SaltStack 安装脚本学习心得

2023-10-18

字数统计: 1.9k字 | 阅读时长≈ 10分

原始脚本地址：bootstrap-salt

关于脚本开头 “-“ 说明

1 2	#!/bin/sh - # 说明：/bin/sh 后面的 "-" 表示选项结束，并禁用进一步的选项处理。- 后面的任何参数均被视为文件名和参数。"--" 等效于 "-"。

脚本开始添加 set 参数，如下所示

1 2	set -o nounset # 遇到空变量时报错退出，等同于 set -u set -e # 程序遇到退出码为非零时，结束退出脚本

脚本内部变量使用双下划线开头，如下所示

__ScriptVersion="2019.10.03"                # 脚本版本
__ScriptName="bootstrap-salt.sh"            # 脚本名称
__ScriptFullName="$0"                       # shell 脚本参数中，$0 表示程序名称，即执行脚本时输入脚本的名称
__ScriptArgs="$#"                           # 执行脚本时输入的所有参数列表

除了以上内容，还可自己添加其他的一些变量，用来获取系统版本，主机 IP，当前用户等等一些信息，用于打印出来提示用户

对脚本中使用到的变量进行说明，如下

#======================================================================================================================
# Environment variables taken into account.
#----------------------------------------------------------------------------------------------------------------------
# * BS_COLORS: If 0 disables colour support
# * BS_PIP_ALLOWED: If 1 enable pip based installations(if needed)
# * BS_PIP_ALL: If 1 enable all python packages to be installed via pip instead of apt, requires setting virtualenv
# * BS_VIRTUALENV_DIR: The virtualenv to install salt into (shouldn't exist yet)
# * BS_ECHO_DEBUG: If 1 enable debug echo which can also be set by -D
# * BS_SALT_ETC_DIR: Defaults to /etc/salt (Only tweak'able on git based installations)
# * BS_SALT_CACHE_DIR: Defaults to /var/cache/salt (Only tweak'able on git based installations)
# * BS_KEEP_TEMP_FILES: If 1, don't move temporary files, instead copy them
# * BS_FORCE_OVERWRITE: Force overriding copied files(config, init.d, etc)
# * BS_UPGRADE_SYS: If 1 and an option, upgrade system. Default 0.
# * BS_GENTOO_USE_BINHOST: If 1 add `--getbinpkg` to gentoo's emerge
# * BS_SALT_MASTER_ADDRESS: The IP or DNS name of the salt-master the minion should connect to
# * BS_SALT_GIT_CHECKOUT_DIR: The directory where to clone Salt on git installations
#======================================================================================================================

设置脚本中的真假值

1 2	BS_TRUE=1 BS_FALSE=0

设置脚本执行时的默认睡眠时间

1	__DEFAULT_SLEEP=3

修改颜色输出，使用函数的方式更方便调用

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: __detect_color_support
# DESCRIPTION: Try to detect color support.
#--------------------------------------------------------------------------------------------------------------------
_COLORS=${BS_COLORS:-$(tput colors 2>/dev/null || echo 0)}
__detect_color_support() {
    # shellcheck disable=SC2181
    if [ $? -eq 0 ] && [ "$_COLORS" -gt 2 ]; then
        RC='\033[1;31m'
        GC='\033[1;32m'
        BC='\033[1;34m'
        YC='\033[1;33m'
        EC='\033[0m'
    else
        RC=""
        GC=""
        BC=""
        YC=""
        EC=""
    fi
}

__detect_color_support

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: echoerr
# DESCRIPTION: 错误信息输出
#----------------------------------------------------------------------------------------------------------------------
echoerror() {
    printf "${RC} * ERROR${EC}: %s\\n" "$@" 1>&2;
}

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: echoinfo
# DESCRIPTION: 正常信息输出
#----------------------------------------------------------------------------------------------------------------------
echoinfo() {
    printf "${GC} * INFO${EC}: %s\\n" "$@";
}

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: echowarn
# DESCRIPTION: 告警信息输出.
#----------------------------------------------------------------------------------------------------------------------
echowarn() {
    printf "${YC} * WARN${EC}: %s\\n" "$@";
}

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: echodebug
# DESCRIPTION: 调试信息输出.
#----------------------------------------------------------------------------------------------------------------------
echodebug() {
    if [ "$_ECHO_DEBUG" -eq $BS_TRUE ]; then
        printf "${BC} * DEBUG${EC}: %s\\n" "$@";
    fi
}

