第2节.Nacos启动脚本文件说明

Nacos本质是一个基于SpringBoot开发的应用程序，所以它的启动脚本对于我们来说也是很有学习意义的，这里以Linux的脚本的为例进行说明。

脚本的最终目的就是拼接一个java启动命令，并进行执行。

1.脚本支持的外部参数

脚本具有几个默认的参数：

-m参数：指定启动模式，单机(standalone)还是集群(cluster)

-f参数：指定功能模式，配置中心还是注册中心

-s参数：指定服务JAR包名称(nacos-server)

-c参数：指定集群成员列表，最终会传给-Dnacos.member.list命令行属性

-p参数：指定存储模式，内嵌数据库还是外置数据库

当知道了这几个参数以后，脚本大概的逻辑也就基本清楚了。

2.脚本支持的基本功能

1、检查JAVA_HOME环境变量是否存在

2、获得5个参数的默认值

3、设置内存参数设置，单机默认512M，非单机2G

4、设置开放功能模式、集群成员列表参数

5、设置GC启动参数

6、设置nacos主目录、日志文件、spring文件等

7、nohup后台运行nacos服务

3.脚本注释说明

#!/bin/bash

# Copyright 1999-2018 Alibaba Group Holding Ltd.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

cygwin=false
darwin=false
os400=false
case "`uname`" in
CYGWIN*) cygwin=true;;
Darwin*) darwin=true;;
OS400*) os400=true;;
esac
# 定义退出函数
error_exit ()
{
    echo "ERROR: $1 !!"
    exit 1
}
# 各种位置取出JAVA_HOME环境变量
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=$HOME/jdk/java
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/usr/java
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/opt/taobao/java
[ ! -e "$JAVA_HOME/bin/java" ] && unset JAVA_HOME

if [ -z "$JAVA_HOME" ]; then
  if $darwin; then

    if [ -x '/usr/libexec/java_home' ] ; then
      export JAVA_HOME=`/usr/libexec/java_home`

    elif [ -d "/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home" ]; then
      export JAVA_HOME="/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home"
    fi
  else
    JAVA_PATH=`dirname $(readlink -f $(which javac))`
    if [ "x$JAVA_PATH" != "x" ]; then
      export JAVA_HOME=`dirname $JAVA_PATH 2>/dev/null`
    fi
  fi
  if [ -z "$JAVA_HOME" ]; then
        error_exit "Please set the JAVA_HOME variable in your environment, We need java(x64)! jdk8 or later is better!"
  fi
fi
# 脚本参数的默认值
export SERVER="nacos-server"
export MODE="cluster"
export FUNCTION_MODE="all"
export MEMBER_LIST=""
export EMBEDDED_STORAGE=""
while getopts ":m:f:s:c:p:" opt
do
    case $opt in
        m)
            MODE=$OPTARG;;
        f)
            FUNCTION_MODE=$OPTARG;;
        s)
            SERVER=$OPTARG;;
        c)
            MEMBER_LIST=$OPTARG;;
        p)
            EMBEDDED_STORAGE=$OPTARG;;
        ?)
        echo "Unknown parameter"
        exit 1;;
    esac
done

export JAVA_HOME
export JAVA="$JAVA_HOME/bin/java"
export BASE_DIR=`cd $(dirname $0)/..; pwd`
export CUSTOM_SEARCH_LOCATIONS=file:${BASE_DIR}/conf/

