title: nifi.sh 脚本解读
date: 2020-05-21
categories:

  • Apache NIFI
    tags:
  • Apache NIFI
    author: 张诚
    location: BeiJing
    publish: true
    sticky:

整个脚本分为三部分，第一部分是确定NIFI各个路径 目录的确定，设置环境变量，第二部分是方法区。第三部分是脚本逻辑代码的入口，初略的根据传参不同区执行不同的方法。以下脚本有详细注释：

  1. #!/bin/sh
  3. # ==========================
  4. # 1、查找文件的路径 start
  5. # ==========================
  7. # 由于MacOS X、FreeBSD和其他一些系统缺少gnu readlink，我们使用了基于以下StackOverflow注释http://stackoverflow.com/a/1116890/888876的更可移植的方法
  9. ## 特殊变量 当前脚本的文件名
  10. TARGET_FILE=$0
  11. #跳转到当前脚本所在的目录
  12. cd $(dirname $TARGET_FILE)
  13. ## TARGET_FILE=nifi.sh
  14. TARGET_FILE=$(basename $TARGET_FILE)
  16. ## 遍历(可能的)符号链接链   -L filename，判断文件是否问链接文件
  17. while [ -L "$TARGET_FILE" ]
  18. do
  19.     TARGET_FILE=$(readlink $TARGET_FILE)
  20.     cd $(dirname $TARGET_FILE)
  21.     TARGET_FILE=$(basename $TARGET_FILE)
  22. done
  25. # pwd -P  显示出实际路径，而非使用连接（link）路径。
  26. PHYS_DIR=$(pwd -P)
  27. # 脚本所在目录
  28. SCRIPT_DIR=$PHYS_DIR
  29. PROGNAME=$(basename "$0")
  30. # ==========================
  31. # 查找文件的路径 end
  32. # ==========================
  34. # 执行nifi-env.sh  设置了NIFI的目录环境变量
  35. . "${SCRIPT_DIR}/nifi-env.sh"
  37. # ==========================
  38. #/2、方法区 start
  39. # ==========================
  41. warn() {
  42.     echo "${PROGNAME}: $*"
  43. }
  45. die() {
  46.     warn "$*"
  47.     exit 1
  48. }
  50. # 检测特殊的操作系统，然后做一些特殊操作
  51. detectOS() {
  52.     # Cygwin是一个在windows平台上运行的类UNIX模拟环境
  53.     cygwin=false;
  54.     # AIX，是IBM专有的UNIX操作系统
  55.     aix=false;
  56.     # AS400是IBM早期推出的商用小型机
  57.     os400=false;
  58.     # Darwin是由苹果电脑于2000年所释出的一个开放原始码操作系统
  59.     darwin=false;
  60.     case "$(uname)" in
  61.         CYGWIN*)
  62.             cygwin=true
  63.             ;;
  64.         AIX*)
  65.             aix=true
  66.             ;;
  67.         OS400*)
  68.             os400=true
  69.             ;;
  70.         Darwin)
  71.             darwin=true
  72.             ;;
  73.     esac
  74.     # For AIX, set an environment variable
  75.     if ${aix}; then
  76.          export LDR_CNTRL=MAXDATA=0xB0000000@DSA
  77.          echo ${LDR_CNTRL}
  78.     fi
  79.     # In addition to those, go around the linux space and query the widely
  80.     # adopted /etc/os-release to detect linux variants
  81.     if [ -f /etc/os-release ]; then
  82.         . /etc/os-release
  83.     fi
  84. }
  86. unlimitFD() {
  87.     # Use the maximum available, or set MAX_FD != -1 to use that
  88.     # 判断 ${MAX_FD}有没有被赋值 条件成立则没有赋值
  89.     if [ "x${MAX_FD}" = "x" ]; then
  90.         MAX_FD="maximum"
  91.     fi
  93.     # 如果可能的话，提升文件描述符的最大数量
  94.     if [ "${os400}" = "false" ] && [ "${cygwin}" = "false" ]; then
  95.         MAX_FD_LIMIT=$(ulimit -H -n)
  96.         if [ "${MAX_FD_LIMIT}" != 'unlimited' ]; then
  97.             if [ $? -eq 0 ]; then
  98.                 if [ "${MAX_FD}" = "maximum" -o "${MAX_FD}" = "max" ]; then
  99.                     # use the system max
  100.                     MAX_FD="${MAX_FD_LIMIT}"
  101.                 fi
  103.                 ulimit -n ${MAX_FD} > /dev/null
  104.                 # echo "ulimit -n" `ulimit -n`
  105.                 if [ $? -ne 0 ]; then
  106.                     warn "Could not set maximum file descriptor limit: ${MAX_FD}"
  107.                 fi
  108.             else
  109.                 warn "Could not query system maximum file descriptor limit: ${MAX_FD_LIMIT}"
  110.             fi
  111.         fi
  112.     fi
  113. }
  116. # 找到要执行的JVM
  117. locateJava() {
  118.     # 设置Java虚拟机
  119.     if $cygwin ; then
