68 lines
2.3 KiB
Markdown
68 lines
2.3 KiB
Markdown
---
|
|
title: Proxies in Kubernetes
|
|
content_type: concept
|
|
weight: 90
|
|
---
|
|
|
|
<!-- overview -->
|
|
This page explains proxies used with Kubernetes.
|
|
|
|
|
|
<!-- body -->
|
|
|
|
## Proxies
|
|
|
|
There are several different proxies you may encounter when using Kubernetes:
|
|
|
|
1. The [kubectl proxy](/docs/tasks/access-application-cluster/access-cluster/#directly-accessing-the-rest-api):
|
|
|
|
- runs on a user's desktop or in a pod
|
|
- proxies from a localhost address to the Kubernetes apiserver
|
|
- client to proxy uses HTTP
|
|
- proxy to apiserver uses HTTPS
|
|
- locates apiserver
|
|
- adds authentication headers
|
|
|
|
1. The [apiserver proxy](/docs/tasks/access-application-cluster/access-cluster/#discovering-builtin-services):
|
|
|
|
- is a bastion built into the apiserver
|
|
- connects a user outside of the cluster to cluster IPs which otherwise might not be reachable
|
|
- runs in the apiserver processes
|
|
- client to proxy uses HTTPS (or http if apiserver so configured)
|
|
- proxy to target may use HTTP or HTTPS as chosen by proxy using available information
|
|
- can be used to reach a Node, Pod, or Service
|
|
- does load balancing when used to reach a Service
|
|
|
|
1. The [kube proxy](/docs/concepts/services-networking/service/#ips-and-vips):
|
|
|
|
- runs on each node
|
|
- proxies UDP, TCP and SCTP
|
|
- does not understand HTTP
|
|
- provides load balancing
|
|
- is just used to reach services
|
|
|
|
1. A Proxy/Load-balancer in front of apiserver(s):
|
|
|
|
- existence and implementation varies from cluster to cluster (e.g. nginx)
|
|
- sits between all clients and one or more apiservers
|
|
- acts as load balancer if there are several apiservers.
|
|
|
|
1. Cloud Load Balancers on external services:
|
|
|
|
- are provided by some cloud providers (e.g. AWS ELB, Google Cloud Load Balancer)
|
|
- are created automatically when the Kubernetes service has type `LoadBalancer`
|
|
- usually supports UDP/TCP only
|
|
- SCTP support is up to the load balancer implementation of the cloud provider
|
|
- implementation varies by cloud provider.
|
|
|
|
Kubernetes users will typically not need to worry about anything other than the first two types. The cluster admin
|
|
will typically ensure that the latter types are setup correctly.
|
|
|
|
## Requesting redirects
|
|
|
|
Proxies have replaced redirect capabilities. Redirects have been deprecated.
|
|
|
|
|
|
|
|
|