ssm-session

#!/usr/bin/env bash
#
# Based on https://github.com/corrupt952/ssm-session
#
# Requirements: 
#   - fzf (brew install fzf)
#
# Usage:
#   Designed to be used to with `aws-vault`:
#
#   List avialable instances:
#     aws-vault exec <profile> -- ssm-session list
#
#  Connect to instance (uses fzf to provide interactive list)
#    aws-vault exec <profile> -- ssm-session start

set -o pipefail

ssm_instance_ids () {
  aws ssm describe-instance-information\
    --query "InstanceInformationList[].InstanceId" \
    --output=text 
  }

list_instances () {
  instance_ids=$(ssm_instance_ids)

  aws ec2 describe-instances \
    --instance-ids ${instance_ids} \
    --filter "Name=instance-state-name,Values=running" \
    --query "Reservations[*].Instances[*].[InstanceId,Tags[?Key=='Name']|[0].Value]" \
    --output text
  }

print_usage () {
    cat <<-EOF
usage: ssm-session <command>
command:
    list:  List target sessions
    start: Start session manager
EOF
}


case "$1" in
  list )
    list_instances

    ;;
  start )
    # Ignore SIGINT(Ctrl-C) to prevent accidental exit from session
    trap '' 2

    list_instances \
      | fzf \
      | cut -f 1 \
      | xargs -o aws ssm start-session --target

    ;;
  * )
    print_usage
;;
esac