API Gateway

API Gateway 是什麼？

1. 架構彈性 - 當伺服器架構需要調整的時候，Client 不需要調整（前提是 API 維持不變）。
2. 安全性 - Internet 的使用者都無法直接存取 API Gateway 後面的 service，只能透過 API Gateway 間接存取。所以 service 可開放存取的 API 是有限的，降低惡意使用者攻擊的範圍。

API Gateway 的功能

Load balancing

## Dynamic configuration
http:
  services:
    my-service:
      loadBalancer:
        servers:
        - url: "http://<private-ip-server-1>:<private-port-server-1>/"
        - url: "http://<private-ip-server-2>:<private-port-server-2>/"

Authentication and Authorization

# Declaring the user list
apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: test-auth
spec:
  basicAuth:
    secret: authsecret
---
# Note: in a kubernetes secret the string (e.g. generated by htpasswd) must be base64-encoded first.
# To create an encoded user:password pair, the following command can be used:
# htpasswd -nb user password | openssl base64
apiVersion: v1
kind: Secret
metadata:
  name: authsecret
  namespace: default
data:
  users: |2
    dGVzdDokYXByMSRINnVza2trVyRJZ1hMUDZld1RyU3VCa1RycUU4d2ovCnRlc3QyOiRhcHIxJGQ5
    aHI5SEJCJDRIeHdnVWlyM0hQNEVzZ2dQL1FObzAK

request routing

protocol translation

Rate-Limiting

IP Listing

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: test-ipwhitelist
spec:
  ipWhiteList:
    sourceRange:
      - 127.0.0.1/32
      - 192.168.1.7

monitoring