脚本使用方法提示信息

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: __usage
# DESCRIPTION: Display usage information.
#--------------------------------------------------------------------------------------------------------------------
__usage() {
    cat << EOT
  Usage : ${__ScriptName} [options] <install-type> [install-type-args]
  Installation types:
    - stable Install latest stable release. This is the default
                          install type
    - stable [branch] Install latest version on a branch. Only supported
                          for packages available at repo.saltstack.com
...... 此处省略 N 行 ......
  Examples:
    - ${__ScriptName}
    - ${__ScriptName} stable
    - ${__ScriptName} stable 2017.7
...... 此处省略 N 行 ......
  Options:
    -h Display this message
    -v Display script version
    -n No colours
    -D Show debug output
...... 此处省略 N 行 ......
EOT

脚本中获取命令行参数的方法

while getopts ':hvnDc:g:Gyx:wk:s:MSNXCPFUKIA:i:Lp:dH:bflV:J:j:rR:aq' opt
do
  case "${opt}" in
    h ) __usage; exit 0 ;;
    v ) echo "$0 -- Version $__ScriptVersion"; exit 0 ;;
    n ) _COLORS=0; __detect_color_support ;;
    D ) _ECHO_DEBUG=$BS_TRUE ;;
    x ) _PY_EXE="$OPTARG" ;;
    y ) _INSTALL_PY="$BS_TRUE" ;;
...... 此处省略 N 行 ......
    \?) echo
         echoerror "Option does not exist : $OPTARG"
         __usage
         exit 1
         ;;
  esac 
done

shift $((OPTIND-1))

shell 脚本设置日志输出的方式

# 设置日志输出文件以及日志输出管道
LOGFILE="/tmp/$( echo "$__ScriptName" | sed s/.sh/.log/g )"
LOGPIPE="/tmp/$( echo "$__ScriptName" | sed s/.sh/.logpipe/g )"

# 删除残留的旧管道
rm "$LOGPIPE" 2>/dev/null

# 创建日志输出管道
# On FreeBSD we have to use mkfifo instead of mknod
if ! (mknod "$LOGPIPE" p >/dev/null 2>&1 || mkfifo "$LOGPIPE" >/dev/null 2>&1); then
    echoerror "Failed to create the named pipe required to log"
    exit 1
fi

# 将日志管道中的信息写入到日志文件中
tee < "$LOGPIPE" "$LOGFILE" &

# 关闭标准输出，然后将其重新打开并重定向到日志输出管道
exec 1>&-
exec 1>"$LOGPIPE"

# 关闭错误输出，然后将其重新打开并重定向到日志输出管道
exec 2>&-
exec 2>"$LOGPIPE"

清理脚本执行痕迹

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: __exit_cleanup
# DESCRIPTION: Cleanup any leftovers after script has ended
#
#
# http://www.unix.com/man-page/POSIX/1posix/trap/
#
# Signal Number Signal Name
# 1 SIGHUP
# 2 SIGINT
# 3 SIGQUIT
# 6 SIGABRT
# 9 SIGKILL
# 14 SIGALRM
# 15 SIGTERM
#----------------------------------------------------------------------------------------------------------------------

APT_ERR=$(mktemp /tmp/apt_error.XXXXXX)

__exit_cleanup() {
    EXIT_CODE=$?
    if [ "$ITYPE" = "git" ] && [ -d "${_SALT_GIT_CHECKOUT_DIR}" ]; then
        if [ $_KEEP_TEMP_FILES -eq $BS_FALSE ]; then
            # Clean up the checked out repository
            echodebug "Cleaning up the Salt Temporary Git Repository"
            # shellcheck disable=SC2164
            cd "${__SALT_GIT_CHECKOUT_PARENT_DIR}"
            rm -rf "${_SALT_GIT_CHECKOUT_DIR}"
        else
            echowarn "Not cleaning up the Salt Temporary git repository on request"
            echowarn "Note that if you intend to re-run this script using the git approach, you might encounter some issues"
        fi
    fi

    # Remove the logging pipe when the script exits
    if [ -p "$LOGPIPE" ]; then
        echodebug "Removing the logging pipe $LOGPIPE"
        rm -f "$LOGPIPE"
    fi

    # Remove the temporary apt error file when the script exits
    if [ -f "$APT_ERR" ]; then
        echodebug "Removing the temporary apt error file $APT_ERR"
        rm -f "$APT_ERR"
    fi

    # Kill tee when exiting, CentOS, at least requires this
    # shellcheck disable=SC2009
    TEE_PID=$(ps ax | grep tee | grep "$LOGFILE" | awk '{print $1}')
    [ "$TEE_PID" = "" ] && exit $EXIT_CODE
    echodebug "Killing logging pipe tee's with pid(s): $TEE_PID"

