awsenv

#!/usr/bin/env bash
# Set the AWS environment for CLI usage using environment variables
# To run: eval $(awsenv <aws_profile_name>)

# AWS CLI
# Valid options for AWS_DEFAULT_OUTPUT:
# json: good for processing with `jq`
# text: (recommended with --query option) good for processing with *nix tools (tab-delimited)
# table: can be a bit more human readable
: ${AWS_DEFAULT_OUTPUT:="json"}
: ${AWS_CONFIG_FILE:="${HOME}/.aws/config"}
: ${AWS_CREDENTIAL_FILE:="${HOME}/.aws/credentials"}
: ${AWS_DEFAULT_REGION:="us-east-1"}

prg=${BASH_SOURCE##*/}
prg_version="1.1.0"

log() {
  # Write messages to screen
  echo "$(date +"%F %T") [${prg}] $1"
}

usage() {
cat <<EOM

${prg}

Setup your local environment to use AWS based on provided profile.

Usage: ${prg} [options] [profile]

The [profile] specified must exist in the provided AWS credentials. By default
this is the file ~/.aws/credentials as set in the environment variable, AWS_CREDENTIAL_FILE.
To use a different file set the environment variable to the required file.

OPTIONS:
  -h, --help
      Output help (this message)

  -v=, --version
      Output version.

EOM
}

version() {
cat <<EOM

${prg} v${prg_version}

EOM
}

set_env() {
  echo export AWS_DEFAULT_OUTPUT=${AWS_DEFAULT_OUTPUT}
  [[ -f ${HOME}/.aws/config ]] && [[ -z ${AWS_CONFIG_FILE} ]] && echo export AWS_CONFIG_FILE=${AWS_CONFIG_FILE}
  [[ -f ${HOME}/.aws/credentials ]] && [[ -z ${AWS_CREDENTIAL_FILE} ]] && echo export AWS_CREDENTIAL_FILE=${AWS_CREDENTIAL_FILE}
  [[ -z ${AWS_DEFAULT_REGION} ]] && echo export AWS_DEFAULT_REGION=${AWS_DEFAULT_REGION}

  # Read from the files to set the environment using profiles if provided
  awsCreds=( $(awk -F ' *= *' '{ if ($1 ~ /^\[/) section=$1; else if ($1 !~ /^$/) print section "=" $1 "=" "" $2 "" }' ${AWS_CREDENTIAL_FILE} | grep -v "##") )
  for rl in "${awsCreds[@]}"; do
    profile=$(echo "${rl}" | cut -d"=" -f1)
    if [[ "${profile}" == "[${arg}]" ]]; then
      key=$(echo "${rl}" | cut -d"=" -f2)
      value=$(echo "${rl}" | cut -d"=" -f3)
      if [[ "aws_access_key_id" == ${key} ]]; then
        echo export AWS_ACCESS_KEY_ID=${value}
      elif [[ "aws_secret_access_key" == ${key} ]]; then
        echo export AWS_SECRET_ACCESS_KEY=${value}
        echo export AWS_PROFILE=${arg}
      elif [[ "aws_session_token" == ${key} ]]; then
        echo export AWS_SESSION_TOKEN="${value}"
      fi
    fi
  done
}

# Process command line
for arg in "$@"; do
  if test -n "$prev_arg"; then
    eval "$prev_arg=\$arg"
    prev_arg=
  fi

  case "$arg" in
    -*=*) optarg=`echo "$arg" | sed 's/[-_a-zA-Z0-9]*=//'` ;;
    *) optarg= ;;
  esac

  case $arg in
    -h | --help)
      usage && exit 0
      ;;
    -v=* | --version)
      version && exit 0
      ;;
    -*)
      log "Error - Unknown option ${arg}. Exiting."
      exit 1
    ;;
  esac
done

set_env