  120.         [ -n "${JAVA}" ] && JAVA=$(cygpath --unix "${JAVA}")
  121.         [ -n "${JAVA_HOME}" ] && JAVA_HOME=$(cygpath --unix "${JAVA_HOME}")
  122.     fi
  124.     if [ "x${JAVA}" = "x" ] && [ -r /etc/gentoo-release ] ; then
  125.         JAVA_HOME=$(java-config --jre-home)
  126.     fi
  127.     if [ "x${JAVA}" = "x" ]; then
  128.         if [ "x${JAVA_HOME}" != "x" ]; then
  129.             if [ ! -d "${JAVA_HOME}" ]; then
  130.                 die "JAVA_HOME is not valid: ${JAVA_HOME}"
  131.             fi
  132.             JAVA="${JAVA_HOME}/bin/java"
  133.         else
  134.             warn "JAVA_HOME not set; results may vary"
  135.             JAVA=$(type java)
  136.             JAVA=$(expr "${JAVA}" : '.* \(/.*\)$')
  137.             if [ "x${JAVA}" = "x" ]; then
  138.                 die "java command not found"
  139.             fi
  140.         fi
  141.     fi
  142.     # 如果命令是 env, tools.jar classes.jar也加到 classpath
  143.     if [ "$1" = "env" ]; then
  144.         [ "x${TOOLS_JAR}" =  "x" ] && [ -n "${JAVA_HOME}" ] && TOOLS_JAR=$(find -H "${JAVA_HOME}" -name "tools.jar")
  145.         [ "x${TOOLS_JAR}" =  "x" ] && [ -n "${JAVA_HOME}" ] && TOOLS_JAR=$(find -H "${JAVA_HOME}" -name "classes.jar")
  146.         if [ "x${TOOLS_JAR}" =  "x" ]; then
  147.              warn "Could not locate tools.jar or classes.jar. Please set manually to avail all command features."
  148.         fi
  149.     fi
  151. }
  152. # 初始化 
  153. init() {
  154.     # 确定是否需要执行特殊的操作系统处理
  155.     detectOS
  157.     # 如果可能的话，不限制文件描述符的数量
  158.     unlimitFD
  160.     # 找到要执行的JVM
  161.     locateJava "$1"
  162. }
  164. # 将nifi安装为service
  165. install() {
  166.     detectOS
  168.     if [ "${darwin}" = "true"  ] || [ "${cygwin}" = "true" ]; then
  169.         echo 'Installing Apache NiFi as a service is not supported on OS X or Cygwin.'
  170.         exit 1
  171.     fi
  173.     SVC_NAME=nifi
  174.     if [ "x$2" != "x" ] ; then
  175.         SVC_NAME=$2
  176.     fi
  178.     # since systemd seems to honour /etc/init.d we don't still create native systemd services
  179.     # yet...
  180.     initd_dir='/etc/init.d'
  181.     SVC_FILE="${initd_dir}/${SVC_NAME}"
  183.     if [ ! -w  "${initd_dir}" ]; then
  184.         echo "Current user does not have write permissions to ${initd_dir}. Cannot install NiFi as a service."
  185.         exit 1
  186.     fi
  188. # Create the init script, overwriting anything currently present
  189. cat <<SERVICEDESCRIPTOR > ${SVC_FILE}
  190. #!/bin/sh
  192. #
  193. #    Licensed to the Apache Software Foundation (ASF) under one or more
  194. #    contributor license agreements.  See the NOTICE file distributed with
  195. #    this work for additional information regarding copyright ownership.
  196. #    The ASF licenses this file to You under the Apache License, Version 2.0
  197. #    (the "License"); you may not use this file except in compliance with
  198. #    the License.  You may obtain a copy of the License at
  199. #
  200. #       http://www.apache.org/licenses/LICENSE-2.0
  201. #
  202. #    Unless required by applicable law or agreed to in writing, software
  203. #    distributed under the License is distributed on an "AS IS" BASIS,
  204. #    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  205. #    See the License for the specific language governing permissions and
  206. #    limitations under the License.
  207. #
  208. # chkconfig: 2345 20 80
  209. # description: Apache NiFi is a dataflow system based on the principles of Flow-Based Programming.
