Kubernetes is a platform used for managing cloud native applications. Also known as “k8s” or “k-eights,” Kubernetes is an open-source orchestration tool. It is a container-centric management software designed to meet the scaling needs of an organization. Kubernetes is used for providing the means needed for running the management, deployment and scaling of containerized workloads.
Companies’ delivering services on Kubernetes will have multiple Kubernetes clusters, also known as multi-clusters. Kubernetes is a tool that plays a part in hybrid cloud automation, though it does present technology silos. Cloudify, as an agnostic orchestrator, dwindles lock-in, allowing future multi-cloud opportunities.
What is Kubernetes Orchestration?
Kubernetes orchestration allows DevOps to build application services across multiple containers, schedule and scale containers within a single cluster, and manage their health over time. Kubernetes eliminates the need for manual processes for deploying and scaling containerized applications.
Is Kubernetes using Docker?
Kubernetes is a container orchestrator, and therefore depends on a container runtime in order to operate. While it can be used with any container runtime, Kubernetes is most commonly used with Docker. Cri-o, Containerd, and RunC are other container runtimes that can be deployed with Kubernetes. Kubernetes does not always use Docker and Docker can be used without Kubernetes as a more simple container without an orchestrator.
Is Kubernetes an alternative to Docker?
There is a fundamental difference between Kubernetes and Docker: Docker runs on a single node and Kubernetes across a cluster. Kubernetes is a more extensive approach than Docker Swarm, efficiently coordinating clusters of nodes at scale in production.
Kubernetes is not an alternative to Docker, rather, it is an add on to Docker. Docker is a standalone software that can run containerized applications, and Kubernetes is a container orchestrator that can work with Docker and other container runtime systems. Using Kubernetes with Docker allows for automation of tasks like provisioning, deployment, load balancing, and performance monitoring.
What is Multi-Cluster Management?
Organizations will typically run multiple Kubernetes clusters. A multi-cluster environment is more complex than just running multiple clusters. Multi-cluster management aims to ensure consistent operations across all environments, address security challenges and manage complex workloads.
Multi-Cluster management Tools include:
- Amazon EKS: Amazon’s elastic Kubernetes service provides a dashboard that displays workload statistics, metrics, memory, storage consumption and cpu.
- Azure AKS: Azure’s Arc presents resources at various levels and boasts configuration parameters.
- Rancher: Rancher is an open source multi-cluster management tool that through a number of dashboards connects on-prem and cloud providers. Rancher, unlike other tools, focuses on the visibility of the clusters and their metrics as opposed to managing workload across them.
- Cloudify: Cloudify, as an open source multi-cluster management tool, handles not only Kubernetes clusters but also alternative services. Cloudify supports management through CLI and REST API, along with a dashboard panel whereby Kubernetes clusters are displayed in a deployment list.
How do Terraform and Kubernetes Work Together?
Both Terraform and Kubernetes rely on source-controlled configuration files to be used for orchestration. Kubernetes belongs to the “Container Tools” category of the tech stack, while Terraform can be primarily classified under “Infrastructure Build Tools”. Although there is an overlap in scope, most cases don’t allow for one to replace the other. They can, however, work together to provide a full-stack deployment solution.
The biggest benefit when using Terraform to maintain Kubernetes resources is integration into the Terraform plan/apply life-cycle. You can review planned changes before applying them. Also, using kubectl , purging of resources from the cluster is not trivial without manual intervention. Terraform does this reliably.
Why Deploy with Terraform?
Opposed to using kubectl or other CLI-based tools to manage Kubernetes resources, Terraform has the following benefits:
- Unified workflow – If you are already provisioning Kubernetes clusters with Terraform, use the same configuration language to deploy your applications into your cluster.
- Full Lifecycle Management – with a single command Terraform creates, updates, and deletes pods and resources without the need to check APIs that’ll identify these resources
- Graph of Relationships – Terraform understands dependency relationships between resources.
Terraform makes it easy to manage Kubernetes clusters and Kubernetes resources effectively. It gives organizations the opportunity to work with infrastructure-as-code, management of cloud platforms, and also the opportunity to create modules for self-service infrastructure.
Can you use Terraform with Kubernetes?
Yes. Terraform allows users to maintain Kubernetes cluster definitions in the code and to modify them through variables. Terraform is able to use the same configuration language for provisioning and deploying applications into Kubernetes. Terraform honors the relationship between resources and modularizes the infrastructure code as well as using the same syntax for the underlying infrastructure provisioning.