An example Blue/Green deployment using Tutum and Cloudflare (for DNS)

README.md

Expects one argument the name of the production stack file for Tutum.

(see https://support.tutum.co/support/solutions/articles/5000569899-stacks )

Requires these environment variables to be set

• CLOUDFLARE_DOMAIN - root domain of your app, e.g. example.com
• CLOUDFLARE_KEY - your Cloudflare API key
• CLOUDFLARE_EMAIL - your Cloudflare email address e.g. fred@example.com
• PROJECT_NAME - a short name for your project e.g. example
• TUTUM_USERNAME - your Tutum username
• TUTUM_PASSWORD - your Tutum password
• CLUSTER_SIZE - final cluster size

NB: The script assumes you have a loadbalancer service within your stack called 'lb'. You should have created a node cluster called ${PROJECT_NAME} and it is assumed that you normally have one node in the cluster and expand to 2 during deployment.

tutum_cloudflare_blue_green.sh

#!/usr/bin/env bash

# Expects one argument the name of the production stack file
#
# Requires these environment variables to be set
#
# CLOUDFLARE_DOMAIN - root domain of your app, e.g. example.com
# CLOUDFLARE_KEY - your Cloudflare API key
# CLOUDFLARE_EMAIL - your Cloudflare email address e.g. fred@example.com
# PROJECT_NAME - a short name for your project e.g. example
# TUTUM_USERNAME - your Tutum username
# TUTUM_PASSWORD - your Tutum password
# CLUSTER_SIZE - the initial cluster size (default 1)
#
# NB: The script assumes you have a loadbalancer service within your stack called 'lb'
#     You should have created a node cluster called ${PROJECT_NAME}
#     It is assumed that you normally have one node in the cluster and expand to 2 during deployment.

set -eu
cd $(dirname $0)

cluster_normal_size=${CLUSTER_SIZE:-1}
cluster_expanded_size=$(( cluster_normal_size * 2 ))
project=${PROJECT_NAME}
state=
alt_state=


if ! which tutum
then
    echo "Please install Tutum CLI using 'sudo -H pip install tutum'"
    exit 1
fi

if ! which cfcli
then
    echo "Please install Cloudflare CLI using 'npm install -g cloudflare-cli'"
    exit 1
fi


if (( $# == 0))
then
    echo "Usage: $0 <stack-file>"
    exit 1
fi

echo "Logging in to Tutum"
tutum login -u $TUTUM_USERNAME -p $TUTUM_PASSWORD

echo "Scaling out for blue/green deployment"
tutum nodecluster scale --sync ${project} ${cluster_expanded_size}


if tutum stack list | grep ${project}-blue | grep Running
then
    echo "Current state is blue"
    state=blue
    alt_state=green
else
    echo "Current state is green"
    state=green
    alt_state=blue
fi


while tutum stack list | grep ${project}-${alt_state} | grep -v Terminated
do
    echo "Terminating exisiting ${alt_state} deployment"
    if tutum stack terminate  --sync ${project}-${alt_state}
    then
        echo "Terminated"
    else
        sleep 20
    fi
done

echo "Starting new ${alt_state} deployment"
tutum stack up -n ${project}-${alt_state} --sync -f $1

echo "Changing DNS"

#Change DNS
cfcli --token ${CLOUDFLARE_KEY} --email ${CLOUDFLARE_EMAIL} --domain ${CLOUDFLARE_DOMAIN} --type cname -ttl 120 editrecord ${CLOUDFLARE_DOMAIN}  lb.${project}-${alt_state}.${TUTUM_USERNAME}.svc.tutum.io

echo "Awaiting DNS propagation"
#Wait for DNS change over, we use a fixed time here as we have to wait for all cached DNS records to change before continuing
sleep 240


echo "Terminating exisiting ${state} deployment"
tutum stack terminate  --sync ${project}-${state}

echo "Shrinking back cluster after deployment"
tutum nodecluster scale --sync ${project} ${cluster_normal_size}