Repeat request to host using curl untill it return specified http code

wait-for-http-code.sh

#/bin/sh

HOST=${1}
ATTEMPTS=${2:-10} # -1 for unlimited
CODE=${3:-200}
OUT=${4:-/dev/null}
DELAY=${5:-1s}

case "$HOST" in
"" | "-h" | "--help")
    echo "
Repeat request to HOST(1) ATTEMPTS(2 = 10) times with DELAY(5 = 1s)
untill it return CODE(3 = 200) http code. Write output to OUT(4 = /dev/null)"
    exit 1
    ;;
esac

if [[ "$OUT" = "/dev/null" ]]; then
    GET_BODY="I"
else
    GET_BODY=""
fi

CURL="curl -${GET_BODY}so ${OUT} -w %{http_code} ${HOST}"

until [ $ATTEMPTS -eq 0 ]; do
    [ `$CURL` -eq $CODE ] && exit 0
    [ $ATTEMPTS -gt 0 ] && [ $((--ATTEMPTS)) ]
    [ $ATTEMPTS -gt 0 ] && sleep $DELAY
done

exit 1