我有一个 perl 脚本,在其中我想在实际执行 ssh 之前首先检查是否可以 ssh 进入服务器。因此,如果可以 ssh,则继续 ssh 进入该服务器,否则适当处理此异常。
所以我有这个脚本,它遍历一个包含数据库列表的文本文件,并尝试 ssh 进入每个服务器以执行 bash 命令来检查服务器是否正在执行 MySQL SST:
#!/usr/bin/perl -w
use strict;
use warnings;
use 5.010;
use DBI;
use Encode;
use IO::File;
use JSON;
use utf8;
BEGIN {
binmode STDERR, ':utf8';
binmode STDIN, ':utf8';
binmode STDOUT, ':utf8';
}
my $time = localtime();
my $file = '/opt/db-servers/db.txt';
open my $info, $file or die "Could not open $file: $!";
while( my $hostname = <$info>) {
chomp( $hostname );
my $xtrabk_check = `ssh $hostname ps -ef |grep mysql | grep wsrep_sst_xtrabackup-v2`;
my $role_check = `ssh $hostname ps -ef |grep mysql | grep donor`;
my $error_log = `ssh $hostname ps -ef |grep mysql`;
if ( $xtrabk_check ne "" ){
if ( $role_check ne "" ){
my $cmd ="curl -vs -o /dev/null -X POST --data-urlencode 'payload={\"channel\": \"#db-wsrep-status-log\", \"username\": \"db-wsrep-status-log\", \"text\": \"$time: $hostname: --role Donor \n```$error_log```\", \"icon_emoji\": \":scorpion:\"}' 2>&1 /dev/null https://hooks.slack.com/services/GVadasdd/B6LSMF5GV/BIApnzoIldfdsrw343wf";
system($cmd);
}
else {
my $cmd ="curl -vs -o /dev/null -X POST --data-urlencode 'payload={\"channel\": \"#db-wsrep-status-log\", \"username\": \"db-wsrep-status-log\", \"text\": \"$time: $hostname: State transfer in progress, setting sleep higher mysqld \n```$error_log```\", \"icon_emoji\": \":scorpion:\"}' 2>&1 https://hooks.slack.com/services/GVadasdd/B6LSMF5GV/BIApnzoIldfdsrw343wf";
system($cmd);
}
}
}
close $info;
因此,可能在执行下面的三行之前,我希望能够知道该服务器是否已关闭(因此无法 ssh 进入它)(然后使用以下命令 ssh 进入它):
my $xtrabk_check = `ssh $hostname ps -ef |grep mysql | grep wsrep_sst_xtrabackup-v2`;
my $role_check = `ssh $hostname ps -ef |grep mysql | grep donor`;
my $error_log = `ssh $hostname ps -ef |grep mysql`;
我怎样才能实现这一目标?顺便说一句,slack URL 已被更改,因此存在安全问题。
我在下面添加了建议的代码,但似乎仍然不起作用:
...
while( my $hostname = <$info>) {
chomp( $hostname );
my $ssh_ping = `$ssh_cmd\'@\'$hostname true`;
if ( `$ssh_ping true`){
my $xtrabk_check = `ssh $hostname ps -ef |grep mysql | grep wsrep_sst_xtrabackup-v2`;
my $role_check = `ssh $hostname ps -ef |grep mysql | grep donor`;
my $error_log = `ssh $hostname ps -ef |grep mysql`;
if ( $xtrabk_check ne "" ){
if ( $role_check ne "" ){
my $cmd ="curl -vs -o /dev/null -X POST --data-urlencode 'payload={\"channel\": \"#db-wsrep-status-log\", \"username\": \"db-wsrep-status-log\", \"text\": \"$time: $hostname: --role Donor \n```$error_log```\", \"icon_emoji\": \":scorpion:\"}' 2>&1 /dev/null https://hooks.slack.com/services/GVadasdd/B6LSMF5GV/BIApnzoIldfdsrw343wf";
system($cmd);
}
else {
my $cmd ="curl -vs -o /dev/null -X POST --data-urlencode 'payload={\"channel\": \"#db-wsrep-status-log\", \"username\": \"db-wsrep-status-log\", \"text\": \"$time: $hostname: State transfer in progress, setting sleep higher mysqld \n```$error_log```\", \"icon_emoji\": \":scorpion:\"}' 2>&1 https://hooks.slack.com/services/GVadasdd/B6LSMF5GV/BIApnzoIldfdsrw343wf";
system($cmd);
}
}
} #end $ssh_ping if
} #end while
答案1
你可以这样做:
`ssh $hostname true`;
if ($? == 0) {
...;
} else {
die "ssh failed";
}