ksqlDB Pull Query Bash Demo

ksql-demo.sh

#
# Example Usage:
#     ./get-and-subscribe.sh -t foo -s "user = 'User_6'" will get all rows with `user = 'User_6'` from the foo table
#     ./get-and-subscribe.sh -f -t foo -s "user = 'User_6'" will issue the above query, and also subscribe to changes

usage() { echo "Usage: $0 [-f follow] [-t table] [-s <sql where clause>]" 1>&2; exit 1; }

while getopts "ft:s:" o; do
  case "${o}" in
    t)
      table=${OPTARG}
      ;;
    f) 
      follow=true
      ;;
    s)
      s="${OPTARG}"
      ;;
    *) 
      usage
      ;;
  esac
done

echo ${s}

# SET VARS
HOSTNAME="pksqlc-gkgjv.us-west4.gcp.confluent.cloud"

# escape any string literals - this is a bit hacky
# if there's a string literal with quotes in it, but
# hopefully this works for most cases
sql_escaped=${s//\'/\'\\\'\'}

cmd="curl -H 'Content-Type: json' --http2 -X POST "
cmd+="--user '${KSQL_API_KEY}:${KSQL_API_SECRET}' "
cmd+="-d '{\"sql\":\"SELECT * FROM ${table} WHERE ${sql_escaped};\"}' "
cmd+="https://${HOSTNAME}/query-stream"

eval "$cmd"

if [ "$follow" = true ]; then
  cmd="curl --no-buffer -s -H 'Content-Type: json' --http2 -X POST "
  cmd+="--user '${KSQL_API_KEY}:${KSQL_API_SECRET}' "
  cmd+="-d '{\"sql\":\"SELECT * FROM ${table} WHERE ${sql_escaped} EMIT CHANGES;\"}' "
  cmd+="https://${HOSTNAME}/query-stream"

  eval "${cmd} | grep \"^\[\""
fi