ssm

ssm.sh

#!/usr/bin/env bash

## ssm
##
## Copyright (c) 2023 Piotr Roszatycki <piotr.roszatycki@gmail.com>, MIT

set -e

if ! command -v aws >/dev/null; then
  echo "Needs aws command."
  open https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html
  exit 1
fi

if ! command -v session-manager-plugin >/dev/null; then
  echo "Needs session-manager-plugin command."
  open https://docs.aws.amazon.com/systems-manager/latest/userguide/session-manager-working-with-install-plugin.html
  exit 1
fi

host=$1
shift

if [[ -z $host ]]; then
  echo "Usage: $0 HOST [--profile PROFILE] ARGS"
  exit 1
fi

stty_restore () {
  stty discard ^O dsusp ^Y eof ^D erase "^?" intr ^C kill ^U lnext ^V quit ^\\ reprint ^R start ^Q status ^T stop ^S susp ^Z werase ^W
}

stty_undef () {
  trap stty_restore EXIT
  stty discard undef dsusp undef eof undef erase undef intr undef kill undef lnext undef quit undef reprint undef start undef status undef stop undef susp undef werase undef
}

args=($@)

profile=${AWS_PROFILE:-default}
for ((i=0; i<${#args[@]}; i++)); do
  if [[ ${args[$i]} == "--profile" ]]; then
    ((i++)) || true
    profile=${args[$i]}
  fi
done

case "$host" in
  i-*)
    stty_undef
    aws ssm start-session --profile "$profile" --target "$host" "${args[@]}";;
  *)
    instance=$(
        aws ec2 describe-instances \
          --profile "$profile" \
          --filters "Name=tag:Name,Values=$host" "Name=instance-state-name,Values=running" \
          --query "Reservations[].Instances[0].InstanceId" \
          --max-items 1 \
          --output text |
        head -n1
    )
    echo Instance: $instance
    if [[ -n $instance ]]; then
      stty_undef
      aws ssm start-session --profile "$profile" --target "$instance" "${args[@]}"
    fi
esac