infra-role-geth/templates/rpc.sh.j2

#!/usr/bin/env bash
# vim: set ft=sh:
set -euo pipefail

URL="http://{{ geth_rpc_addr }}:{{ geth_rpc_port }}/"

METHOD="$1"
shift
PARAMS=("$@")

if [[ -z "${METHOD}" ]]; then
    echo "No method specified!" >&2
    exit 1
fi
if [[ -n "${@}" ]]; then
    PARAMS=$(printf '%s,' "${@}")
    PARAMS="${@%%,}"
else
    PARAMS=''
fi

PAYLOAD="{
  \"id\": 1,
  \"jsonrpc\": \"2.0\",
  \"method\": \"${METHOD}\",
  \"params\": [${PARAMS}]
}"

# The jq script checks if error exists and adjusts exit code.
curl --request POST \
    --silent \
    --max-time 5 \
    --show-error \
    --fail-with-body \
    --header 'Content-type:application/json' \
    --data "${PAYLOAD}" \
    "${URL}" | \
    jq -e '., if .error != null then null|halt_error(2) else halt end'