logstash /usr/share/logstash/bin/system-install -h | --help message incorrect

[thanh-lam]

• Version: 7.5.1 or newer
• Operating System: RHEL 8.1 or other
• Steps to Reproduce:

1. cd to /usr/share/logstash/bin/
2. Run ./system-install -h or ./system-install --help
3. Note help messages as following:

# ./system-install -h
Usage: system-install [OPTIONSFILE] [STARTUPTYPE] [VERSION]

NOTE: These arguments are ordered, and co-dependent

OPTIONSFILE: Full path to a startup.options file
OPTIONSFILE is required if STARTUPTYPE is specified, but otherwise looks first
in /usr/share/logstash/config/startup.options and then /etc/logstash/startup.options
Last match wins

STARTUPTYPE: e.g. sysv, upstart, systemd, etc.
OPTIONSFILE is required to specify a STARTUPTYPE.

VERSION: The specified version of STARTUPTYPE to use.  The default is usually
preferred here, so it can safely be omitted.
Both OPTIONSFILE & STARTUPTYPE are required to specify a VERSION.

For more information, see https://github.com/jordansissel/pleaserun

The part about OPTIONSFILE is in conflict with the code in the script system-install:

OPTIONSFILE is required if STARTUPTYPE is specified, but otherwise looks first
in /usr/share/logstash/config/startup.options and then /etc/logstash/startup.options
Last match wins

The script looks first in /etc/logstash/startup.options and then `/usr/share/logstash/config/startup.options:

if [ -z "$1" ]; then
  if [ -r /etc/logstash/startup.options ]; then
    OPTIONS_PATH=/etc/logstash/startup.options
  elif [ -r "${LOGSTASH_HOME}"/config/startup.options ]; then
    OPTIONS_PATH="${LOGSTASH_HOME}"/config/startup.options
  fi
elif

[yaauie]

You're right. That is confusing.

There is a note about "Last match wins", but there is no need for us to present it in reverse order like this. I've opened #12146 to address the confusion.

[thanh-lam]

Thank you for the quick response to correct the help message.