elasticsearch 包安装方式单点启动多服务

搞调研分别以rpm包的形式布署了es官方版和亚马逊分发版

https://www.elastic.co/guide/en/elasticsearch/reference/current/install-elasticsearch.html

https://opendistro.github.io/for-elasticsearch-docs/

集群拓扑需要单主机起多个node服务,多服务需要多项不同的配置

但可惜的是rpm安装方式以systemd方式启动，再好不过

https://www.elastic.co/guide/en/elasticsearch/reference/current/setting-system-settings.html#sysconfig

Sysconfig fileedit
When using the RPM or Debian packages, system settings and environment variables can be specified in the system configuration file, which is located in:
RPM
/etc/sysconfig/elasticsearch

Debian
/etc/default/elasticsearch

但是systemd内的EnvironmentFile=-/etc/sysconfig/elasticsearch 并不生效，只能唯一更改/etc/default/elasticsearch

个人设置EnvironmentFile=-/etc/sysconfig/elasticsearch 为 EnvironmentFile=-/etc/sysconfig/elasticsearch-node1，配置并不生效，实际还是会以/etc/sysconfig/elasticsearch方式执行

[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-node1

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 a slow startup before the systemd notifier module kicks in to extend the timeout
TimeoutStartSec=75

[Install]
WantedBy=multi-user.target

# Built for packages-7.10.2 (packages)

那要布署多节点就不能用rpm包安装和systemd安装的方案了？

直接用jar包，或docker，都可以解决，如果都用docker了，也考虑能不能上k8s，直接云原生es

但对强存储的服务云原生，还是不放心，想通过裸机部署，裸机部署需要用systemd来管理，需要systemd的启动多节点的解决办法

既然外在表现是更改EnvironmentFile=-/etc/sysconfig/elasticsearch-node1不生效，那是因为es启动脚本一定有强制加载/etc/sysconfig/elasticsearch的地方，找找看

grep '/etc/sysconfig/elasticsearch' /usr/share/elasticsearch/bin/*

/usr/share/elasticsearch/bin/elasticsearch-env:source /etc/sysconfig/elasticsearch

果然

# check the Java version
"$JAVA" "$XSHARE" -cp "$ES_CLASSPATH" org.elasticsearch.tools.java_version_checker.JavaVersionChecker
export HOSTNAME=$HOSTNAME
source /etc/sysconfig/elasticsearch

if [ -z "$ES_PATH_CONF" ]; then
  echo "ES_PATH_CONF must be set to the configuration path"
  exit 1
fi

source /etc/sysconfig/elasticsearch这一行里写死了加载/etc/sysconfig/elasticsearch，所以systemd 配置里EnvironmentFile=-/etc/sysconfig/elasticsearch 并不生效，调整测试

首先 source /etc/sysconfig/elasticsearch 更改为source $ES_SYSCONFIG，从ES_SYSCONFIG 加载真实的配置文件路径

#source /etc/sysconfig/elasticsearch
source $ES_SYSCONFIG

修改systemd 配置，添加传入ES_SYSCONFIG，指定相应配置文件的参数

EnvironmentFile=ES_SYSCONFIG=/etc/sysconfig/elasticsearch-node1

# /usr/lib/systemd/system/elasticsearch.service
[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-node1
EnvironmentFile=ES_SYSCONFIG=/etc/sysconfig/elasticsearch-node1

启动服务，测试生效，问题解决

另可能会有些es权限相关的问题，对需要读写的目录添加授权

chown elasticsearch:elasticsearch /etc/sysconfig/elasticsearch-node1

哪些目录漏掉了，会因为权限问题es启动失败，可以通过es的日志定位到具体目录

elasticsearch 包安装方式单点启动多服务

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