name: Chapter-5 class: title

Chapter 5

Service Discovery

name: Service-Discovery-Intro class: img-right compact Service Discovery - Intro ————————- .center[:scale 100%]

??? The starting point for networking with Consul is the service registry. This integrates health checks and provides DNS and API interfaces to enable any service to discover and be discovered by other services.

Consul can be integrated with other services that manage existing north-south traffic such as a traditional load balancers, and distributed application platforms such as Kubernetes, to provide a consistent registry and discovery service across multiple data centers, clouds, and application platforms.

name: Service-Discovery-Lab-Servers class: img-right compact Service Discovery - Servers ————————- .center[:scale 100%]

??? Consul’s service discovery is backed by a service catalog. The catalog maintains the high-level view of the cluster and is used to expose this information via the various interfaces Consul provides, including DNS and HTTP.

The catalog is maintained only by server nodes because it’s replicated via the Raft log to provide a consolidated and consistent view of the cluster.

name: Service-Discovery-Lab-Clients class: img-right compact Service Discovery - Clients ————————- .center[:scale 100%]

??? Each Consul agent maintains its own set of service registrations and health checks to include overall node health. The agents are responsible for executing their own health checks and updating their local state.

name: Service-Discovery-Registration Service Discovery - Config ————————- .center[:scale 45%] .center[Nginx example]

??? Configuring a service is pretty straight-forward. Here’s an example of a config file to register a simple NGINX service, the health check simple HTTP query on port 80.

name: Service-Registry-API Service Registry - API Interface ————————- .center[:scale 45%] .center[API Catalog Request]

??? There are a couple of different ways to discover services. The first is by using the API. The example here uses curl, which is convenient for shell scripts. Applications can do direct HTTP requests using a library that fits the language they are using.

name: Service-Registry-DNS Service Registry - DNS Interface ————————- .center[:scale 45%] .center[DNS Catalog Request]

??? The second way is by using DNS. You can query consul using standard hostname resolution either on the command line using tools like dig, nslookup or host, or within applications using native libraries for hostname resolution.

name: Service-Registry-UI Service Registry - UI Interface ————————- .center[:scale 60%] .center[UI Catalog Request]

??? Finally, you can login to the Consul UI and lookup the details in the web UI.

name: Service-Registry-Integration-Consul-Template class: img-right compact Integrations - Consul Template ————————- .center[:scale 100%]

??? Rolling out service discovery doesn’t need to be complicated. Consul Template is a standalone application that populates values from Consul and dynamically renders updates to any third party configuration files.

A common use case is managing load balancer or proxy configuration files that need to be updated in near-real time. In this way, applications that are not Consul aware can benefit from its dynamic capabilities.

It is also ideal for replacing complicated API queries that often require custom formatting.

name: Service-Registry-Integration-DNS class: img-right compact Integrations - DNS ————————- .center[:scale 100%]

??? Using DNS is a simple way to integrate Consul into an existing infrastructure without any high-touch integration.

name: Service-Registry-Integration-Native class: img-right compact Integrations - API/Native ————————- .center[:scale 100%]

??? By leveraging Consul’s RESTful HTTP API system, the community and vendors are able to integrate with Consul’s service registry capabilities.

These integrations include SDKs, load balancers, proxies, API gateways, monitoring tools, and more.

If your application is Consul aware, it can connect directly to the API!

name: Service-Registry-Integration-Native class: img-right compact Example - Native Consul Integration with F5 BIG-IP ————————- .center[:scale 100%]

F5 BIG-IP AS3 서비스 검색 통합은 큰 변경없이 구성 가능하며, Consul의 카탈로그를 쿼리하여 주어진 서비스의 변경 사항에 대한 업데이트를 가져오기 때문에 별도의 운영자 개입없이 동적으로 노드 풀을 조정합니다.

.center[ HashiCorp F5 Consul Webinar ]

.center[ Webinar Demo Repo ]

.center[ F5 Consul Docs ]

??? We’ve been working tirelessly with our partners to provide solid and reliable integrations with the tools you may already have. One of those partners is F5. The resources on this page will show you how to dynamically configure your F5 BIG-IP load balancers so you can help your engineering team automate software delivery.

name: Service-Discovery-Lab

👩‍💻 Lab Exercise: Service Discovery

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(강사가 실습 환경을 위한 URL을 제공합니다.)