features and are suited for different requirements.
- Simple applications: Although Docker is recommended for all types of applications, it provides several benefits for simple ones. It allows teams to combine all the packages and configurations needed to run the application in container images. Using Docker Hub, these images can then be shared with other members – within the local network or across the Internet.
- Fast installation: If you want to install your applications quickly and efficiently, Docker is the right choice due to its speed and ease of use. Since Docker allows applications to be run in isolation – without relying on a separate operating system – teams can save massively on hardware resources, while ensuring the application runs efficiently and reliably across computing environments.
- Fault tolerance: Docker is a great choice for teams looking to build fault-tolerant applications. The manager quorum is a key architectural feature of Docker that stores information about every cluster: right from what notes are in the cluster, resources who are managing these clusters, and more. Such information throws light on each cluster’s behavior in the face of failure while allowing teams to better understand the tolerance level due to planned or unplanned outages.
- Customization: For teams that have high customization requirements, Docker allows for custom images to be built using custom code and configurations. Such customizations can easily be done on a local runtime environment while all modifications can be easily documented using the Dockerfile. All teams need to do is provide the docker engine with custom instructions on how to install and configure packages and files, and allow Docker to automatically reads the Dockerfile, execute the instructions, and return a final image.
- Scalable orchestration: When applications grow in scope, spanning multiple containers and deployed across multiple servers, operating them becomes complex. For such applications, container orchestration platforms like Kubernetes can then be used to provide all the APIs needed to control how and where containers will run, especially if they need to be scaled. With Kubernetes, teams can be sure that their complex applications are running the way they should – while enjoying increased responsiveness due to its inherent automatic scaling feature.
- High availability: Kubernetes’ self-healing capability also makes it the ideal choice for applications that need high availability. The container orchestration tool automatically detects when a problem occurs and takes corrective action to rectify it – allowing teams to improve availability, simplify deployments, and minimize downtime. Because it makes sure that changes are correctly implemented before turning off the old version of the application, there is hardly ever an interruption in the performance or functionality of the application at hand.
- Multi-platform requirement: Applications that need to be deployed across multiple platforms need to be able to perform consistently. Since Kubernetes is vendor-agnostic, it works just the same way on every system: whether you’re using Amazon or Azure or an on-premises system, it can consistently manage your clusters and ensure the application runs reliably across all platforms.
- Cluster implementation: Unlike Docker that usually runs on a single node, Kubernetes is designed to run across clusters. By allowing teams to run containers across multiple compute nodes, it ensures containers can be scaled up and down – depending on the need at any given time. Using Kubernetes, teams can leverage an infrastructure-level framework for orchestrating containers as well as managing user interaction between different clusters.
Although there are certain scenarios where Docker and Kubernetes are better and they both have their own advantages and disadvantages, using both together can open doors to additional benefits and opportunities. Since Docker is the foundation on which Kubernetes sits, and with most of Kubernetes documentation written with Docker in mind, together they can provide a well-integrated, comprehensive platform for container deployment, orchestration, and management at scale.