receive

#!/bin/bash

# We need to do a few things here.
# 1) Build the repo
set -e;
APP="$2"; IMAGE="app/$APP"; NAME=$1

META="$HOME/meta"
APPMETA="$META/$NAME"

# Create meta folder
if [ ! -d $META ]; then
  mkdir $META
fi

# Check if the current app already running
if [ ! -f $APPMETA ]; then
 touch $APPMETA # Create the file
fi

PROCID=$(head -1 $APPMETA)
ISRUNNING=false

# Check if it's empty or not
if [ -z "$PROCID" ]; then
 # Empty
 ISRUNNING=false
 echo "-> No old processes found."
else
 ISRUNNING=true
 echo "-> We found old processes running."
fi

function build() {
  echo "++ Building..."
  id=$(cat | docker run -i -a stdin progrium/buildstep /bin/bash -c "mkdir -p /app && tar -xC /app")
  test $(docker wait $id) -eq 0
  docker commit $id $IMAGE > /dev/null
  id=$(docker run -d $IMAGE /build/builder)
  docker attach $id
  test $(docker wait $id) -eq 0
  docker commit $id $IMAGE > /dev/null
}

# 2) Deploy
function deploy() {
  echo "++ Deploying..."
  id=$(docker run -d -p 5000 -e PORT=5000 $IMAGE /bin/bash -c "/start web")
  echo "++ Launched new container"
  if $ISRUNNING ; then
    echo "++ Stopping previous container..."
    docker stop $PROCID
  fi
  echo "++ Cleaning up..."
  rm $APPMETA
  touch $APPMETA
  echo $id > $APPMETA
  echo "-----> Deploy was successful!"
}


build
deploy

Took some parts from Dokku but adjusted it for a different purpose. The goal of this is to create a deploy system for a distributed system. Servers are not directly connected to a domain.

This system assumes that the servers are sitting behind a load balancer of some sort and will use nginx to act as a reverse proxy to work with the dynamic ports that Docker assigns to the containers.

Previous versions of containers are terminated once new versions are up and running. This makes it possible for a zero-downtime deploy.