A library of bash functions to use for Amazon Web Services CloudFormation deployments.

functions

#!/bin/bash

# Abort with exit and message
# Used for testing
function abort()
{
  echo " *** ERROR $@"
  exit 1
}

# Delete the stack
# Used for testing and cleaning
function cleanup()
{
  echo " --> Cleaning up"
  echo " --> Deleting CloudFormation stack"
  aws cloudformation delete-stack --stack-name $STACK_NAME
  echo "Finished at $(date -u +%Y-%m-%dT%H:%M:%S%z)"
}

# Configure the awscli
function configure_awscli()
{
  # Configures the aws-cli, requires an access key is and secret
  aws configure --profile $AWS_DEFAULT_PROFILE
}

# Create the stack in Cloudformation
# - not generic, yet.
function create_stack()
{
  echo " --> Creating Cloudformation stack"
  # Creates a CloudFormation stack for the ECS cluster
  aws cloudformation create-stack \
    --stack-name $STACK_NAME \
    --template-body file://cloudformation.json \
    --capabilities CAPABILITY_IAM \
    --notification-arns "$CF_NOTIFICATION_TOPIC_ARN" \
    --parameters $PARAMETERS > /dev/null
}

# Source the environment.variables 
# See environment.variables.example
function source_envs()
{
  export VERSION=`cat VERSION`
  export IPADDRESS=`curl -s http://whatismijnip.nl |cut -d " " -f 5`

  # Source Environment variables if present
  if [ -e "environment.variables" ]; then
    echo " --> Sourcing environment variables"
    source environment.variables
  fi
}

# Test for aws and cURL
function test_prerequisites()
{
  echo " --> Testing for awscli"
  which aws > /dev/null 2>&1
  echo " --> Testing for cURL"
  which curl > /dev/null 2>&1
}

# Function to query Amazon for the CF stack progress
# Exits when complete or delete/delete-failed
function watch_stack_progress()
{
  echo " --> Watching stack progress, please wait..."
  STACK_STATUS=CREATE_IN_PROGRESS
  SLEEP=60
  n=0
  while [ "$STACK_STATUS" == "CREATE_IN_PROGRESS" ]; do
    STACK_STATUS=`aws cloudformation describe-stacks --stack-name $STACK_NAME --query Stacks[*].StackStatus --output text`
    n=$[n+1]
    echo " --> Stack status after ${n}m: $STACK_STATUS"
    if [[ ( "$STACK_STATUS" == "CREATE_COMPLETE" ) || ( "$STACK_STATUS" == "DELETE_COMPLETE" ) || ( "$STACK_STATUS" == "DELETE_FAILED" ) ]]; then
      break
    fi
    sleep $SLEEP
  done
}

# Test for endpoint 
# Requires the $HOST and $DNS_DOMAIN variables to be set
function test_endpoint()
{
  HOSTNAME=$HOST.$DNS_DOMAIN
  PROTOCOL=${PROTOCOL:-https}
  URL_PATH=${URL_PATH:-""}
  URL=$PROTOCOL://${HOSTNAME}${URL_PATH}
  echo " --> Testing for endpoint"
  # Number of requests
  TIMEOUT=30
  # Time to wait between requests
  SLEEP=60
  # Initial HTTP code, should not be 200
  HTTP_CODE="500"
  while [ $TIMEOUT -gt 0 -a $HTTP_CODE -ne 200 ]; do
    TIMEOUT=$[$TIMEOUT-1]
    HTTP_CODE=`curl -o /dev/null -k --silent --head --write-out '%{http_code}' $URL`
    if [ $HTTP_CODE -eq 200 ]; then 
      break 
    fi
    echo " --> GET $URL http_code:$HTTP_CODE ($[TIMEOUT-i] remaining) "
    sleep $SLEEP
  done

  if [ $HTTP_CODE -eq 200 ]; then 
    echo " --> Connection to endpoint was successful"
    exit 0
  else
    echo " --> All requests to endpoint failed, aborting"
    exit 1
  fi
}

# Initialise by sourcing environment variables
source_envs