fieldproxy

a simple http load balancer by custom header field.

a request with custom header field enter into the proxy server, if the value of the field appears for the first time, then select a server with the least number of bound fields under upstream.

envs

FP_FIELD
FP_OUTTIME
FP_LOG_LEVEL
PROXY_CONSUL_ADDR
PROXY_CONSUL_SERVICE

running

docker run -d \
  -v `pwd`/fieldproxy.yml:/etc/fieldproxy/fieldproxy.yml \
  shinhwagk/fieldproxy:latest \
  --log.level=INFO \
  --config.file=/etc/fieldproxy/fieldproxy.yml

update upstream list

data.json

[
  { "server": "fieldproxy_devcontainer_server_2", "port": 80 },
  { "server": "fieldproxy_devcontainer_server_1", "port": 80 }
]

update upstream

# manaul by curl
curl http://consul:8500/v1/catalog/service/fieldproxy | jq -c '[.[] | (.ServiceAddress+":"+(.ServicePort|tostring))]'
# by consul-template
consul-template -consul-addr "consul:8500" -exec "curl -s http://consul:8500/v1/catalog/service/fieldproxy | jq -c '[.[] | (.ServiceAddress+\":\"+(.Serv
icePort|tostring))]' | curl -XPOST -d @- http://app:8000/upstream"

test: three http request

curl -H "X-multidatabase-dbid: w32" -XPOST http://127.0.0.1:8000/path -d 'body'
curl -H "X-multidatabase-dbid: w33" -XPOST http://127.0.0.1:8000/path -d 'body'
curl -H "X-multidatabase-dbid: w34" -XPOST http://127.0.0.1:8000/path -d 'body'

effect

In 60 seconds(by set outtime)，

http request(w32) & http request(w34) <--> 4db89bc51bc7:8000.
http request(w33) <--> 4db89bc51bc6:8000.

export FP_FIELD=x-multidatabase-dbid
export FP_LOG_LEVEL=DEBUG
export PROXY_CONSUL_ADDR=consul:8500
export PROXY_CONSUL_SERVICE=fieldproxy
export FP_OUTTIME=60

compile

mkdir -p dest; deno compile -o dest/fp --allow-env --allow-net main.ts