Bash script to parse elements of etcd into -e docker params

etcd-to-docker-env

#!/bin/bash
# create global ENVS associated array
declare -A ENVS
# string for the -e vars
environmentVariables=""

##
# set a a bunch of test data
generateTestEnvData(){
  echo "Setting test data"
  etcdctl set /env/test/foo bar 1> /dev/null
  etcdctl set /env/test/bar foo 1> /dev/null
}

##
# Take a key value array and add that into the $environmentVariables string
# $1 = array of data
generateDockerEnvString(){
  echo "generating the docker environment string"

  for i in ${!ENVS[@]]}; do
    val=${ENVS[$i]}
    key="$(echo $i | tr '[:lower:]' '[:upper:]' )"
    echo "---> $key = $val"
    environmentVariables="${environmentVariables}-e $key=$val "
  done
  echo "environment string: $environmentVariables"
}

##
# fetch the data from the segment of etcd specified and convert into a key value array
# presumes the segment is under /env/
# $1 = segment to use on etcd
environmentDataFromEtcd(){
  # if no arg passed, return erro
  if [[ -z $1 ]]; then
    echo "No arugment passed, returning."
    return 1
  fi
  # check the env segment exists
  local notFound=$(etcdctl ls /env/$1 | grep 'Key not found' | wc -l)
  # return error if not found
  if [[ "$notFound" -gt "1" ]]; then
    echo "Environment segment not set, returning."
    return 2
  fi
  echo "fetching data from etcd"
  # loop over the env vars and fetch the data
  for i in `etcdctl ls /env/$1`; do
    key=$(echo $i | sed -r "s#/env/$1/##gi" | tr '[:lower:]' '[:upper:]')
    echo "===> $i becomes $key"
    # fetch the env var
    val=$(etcdctl get ${i});
    if [ -z $val ]; then
      echo "Could not retrive $i, possibly a directory, ignoring"
    else
      ENVS[$key]=${val};
      echo "====> $key = ${ENVS[$key]}"
    fi
  done
  echo "fetched"
}

# create some test data
generateTestEnvData
# fetch from a test area in the etcd env vars
environmentDataFromEtcd "test"
generateDockerEnvString
# output the result:
echo ""
echo "RESULT: ${environmentVariables}"