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命令未透過 SSH 執行

tag-icon • tag-icon bash ssh command
命令未透過 SSH 執行

我為課程製作了這個腳本。它透過 ssh 從腳本的參數在檔案中指定的多個遠端伺服器上執行命令：

#!/bin/bash

# The server file. Can be changed with the -f argument
SERVER_FILE='/vagrant/servers'

# The function to check if the chosen SERVER_FILE exists
filecheck() {
if [[ ! -e $SERVER_FILE ]]; then
  echo "The file $SERVER_FILE does not exist." >&2
  exit 1
fi
}

# The usage statement
usage() {
  echo "usage $0 -vsn -f FILE 'COMMAND'"
  echo "  -v Verbose mode"
  echo "  -s Run command as sudo on remote server"
  echo "  -n Dry run, commands not actually executed"
  echo "  -f FILE Selects a different file other than /vagrant/servers"
  exit 1
}

# The verbose mode text things
say() {
  if [[ $VERBOSE = 'true' ]]; then
    echo "$@"
  fi
}

# The ssh command
sshing() {
  ssh -o ConnectTimeout=2 $SERVER $@
}

# User executing the command should not be root
if [[ $UID -eq 0 ]]; then
  echo "You should not execute this script with sudo or as root" >&2
  echo "Use the -s argument if you want sudo powers" >&2
  exit 1
fi

# DRYMODE is sshing by Default
DRYMODE='sshing'

#check to see if file SERVER_FILE exists
filecheck

# The options for the script
while getopts vsnf: OPTION; do
  case $OPTION in
    v)
      echo "Verbose mode on"
      VERBOSE='true'
      ;;
    s)
      say "Sudo mode"
      SUDO='sudo'
      ;;
    n)
      say "Dry run mode"
      DRYMODE='echo'
      DRYRUN='DRY RUN: '
      echo "DRY RUN MODE ON: "
      echo
      ;;
    f)
      say "Different file mode"
      SERVER_FILE=${OPTARG}
      #check to see if file SERVER_FILE exists
      filecheck
      ;;
    *)
      usage
      ;;
  esac
done

echo

# shifts so that the options are removed from the list of arguments
shift $((OPTIND-1))

#Set a variable for the rest of the arguments, as a command
COMMAND="${@}"

# Checks if the user provided any arguments apart from the optinos
if [[ $# -eq 0 ]]; then
  usage
  exit 1
fi

# Executes the commands
for SERVER in $(cat ${SERVER_FILE}); do
  say "Executing ${COMMAND} on ${SERVER}:"
  $DRYMODE $DRYRUN $SUDO ${COMMAND} 2> /dev/null
  CMDEX=$?
  # if the exit status is 255, something is wrong with the server or is unreachable
  if [[ $CMDEX -eq 255 ]]; then
    echo "The server you're trying to reach does not exist or is unreachable. Aborting." >&2
    exit 1
  fi
  # if the exit status is non 0 and non 255, something is wrong with the command
  if [[ $CMDEX -ne 0 ]]; then
    echo "Invalid command ${COMMAND} or wrong syntax. Aborting." >&2
    exit 1
    # if the exit status is non 0 and non 255, something is wrong with the command
  fi
  say "Command ${COMMAND} executed successfuly."
done
exit 0

它非常適合簡單的命令（例如ls，ps，甚至adduser test），但如果我給它任何包含雙引號的命令，它就會中斷，除非我單引號整個命令。

現在我不知道這是否是我的程式碼中的錯誤或其他問題，但我無法通過此管道命令。

所以這個命令不起作用：

[vagrant@admin01 vagrant]$ ./run-everywhere.sh -sv 'echo 1 | passwd --stdin test4'

如果我用 \| 逃離管道它只是字面上將其寫為\|。這個其他指令也不起作用：

[vagrant@admin01 vagrant]$ ./run-everywhere.sh -sv 'echo "1" | sha256sum > file1'

編輯：

我發現管道無法工作的問題：如果命令需要 sudo 權限，我還必須在管道之後編寫 sudo 。這個是這樣運作的：

[vagrant@admin01 vagrant]$ ./run-everywhere.sh -sv 'echo 1 | sudo passwd --stdin test4'

但我仍然無法重定向。

答案1

嘗試這個：

sshing () {
  ssh -o ConnectTimeout=2 "$SERVER" "$@"
  # ................................^..^ crucial quotes
}
# ...
cmd="$*"
# ...
while read -r SERVER; do
  say "Executing ${COMMAND} on ${SERVER}:"
  $DRYMODE $DRYRUN $SUDO sh -c "${COMMAND}" 2> /dev/null
  # .....................11111.2..........2
  # 1. run with a shell to enable redirections and pipe
  # 2. crucial quotes
  # ...
done < "$SERVER_FILE"

使用 sudo 在 shell 中執行命令將允許整個管道以提升的權限執行。

另外，您應該改掉使用全大寫變數名的習慣。有一天，您會不小心覆蓋 PATH，然後想知道為什麼您的腳本被破壞了。

答案2

發現問題了。如果我使用 sudo 權限運行腳本來自行處理某些文件，它將在 root 的名稱和群組下創建文件，這意味著我對該文件沒有權限。

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