I found the following in directories /lib/systemd/system and /etc/systemd/system
[Unit]
Description=Elasticsearch
Documentation=
https://www.elastic.co
Wants=network-online.target
After=network-online.target
[Service]
Type=notify
RuntimeDirectory=elasticsearch
PrivateTmp=true
Environment=ES_HOME=/usr/share/elasticsearch
Environment=ES_PATH_CONF=/etc/elasticsearch
Environment=PID_DIR=/var/run/elasticsearch
Environment=ES_SD_NOTIFY=true
#EnvironmentFile=-/etc/sysconfig/elasticsearch
EnvironmentFile=/etc/sysconfig/elasticsearch
WorkingDirectory=/usr/share/elasticsearch
User=elasticsearch
Group=elasticsearch
ExecStart=/usr/share/elasticsearch/bin/systemd-entrypoint -p ${PID_DIR}/elasticsearch.pid --quiet
# StandardOutput is configured to redirect to journalctl since
# some error messages may be logged in standard output before
# elasticsearch logging system is initialized. Elasticsearch
# stores its logs in /var/log/elasticsearch and does not use
# journalctl by default. If you also want to enable journalctl
# logging, you can simply remove the "quiet" option from ExecStart.
StandardOutput=journal
StandardError=inherit
# Specifies the maximum file descriptor number that can be opened by this process
LimitNOFILE=65535
# Specifies the maximum number of processes
LimitNPROC=4096
# Specifies the maximum size of virtual memory
LimitAS=infinity
# Specifies the maximum file size
LimitFSIZE=infinity
# Disable timeout logic and wait until process is stopped
TimeoutStopSec=0
# SIGTERM signal is used to stop the Java process
KillSignal=SIGTERM
# Send the signal only to the JVM rather than its control group
KillMode=process
# Java process is never killed
SendSIGKILL=no
# When a JVM receives a SIGTERM signal it exits with code 143
SuccessExitStatus=143
# Allow
I fonund that this command " ExecStart=/usr/share/elasticsearch/bin/systemd-entrypoint -p ${PID_DIR}/elasticsearch.pid --quiet" is used to stand up elasticsearch using Docker. I looked at the code in an earlier version that works, and the above was not found in either directory.
The earlier version contains a startup script in /etc/rec3.d/S80elasticsearch and /etc/rc5.d/S80elasticsearch. It is also found in /etc/inet.d.