  210. #
  212. # Make use of the configured NIFI_HOME directory and pass service requests to the nifi.sh executable
  213. NIFI_HOME=${NIFI_HOME}
  214. bin_dir=\${NIFI_HOME}/bin
  215. nifi_executable=\${bin_dir}/nifi.sh
  217. \${nifi_executable} "\$@"
  218. SERVICEDESCRIPTOR
  220.     if [ ! -f "${SVC_FILE}" ]; then
  221.         echo "Could not create service file ${SVC_FILE}"
  222.         exit 1
  223.     fi
  225.     # Provide the user execute access on the file
  226.     chmod u+x ${SVC_FILE}
  229.     # If SLES or OpenSuse...
  230.     if [ "${ID}" = "opensuse" ] || [ "${ID}" = "sles" ]; then
  231.         rm -f "/etc/rc.d/rc2.d/S65${SVC_NAME}"
  232.         ln -s "/etc/init.d/${SVC_NAME}" "/etc/rc.d/rc2.d/S65${SVC_NAME}" || { echo "Could not create link /etc/rc.d/rc2.d/S65${SVC_NAME}"; exit 1; }
  233.         rm -f "/etc/rc.d/rc2.d/K65${SVC_NAME}"
  234.         ln -s "/etc/init.d/${SVC_NAME}" "/etc/rc.d/rc2.d/K65${SVC_NAME}" || { echo "Could not create link /etc/rc.d/rc2.d/K65${SVC_NAME}"; exit 1; }
  235.         echo "Service ${SVC_NAME} installed"
  236.     # Anything other fallback to the old approach
  237.     else
  238.         rm -f "/etc/rc2.d/S65${SVC_NAME}"
  239.         ln -s "/etc/init.d/${SVC_NAME}" "/etc/rc2.d/S65${SVC_NAME}" || { echo "Could not create link /etc/rc2.d/S65${SVC_NAME}"; exit 1; }
  240.         rm -f "/etc/rc2.d/K65${SVC_NAME}"
  241.         ln -s "/etc/init.d/${SVC_NAME}" "/etc/rc2.d/K65${SVC_NAME}" || { echo "Could not create link /etc/rc2.d/K65${SVC_NAME}"; exit 1; }
  242.         echo "Service ${SVC_NAME} installed"
  243.     fi
  244. }
  246. run() {
  247.     BOOTSTRAP_CONF_DIR="${NIFI_HOME}/conf"
  248.     BOOTSTRAP_CONF="${BOOTSTRAP_CONF_DIR}/bootstrap.conf";
  249.     BOOTSTRAP_LIBS="${NIFI_HOME}/lib/bootstrap/*"
  251.     # 运行NiFi时使用的用户名。此值将在Windows上被忽略。在bootstrap.conf中 run.as= 配置
  252.     run_as_user=$(grep '^\s*run.as' "${BOOTSTRAP_CONF}" | cut -d'=' -f2)
  253.     # 如果以用户身份运行与启动流程相同，则忽略此配置
  254.     if [ "${run_as_user}" = "$(whoami)" ]; then
  255.         unset run_as_user
  256.     fi
  258.     if $cygwin; then
  259.         if [ -n "${run_as_user}" ]; then
  260.             echo "The run.as option is not supported in a Cygwin environment. Exiting."
  261.             exit 1
  262.         fi;
  264.         NIFI_HOME=$(cygpath --path --windows "${NIFI_HOME}")
  265.         NIFI_LOG_DIR=$(cygpath --path --windows "${NIFI_LOG_DIR}")
  266.         NIFI_PID_DIR=$(cygpath --path --windows "${NIFI_PID_DIR}")
  267.         BOOTSTRAP_CONF=$(cygpath --path --windows "${BOOTSTRAP_CONF}")
  268.         BOOTSTRAP_CONF_DIR=$(cygpath --path --windows "${BOOTSTRAP_CONF_DIR}")
  269.         BOOTSTRAP_LIBS=$(cygpath --path --windows "${BOOTSTRAP_LIBS}")
  270.         BOOTSTRAP_CLASSPATH="${BOOTSTRAP_CONF_DIR};${BOOTSTRAP_LIBS}"
  271.         if [ -n "${TOOLS_JAR}" ]; then
  272.             TOOLS_JAR=$(cygpath --path --windows "${TOOLS_JAR}")
  273.             BOOTSTRAP_CLASSPATH="${TOOLS_JAR};${BOOTSTRAP_CLASSPATH}"
  274.         fi
  275.     else
  276.         if [ -n "${run_as_user}" ]; then
  277.             if ! id -u "${run_as_user}" >/dev/null 2>&1; then
  278.                 echo "The specified run.as user ${run_as_user} does not exist. Exiting."
