generate rabbitmq password has.

generate_rmq_pass_hash.sh

#!/usr/bin/env bash

# copied from https://gist.github.com/lukebakken/7b4da46ed9abb7ed14f7a60b49f9e52e
# discussion from here: https://groups.google.com/forum/#!topic/rabbitmq-users/Brx3tSmNC_8

set -o errexit
set -o nounset

declare -r passwd="${1:-newpassword}"

declare -r tmp0="$(mktemp)"
declare -r tmp1="$(mktemp)"

function onexit
{
    rm -f "$tmp0"
    rm -f "$tmp1"
}

trap onexit EXIT

dd if=/dev/urandom of="$tmp0" count=4 bs=1 > /dev/null 2>&1
cp -f "$tmp0" "$tmp1"
echo -n "$passwd" >> "$tmp0"
openssl dgst -binary -sha256 "$tmp0" >> "$tmp1"
openssl base64 -A -in "$tmp1"