apguard

distributed proxy that acts as a rate limiter for downstream http services

Proxy a service in docker compose

docker-compose.yml

version: "3.8"
services:
  apguard:
    image: apguard/rpx:latest
    ports:
      - "9001:80"
    environment:
        - PROXY_CONF=/etc/proxy/conf.yml
    volumes:
        - "./example-conf.yml:/etc/proxy/conf.yml"

  greeter:
    image: apguard/greeter:latest
    ports:
        - "9000:80"

example-conf.yml

destination: http://greeter
rules:
    - name: vegeta-ua
      mode: ua
      pattern: "vegeta"
      delay: 1s

Other modes are

• ip+ua: means the same ip could have different user agents allowed to query the api
• ip: rate limits on ip address only

Usage

1. go mod vendor
2. start the greeter service go run cmd/greeter/main.go
3. start the apguard go run cmd/rps/main.go -exp=30s
4. curl apguard a few times and see the blocked requests curl localhost:9001

greeter logs

kylefelter@iMac apguard % go run cmd/greeter/main.go
2020/10/11 01:57:13 Hello there [::1]:53393

only one request go through to the greeter

apguard logs

kylefelter@iMac apguard % go run cmd/rps/main.go -exp=30s
blocked ip=[::1]:53384(::1) ua=curl/7.64.1
blocked ip=[::1]:53395(::1) ua=curl/7.64.1

3 total requests were made but 2 of the three were blocked because they came from the same ip address

Production usage

default uses in memory as backend but set REDIS_URL to point to a redis instance to have many proxies that know about other requests

Example

find an example in the /example folder

to run the example

go mod vendor
make build && make ex
brew install vegeta # install vegeta if you don't already have it
vegeta attack -duration=15s -rate=1000/s -targets=example/proxy-targets.conf | tee results.bin | vegeta report

Vegeta report

Requests      [total, rate, throughput]         75000, 5000.06, 1.07
Duration      [total, attack, wait]             15.002s, 15s, 1.862ms
Latencies     [min, mean, 50, 90, 95, 99, max]  531.896µs, 34.129ms, 12.518ms, 100.251ms, 140.86ms, 226.763ms, 1.203s
Bytes In      [total, mean]                     192, 0.00
Bytes Out     [total, mean]                     0, 0.00
Success       [ratio]                           0.02%
Status Codes  [code:count]                      200:16  429:74984  
Error Set:
429 Too Many Requests

Vegeta plot