  279.                 exit 1
  280.             fi
  281.         fi;
  282.         BOOTSTRAP_CLASSPATH="${BOOTSTRAP_CONF_DIR}:${BOOTSTRAP_LIBS}"
  283.         if [ -n "${TOOLS_JAR}" ]; then
  284.             BOOTSTRAP_CLASSPATH="${TOOLS_JAR}:${BOOTSTRAP_CLASSPATH}"
  285.         fi
  286.     fi
  288.     echo
  289.     echo "Java home: ${JAVA_HOME}"
  290.     echo "NiFi home: ${NIFI_HOME}"
  291.     echo
  292.     echo "Bootstrap Config File: ${BOOTSTRAP_CONF}"
  293.     echo
  295.     #在后台运行'start'，因为进程将继续运行，监视NiFi。所有其他命令都将很快终止，所以要等待它们
  297.     #设置目录的参数
  298.     # java程序启动参数 -D 在System类中通过getProperties()得到的一串系统属性
  299.     BOOTSTRAP_LOG_PARAMS="-Dorg.apache.nifi.bootstrap.config.log.dir='${NIFI_LOG_DIR}'"
  300.     BOOTSTRAP_PID_PARAMS="-Dorg.apache.nifi.bootstrap.config.pid.dir='${NIFI_PID_DIR}'"
  301.     BOOTSTRAP_CONF_PARAMS="-Dorg.apache.nifi.bootstrap.config.file='${BOOTSTRAP_CONF}'"
  303.     # 去掉一下注釋就允许调试NIFI进程 (或者在bootstrap.conf中取消注释)
  304.     #BOOTSTRAP_DEBUG_PARAMS="-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8000"
  306.     BOOTSTRAP_DIR_PARAMS="${BOOTSTRAP_LOG_PARAMS} ${BOOTSTRAP_PID_PARAMS} ${BOOTSTRAP_CONF_PARAMS}"
  308.     run_nifi_cmd="'${JAVA}' -cp '${BOOTSTRAP_CLASSPATH}' -Xms12m -Xmx24m ${BOOTSTRAP_DIR_PARAMS} ${BOOTSTRAP_DEBUG_PARAMS} ${BOOTSTRAP_JAVA_OPTS} org.apache.nifi.bootstrap.RunNiFi $@"
  310.     if [ -n "${run_as_user}" ]; then
  311.       # 为运行提供SCRIPT_DIR并执行ni -env。
  312.       run_nifi_cmd="sudo -u ${run_as_user} sh -c \"SCRIPT_DIR='${SCRIPT_DIR}' && . '${SCRIPT_DIR}/nifi-env.sh' && ${run_nifi_cmd}\""
  313.     fi
  315.     if [ "$1" = "run" ]; then
  316.       # 使用exec将PID切换到RunNiFi java进程，而不是将其作为子进程( 前台运行nifi，Ctrl-C就停止NIFI)
  317.       # exec命令 用于调用并执行指令的命令。exec命令通常用在shell脚本程序中，可以调用其他的命令。如果在当前终端中使用命令，则当指定的命令执行完毕后会立即退出终端。
  318.       run_nifi_cmd="exec ${run_nifi_cmd}"
  319.     fi
  320.     # Linux eval命令用于重新运算求出参数的内容。
  321.     # eval可读取一连串的参数，然后再依参数本身的特性来执行。
  322.     if [ "$1" = "start" ]; then
  323.         ( eval "cd ${NIFI_HOME} && ${run_nifi_cmd}" & )> /dev/null 1>&-
  324.     else
  325.         eval "cd ${NIFI_HOME} && ${run_nifi_cmd}"
  326.     fi
  327.     EXIT_STATUS=$?
  329.    # 稍等(3秒)，等待日志记录完成，然后回显新行。
  330.    # 我们这样做是为了避免在运行命令后，日志在控制台被吐出来，然后返回给用户
  331.     sleep 3
  332.     echo
  333. }
  335. main() {
  336.     init "$1"
  337.     run "$@"
  338. }
  340. # ==========================
  341. # 方法区 end
  342. # ==========================
  344. # ==========================
  345. # 3、入口 start
  346. # ==========================
  348. # 判断 $1 第一个参数是什么 
  349. # 其中install 将nifi安装为service 
  350. # start 启动
  351. # stop 停止
  352. # run
  353. # status 
  354. # dump
  355. # env
  356. # restart 重启
  358. # $@ 传全部参数
  359. case "$1" in
  360.     install)
  361.         install "$@"
  362.         ;;
  363.     start|stop|run|status|dump|env)
  364.         main "$@"
  365.         ;;
  366.     restart)
  367.         init
  368.         run "stop"
  369.         run "start"
  370.         ;;
  371.     *)
  372.         echo "Usage nifi {start|stop|run|restart|status|dump|install}"
  373.         ;;
  374. esac

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nifi-sh - 图1