#===========================================================================================
# JVM Configuration
#===========================================================================================
if [[ "${MODE}" == "standalone" ]]; then
		# 单机模式默认占用512m内存
    JAVA_OPT="${JAVA_OPT} -Xms512m -Xmx512m -Xmn256m"
    JAVA_OPT="${JAVA_OPT} -Dnacos.standalone=true"
else
    if [[ "${EMBEDDED_STORAGE}" == "embedded" ]]; then
        JAVA_OPT="${JAVA_OPT} -DembeddedStorage=true"
    fi
    # 非单机模式占用2G内存
    JAVA_OPT="${JAVA_OPT} -server -Xms2g -Xmx2g -Xmn1g -XX:MetaspaceSize=128m -XX:MaxMetaspaceSize=320m"
    JAVA_OPT="${JAVA_OPT} -XX:-OmitStackTraceInFastThrow -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=${BASE_DIR}/logs/java_heapdump.hprof"
    JAVA_OPT="${JAVA_OPT} -XX:-UseLargePages"

fi
# 设置功能模式
if [[ "${FUNCTION_MODE}" == "config" ]]; then
    JAVA_OPT="${JAVA_OPT} -Dnacos.functionMode=config"
elif [[ "${FUNCTION_MODE}" == "naming" ]]; then
    JAVA_OPT="${JAVA_OPT} -Dnacos.functionMode=naming"
fi
# 设置集群成员列表
JAVA_OPT="${JAVA_OPT} -Dnacos.member.list=${MEMBER_LIST}"

# 设置GC启动参数
JAVA_MAJOR_VERSION=$($JAVA -version 2>&1 | sed -E -n 's/.* version "([0-9]*).*$/\1/p')
if [[ "$JAVA_MAJOR_VERSION" -ge "9" ]] ; then
  JAVA_OPT="${JAVA_OPT} -Xlog:gc*:file=${BASE_DIR}/logs/nacos_gc.log:time,tags:filecount=10,filesize=102400"
else
  JAVA_OPT_EXT_FIX="-Djava.ext.dirs=${JAVA_HOME}/jre/lib/ext:${JAVA_HOME}/lib/ext"
  JAVA_OPT="${JAVA_OPT} -Xloggc:${BASE_DIR}/logs/nacos_gc.log -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M"
fi
# 设置插件目录、nacos主目录、日志文件位置、spring附加配置文件参数
JAVA_OPT="${JAVA_OPT} -Dloader.path=${BASE_DIR}/plugins/health,${BASE_DIR}/plugins/cmdb,${BASE_DIR}/plugins/selector"
JAVA_OPT="${JAVA_OPT} -Dnacos.home=${BASE_DIR}"
JAVA_OPT="${JAVA_OPT} -jar ${BASE_DIR}/target/${SERVER}.jar"
JAVA_OPT="${JAVA_OPT} ${JAVA_OPT_EXT}"
JAVA_OPT="${JAVA_OPT} --spring.config.additional-location=${CUSTOM_SEARCH_LOCATIONS}"
JAVA_OPT="${JAVA_OPT} --logging.config=${BASE_DIR}/conf/nacos-logback.xml"
JAVA_OPT="${JAVA_OPT} --server.max-http-header-size=524288"
# 如果日志目录不存在创建日志目录
if [ ! -d "${BASE_DIR}/logs" ]; then
  mkdir ${BASE_DIR}/logs
fi

echo "$JAVA $JAVA_OPT_EXT_FIX ${JAVA_OPT}"
# 输出启动模式日志
if [[ "${MODE}" == "standalone" ]]; then
    echo "nacos is starting with standalone"
else
    echo "nacos is starting with cluster"
fi

# check the start.out log output file
if [ ! -f "${BASE_DIR}/logs/start.out" ]; then
  touch "${BASE_DIR}/logs/start.out"
fi
# start
echo "$JAVA $JAVA_OPT_EXT_FIX ${JAVA_OPT}" > ${BASE_DIR}/logs/start.out 2>&1 &

if [[ "$JAVA_OPT_EXT_FIX" == "" ]]; then
	#后台运行模式调用java命令
  nohup "$JAVA" ${JAVA_OPT} nacos.nacos >> ${BASE_DIR}/logs/start.out 2>&1 &
else
	#后台运行模式调用java命令
  nohup "$JAVA" "$JAVA_OPT_EXT_FIX" ${JAVA_OPT} nacos.nacos >> ${BASE_DIR}/logs/start.out 2>&1 &
fi

echo "nacos is starting，you can check the ${BASE_DIR}/logs/start.out"