it is used in various contexts to describe a component that acts as a bridge or interface between two systems or layers. Adapters are typically associated with enabling integration or translating data between tools or APIs within the Kubernetes ecosystem.
Here are some common adapters:
- Metrics Adapters Metrics adapters are components that extend the Kubernetes metrics APIs, such as the Custom Metrics API or the External Metrics API. They enable Kubernetes components (like the Horizontal Pod Autoscaler) to retrieve custom or external metrics from sources other than the default metrics server (e.g., Prometheus or external monitoring systems). Examples: Prometheus Adapter: Integrates Prometheus metrics into Kubernetes for scaling workloads based on custom metrics. External Metrics Adapters: Allow Kubernetes to use metrics from cloud providers or external systems for autoscaling.
- Logging or Monitoring Adapters Some logging and monitoring systems use adapters to connect Kubernetes with their backend systems. Example: An adapter that collects logs from Kubernetes Pods and forwards them to a centralized logging system like Fluentd, Elastic Stack, or Loki.
- Networking Adapters In networking, adapters might be implemented to bridge Kubernetes networking with external systems or legacy networks. Example: Adapters that configure ingress controllers or service meshes to work with specific networking setups.
- Cloud Provider Adapters Adapters might also be used to integrate Kubernetes with cloud provider services. Example: An adapter that translates Kubernetes storage class requests into cloud provider-specific API calls for provisioning persistent volumes.
- Custom Adapters Organizations sometimes create custom adapters to integrate Kubernetes with proprietary or less common external systems. If you're referring to a specific "adapter" mentioned in Kubernetes documentation or tooling, it might belong to one of these categories. If you can provide more context or the name of the tool or system, I can provide a more precise explanation!
examples of adapters:
- CNI Plugins (Container Network Interface Adapters) Kubernetes uses the CNI (Container Network Interface) specification for container networking. CNI plugins are network adapters that implement this specification to provide networking functionality in Kubernetes. Examples:
- Calico: Provides networking and network security for containers and Kubernetes. Supports policy-driven networking.
- Flannel: A simple overlay network for Kubernetes.
- Weave Net: Provides container networking with automatic network topology management.
- Cilium: Focuses on networking, security, and observability with eBPF.
- Canal: Combines Flannel and Calico for simple overlay networking with network policies.
- Service Mesh Adapters Service mesh adapters integrate Kubernetes with service mesh technologies to provide advanced traffic management, security, and observability. Examples:
- Istio CNI Adapter: Integrates Istio's service mesh capabilities with Kubernetes networking.
- Linkerd CNI: Provides a lightweight service mesh that works as a network adapter for Kubernetes.
- Consul Connect Adapter: HashiCorp's service mesh that integrates with Kubernetes networking.
- Ingress Controller Adapters Ingress controllers act as adapters to connect Kubernetes Ingress resources with external load balancers or proxies. Examples:
- NGINX Ingress Controller: Adapts Kubernetes Ingress resources to configure an NGINX-based load balancer.
- HAProxy Ingress: A high-performance ingress controller that uses HAProxy.
- Traefik: A modern, cloud-native reverse proxy and load balancer.