update .ssh/config with CloudFormation stack IPs

guess_account.sh

#!/bin/bash

aws_credentials_file=${HOME}/.aws/credentials
script_name=`basename $0`

error(){
  echo "[${script_name}] Error: $@. Exiting."
  exit 1
}

# set case insensitive for following regexp
shopt -s nocasematch

environment=$1
[[ ! "${environment}" =~ (DEV|QA|UAT|PREPROD|PROD) ]] && error "ENV <QA|UAT|PREPROD|PROD> should be passed as first parameter."

[[ -z "${project}" ]] && error "'project' environment variable must be set."

#echo "env=${environment} proj=${project}"

case $environment in
dev|qa|uat)
  aws_account="dev-account"
  ;;
test)
  aws_account="test-account"
  ;;
preprod|prod)
  aws_account="prod-acount"
  ;;
*)
  error "ENV '${environment}' must be part of these: QA|UAT|PREPROD|PROD."
  ;;
esac

matched_account_name=`cat $aws_credentials_file | grep "^\[.*${aws_account}" | head -1 | sed -E 's/\[(.*)\]/\1/'`
[[ -z "${matched_account_name}" ]] && error "AWS account '${aws_account}' not existing in ${aws_credentials_file}."
echo ${matched_account_name}

update_cfn_stack_ips.sh

#!/bin/bash

[[ -z $BASH_SOURCE ]] && export BASH_SOURCE=$0
script_name=`basename $BASH_SOURCE`
script_path=`dirname $BASH_SOURCE`
ssh_config_file=$HOME/.ssh/config

error(){
  echo "[${script_name}] Error: $@"
  exit 1
}

[[ -z "${ENVIRONMENT}" ]] && error "Environment variable 'ENVIRONMENT' should be set to one of these <QA|UAT|PREPROD|PROD>."

aws_account=`${script_path}/guess_account.sh $ENVIRONMENT`
[[ -z "${aws_account}" ]] && error "<aws account name> missing"

aws_cmd(){
  AWS_COMMAND=$@
  aws --profile ${aws_account} --region ap-southeast-2 $AWS_COMMAND
}

STACK_NAME=$1
[[ -z "${STACK_NAME}" ]] && error "STACK_NAME parameter missing!!

Available stacks:
`aws_cmd cloudformation list-stacks --stack-status-filter CREATE_COMPLETE | jq -r '.StackSummaries[].StackName' | sed -E 's/^/- /'`
"

#echo "Fetch autoscaling group..." && aws_cmd cloudformation list-stack-resources --stack-name $STACK_NAME > stack_resources
AUTOSCALING_GROUPS=`aws_cmd cloudformation list-stack-resources --stack-name $STACK_NAME | jq '.StackResourceSummaries | map( select(.["ResourceType"] == "AWS::AutoScaling::AutoScalingGroup") )[].PhysicalResourceId'`

for AUTOSCALING_GROUP in $AUTOSCALING_GROUPS; do

  echo "AUTOSCALING_GROUP=$AUTOSCALING_GROUP"

  aws_cmd ec2 describe-instances --filters "Name=tag:aws:autoscaling:groupName,Values=$AUTOSCALING_GROUP" "Name=instance-state-name,Values=running" | jq -r '.Reservations[].Instances[] | .Tags as $tags | .NetworkInterfaces[0].PrivateIpAddresses[0].PrivateIpAddress as $ip | ($tags|map(select(.Key=="Name"))|.[].Value) as $app | ($tags|map(select(.Key=="Environment"))|.[].Value) as $env | .Placement.AvailabilityZone as $az | [$app, $env, $az, $ip ] | join(":")' | while read instance; do

    app=`echo $instance | cut -f1 -d ':'`
    az=`echo $instance | cut -f3 -d ':'`
    env=`echo $instance | cut -f2 -d ':'`
    az_count_name=`echo $instance | cut -f3 -d ':' | sed 's/-//g'`
    ip=`echo $instance | cut -f4 -d ':'`

    eval `echo ${az_count_name}=$[${az_count_name=0} + 1]`
    name="${app}_${env}_${az}_${!az_count_name}"

    if grep "$name" $ssh_config_file >/dev/null 2>&1; then
      echo "Updating $name to $ip"
      perl -0777 -pi -e "s/(Host.*${name}.*\n.*Hostname).*/\1 $ip/i" $ssh_config_file
    else
      echo "ERROR: $name not found in $ssh_config_file"
    fi
  done

done