A simple tool to add rules to haproxy.cfg and reload the Haproxy container. It uses JSON RPC and has Add, Remove, Generate Methods. Please see test.py for usage.
The tool uses go package text/template to generate frontend and backend entries.
const frontendTmpl = "
acl is{{.Acl}} hdr_beg(host) {{.Hostname}}
use_backend {{.Backend}} if is{{.Acl}}
"
const backendTmpl = "
backend {{.Backend}}
server {{.Backend}} {{.Hostname}}:{{.Port}} check inter 10000
"Methods
url = 'http://localhost:34015/haproxy'
addArgs = {'Services':[{'Name':'myapp','Port':'8080','Domain':'.docker.com'},{'Name':'myapp2','Port':'8181','Domain':'.docker.com'}]}
removeArgs = {'Services':[{'Name':'myapp'},{'Name':'myapp2'}]}
args = {}
print rpc_call(url, "Haproxy.Add", addArgs)
print rpc_call(url, "Haproxy.Remove", removeArgs)
# regenerates the config and reloads the container
print rpc_call(url, "Haproxy.Generate", args)Methods to modify global,default and frontend do not exist. Assuming it's one off, we do this manually right now.
Swarm Example
# Prerequisite: Setup a swarm: https://docs.docker.com/engine/userguide/networking/get-started-overlay/
# create overlay network
eval $(docker-machine env --swarm mhs-demo0)
docker network create --driver overlay --subnet=10.0.9.0/24 my-net
# Start hapreload container
docker run -d -v /home/docker/haproxy:/haproxy \
-v /var/run/docker.sock:/var/run/docker.sock \
-e "HAPROXY_CONTAINER_NAME=haproxy" \
-e constraint:node==mhs-demo1 -p 34015:34015 --name hapreload adnaan/hapreload
# Startup a haproxy container in the swarm on mhs-demo1(same node as hapreload)
# start haproxy after hapreload to make sure haproxy.cfg exists
docker run --net=my-net --name haproxy -p 80:80 -d -v \
/home/docker/haproxy/:/usr/local/etc/haproxy \
-e constraint:node==mhs-demo1 haproxy:1.6
# Startup a simple fileserver on the same overlay network
# create another node mhs-demo2 as in the above link
docker-machine ssh mhs-demo2
mkdir -p test && echo "I am myapp" >> test/test && exit
# exit from mhs-demo2 machine
# sample service 1
docker run --net=my-net --net-alias=myapp.docker.com --name simplehttpserver -d -v \
/home/docker/test:/var/www -p 8080 -e constraint:node==mhs-demo2 \
trinitronx/python-simplehttpserver
# sample service 2
docker run --net=my-net --net-alias=myapp2.docker.com --name simplehttpserver -d -v \
/home/docker/test:/var/www -p 8181 -e constraint:node==mhs-demo2 \
trinitronx/python-simplehttpserver
# get machine IP : docker-machine ip mhs-demo1
# add to /etc/hosts
# 192.168.99.102 myapp.docker.com (machine IP)
# add rule to haproxy
./test.py http://192.168.99.102:34015/haproxy add && curl myapp.docker.com/test
I am myapp
# remove rule from haproxy
./test.py http://192.168.99.102:34015/haproxy remove && curl myapp.docker.com/test
<html><body><h1>503 Service Unavailable</h1>
No server is available to handle this request.
</body></html>
Build
Go needs to be installed. If development machine is OSX, please do a cross platform build, as hapreload runs on an alpine image.
GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build .A linux binary has been checked into this repo.
Roadmap
Apart from bug fixes, none. This is a hack. A better solution would be consul template.
This project is inspired from https://github.com/joewilliams/haproxy_join.