Haproxy X Docker

Dockerfile

FROM haproxy:latest

RUN apt-get update
RUN apt-get install -y netcat-openbsd

COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg

EXPOSE 80

haproxy.conf

global
    log 127.0.0.1 local0 notice
    maxconn 2000
    stats socket /var/run/haproxy.sock mode 600 level admin

defaults
    log     global
    mode    http
    option  httplog
    option  dontlognull
    retries 3
    option redispatch
    timeout connect  5000
    timeout client  10000
    timeout server  10000

frontend gitlab
    bind *:8888
    mode http
    stats enable
    stats refresh 30s
    stats uri /haproxy?stats
    default_backend gitlab

backend gitlab
    balance roundrobin
    mode http
    option httpchk GET /
    http-check expect ! rstatus ^5
    server gitlab1 192.168.99.100:10080 check
    server gitlab2 192.168.99.100:10081 check

run.sh

#!/bin/bash

SLOT1='gitlab1'
SLOT2='gitlab2'

SLOT=`docker exec -it gitlab-haproxy bash -c 'echo "show stat"  | nc -U /var/run/haproxy.sock' | grep DOWN | cut -f2 -d',' | head -n 1`
if [ -z "$SLOT" ]; then
  echo 'No slot is available for docker-compose up'
  exit
fi

cd $SLOT
docker-compose up -d

echo "Waiting the new server to go up ..."
CURRENT=0
TIMEOUT=60
RETRY_EVERY=5
DOWN=$SLOT
while [ $CURRENT -lt $TIMEOUT ] && [ -n "$DOWN" ];
do
  CURRENT=$(($CURRENT+$RETRY_EVERY))
  sleep $RETRY_EVERY
  DOWN=`docker exec -it gitlab-haproxy bash -c 'echo "show stat"  | nc -U /var/run/haproxy.sock' | grep $SLOT | grep DOWN | cut -f2 -d',' | head -n 1`

  echo $CURRENT
  echo $DOWN
done

if [ -n "$DOWN" ]; then
  echo 'Timeout. Failed to stop the old server.'
else
  if [ $SLOT1 == $SLOT ]; then
    cd ../$SLOT2
  else
    cd ../$SLOT1
  fi
  docker-compose stop
fi