    # We need to trap errors since killing tee will cause a 127 errno
    # We also do this as late as possible so we don't "mis-catch" other errors
    __trap_errors() {
        echoinfo "Errors Trapped: $EXIT_CODE"
        # Exit with the "original" exit code, not the trapped code
        exit $EXIT_CODE
    }

    trap "__trap_errors" INT ABRT QUIT TERM
    # Now we're "good" to kill tee
    kill -s TERM "$TEE_PID"
    # In case the 127 errno is not triggered, exit with the "original" exit code
    exit $EXIT_CODE
}

trap "__exit_cleanup" EXIT INT

打印脚本信息

# Let's discover how we're being called
# shellcheck disable=SC2009
CALLER=$(ps -a -o pid,args | grep $$ | grep -v grep | tr -s ' ' | cut -d ' ' -f 3)

if [ "${CALLER}x" = "${0}x" ]; then
    CALLER="shell pipe"
fi



echoinfo "Running version: ${__ScriptVersion}"
echoinfo "Executed by: ${CALLER}"
echoinfo "Command line: '${__ScriptFullName} ${__ScriptArgs}'"
echowarn "Running the unstable version of ${__ScriptName}"

解析并检查命令行输入的参数，参数列表必须要上面 while 循环中使用 getops 获取到的

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: __check_unparsed_options
# DESCRIPTION: Checks the placed after the install arguments
#----------------------------------------------------------------------------------------------------------------------
__check_unparsed_options() {
    shellopts="$1"
    # grep alternative for SunOS
    if [ -f /usr/xpg4/bin/grep ]; then
        grep='/usr/xpg4/bin/grep'
    else
        grep='grep'
    fi

    unparsed_options=$( echo "$shellopts" | ${grep} -E '(^|[[:space:]])[-]+[[:alnum:]]' )
    if [ "$unparsed_options" != "" ]; then
        __usage
        echo
        echoerror "options are only allowed before install arguments"
        echo
        exit 1
    fi
}

# Define installation type
if [ "$#" -gt 0 ];then
    __check_unparsed_options "$*"
    ITYPE=$1
    shift
fi

获取当前执行用户的方式

# whoami alternative for SunOS
if [ -f /usr/xpg4/bin/id ]; then
    whoami='/usr/xpg4/bin/id -un'
else
    whoami='whoami'
fi

# Root permissions are required to run this script
if [ "$($whoami)" != "root" ]; then
    echoerror "Salt requires root privileges to install. Please re-run this script as root."
    exit 1
fi

获取硬件信息

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: __gather_hardware_info
# DESCRIPTION: Discover hardware information
#----------------------------------------------------------------------------------------------------------------------
__gather_hardware_info() {
    if [ -f /proc/cpuinfo ]; then
        CPU_VENDOR_ID=$(awk '/vendor_id|Processor/ {sub(/-.*$/,"",$3); print $3; exit}' /proc/cpuinfo )
    elif [ -f /usr/bin/kstat ]; then
        # SmartOS.
        # Solaris!?
        # This has only been tested for a GenuineIntel CPU
        CPU_VENDOR_ID=$(/usr/bin/kstat -p cpu_info:0:cpu_info0:vendor_id | awk '{print $2}')
    else
        CPU_VENDOR_ID=$( sysctl -n hw.model )
    fi

    # shellcheck disable=SC2034
    CPU_VENDOR_ID_L=$( echo "$CPU_VENDOR_ID" | tr '[:upper:]' '[:lower:]' )
    CPU_ARCH=$(uname -m 2>/dev/null || uname -p 2>/dev/null || echo "unknown")
    CPU_ARCH_L=$( echo "$CPU_ARCH" | tr '[:upper:]' '[:lower:]' )
}

__gather_hardware_info

获取系统信息

#--- FUNCTION -------------------------------------------------------------------------------------------------------
# NAME: __gather_os_info
# DESCRIPTION: Discover operating system information
#----------------------------------------------------------------------------------------------------------------------
__gather_os_info() {
    OS_NAME=$(uname -s 2>/dev/null)
    OS_NAME_L=$( echo "$OS_NAME" | tr '[:upper:]' '[:lower:]' )
    OS_VERSION=$(uname -r)
    # shellcheck disable=SC2034
    OS_VERSION_L=$( echo "$OS_VERSION" | tr '[:upper:]' '[:lower:]' )
}

__gather_os_info