Get a set of parameters from Systems Manager Parameter Store and format them for use as environment variables

get-parameters.sh

#!/usr/bin/env bash

set -o errexit
set -o nounset
set -o pipefail

# As is the classic warning, this is so far light on error handling.
# Get a set of parameters from Systems Manager Parameter Store and format them for use as environment variables
# Usage: ./get-parameters.sh [--export] prefix [prefix...]
# Options:
# --export      Prefix each line with export command

function get_params_by_prefix {
  # PARAMS needs to reflect tab-separated columns, which should be the case. Beware of that for test data explicitly added here
  # Each item in the list should be of the format "/path/to/parameter     value"
  PARAMS=$(aws ssm get-parameters-by-path --recursive --query 'Parameters[*].[Name, Value]' --output text --with-decryption --path "$1")

  for line in "${PARAMS[@]}"; do
    while IFS=$'\t' read -r name value; do
      short="${name##*/}"     # Get just the last part of the name
      short="${short//-/_}"   # Convert dashes to underscores
      echo "${EXPORT}${short^^}=${value}"  # output, uppercase for the key name
    done <<< "${line}"
  done
}

EXPORT=""

if [[ $1 == "--export" ]]; then
  EXPORT="export "
  shift
fi

while [ $# -gt 0 ]; do
  get_params_by_prefix "$1"
  shift
done