在SIGINT时优雅地关闭ssh并退出net :: ssh :: perl

时间:2012-07-18 07:10:43

标签: perl ssh event-handling signals

我正在连接远程主机并执行一个不退出的命令(tail -f logfile)

我正在注册处理程序并将输出写入日志文件。 这工作正常 但我想在主程序上按Control + C,它应该停止远程机器上的命令并优雅地关闭ssh连接

所以我正在为SIGINT注册一个信号处理程序

需要我需要在子程序中添加的代码

以下代码位于从分叉子

调用的函数内
#!/ats/bin/perl

use Net::SSH::Perl;
use File::Path;
use Text::CSV_XS;

chomp ($progName = `basename $0`);

if (@ARGV != 1 ) {
        print "usage: perl $progName <tc_id>\n";
        exit;
}

$tc_id = shift;
$file = "config.prop";
$log_dir = "logs/";


#$SIG{INT}=\&close_write;

sub close_write
{
#-- write it to file
print "\nInside END block\n";
#open FH, ">$log_file";
#print $log_file;
#print FH @out;
#$thr->kill('INT');
#close $ssh->sock;
#undef $ssh;
exit 1;
}

# Read the configuration file and populate the Hash
$index = 0;
my $csv = Text::CSV_XS->new ({ binary => 1, eol => $/ });
 open my $io, "<", $file or die "$file: $!";
 while (my $row = $csv->getline ($io)) {
    next if (${$row}[0] =~ m/^#/);  #Ignore comments
    next if (${$row}[0] =~ m/^\s*$/);   #Ignore blank lines
    ($logHashArray->[$index]->{host}, $logHashArray->[$index]->{user}, $logHashArray->[$index]->{pass}, $logHashArray->[$index]->{cmd}, $logHashArray->[$index]->{log_file}) = @$row;
    $index++;
 }


# Append "/" at the end of the directory if it does not exist
unless ($log_dir =~ m/\/$/) {
        $log_dir = $log_dir . "/";
        print "LogDir: $log_dir\n";
        }
# Check if the log directory exists, if not, create it
if (-e $log_dir) {
        unless (-d $log_dir) {
                die "File exists but is not directory";
                }
        }
else {
        # don't forget to check mkdir's failure
        print "Directory $log_dir does not exist... Creating it\n";
        mkpath($log_dir, 0777) or die "Can't make directory: $!";
        }



foreach $logHash (@{$logHashArray}){
        #print "LogHash Index $logHash\n";
        $logHash->{log_file} = $tc_id . "_" . $logHash->{host} . "_" .$logHash->{log_file};
        $logHash->{cmd} = $logHash->{cmd} . " | tee /tmp/" . $logHash->{log_file};
        $logHash->{log_dir} = $log_dir;

        #$logHash->{thr}=threads->new(\&connect_get_logs, $logHash);

        $logHash->{pid} = fork();

        if ($logHash->{pid}){
            # Parent
            push(@childs, $logHash->{pid});
        }
        elsif ($pid == 0){
            # Child
            connect_get_logs($logHash);
        }
        else {
            die "couldn’t fork: $!\n";
            }

while (($key, $value) = each(%{$logHash})){
     print $key."=>".$value."\n";
}

}

#$SIG{INT}=\&close_write;
#$thr=threads->new(\&connect_get_logs, $logHash);

foreach (@childs) {
    waitpid($_, 0);
    }


#print "Waiting...";
#while(1) {sleep 1;}

#$thr->join;


sub connect_get_logs{

$SIG{INT}= sub {
        print "Inside INT block\n"; ### Need proper code here
        close $ssh->sock;
        undef $ssh;
        };

my $logHash = shift;

while (($key, $value) = each(%{$logHash})){
     print $key."=>".$value."\n";
}
my $stdout;
my $stderr;
my $exit;

#-- setup a new connection
print "Logging in to $logHash->{host}...";
my $ssh = Net::SSH::Perl->new($logHash->{host}, debug => 0, protocol => '2', options => ["PasswordAuthentication yes", "BatchMode yes",
                    "PubkeyAuthenticaion no", "RhostsAuthentication no", "RhostsRSAAuthentication no", "RSAAuthentication no", "DSAAuthentication no"]);

#-- authenticate
$ssh->login($logHash->{user}, $logHash->{pass});
print "Logged In\n";

#-- Create or Overwrite the log files
open LOG_FILE, ">", "$logHash->{log_dir}$logHash->{log_file}" or die $!;

#-- register a handler
$ssh->register_handler("stdout", sub {
        my($channel, $buffer) = @_;
        $str = $buffer->bytes;
        #push @out, $str;
        print LOG_FILE $str;
        #print $str;
});

#$SIG{INT}=\&close_write;

#-- execute the command
($stdout, $stderr, $exit) = $ssh->cmd($logHash->{cmd});

print "Error: $stderr";

}

以csv格式创建一个config.prop文件

host / ip,username,password,command(tail -F / full / path / to / logfile),要保存的文件名

5 个答案:

答案 0 :(得分:2)

诀窍是使用-t(或可能-tt)调用ssh。

默认情况下,ssh仅在远程计算机上为交互式登录shell分配pty(即,不在远程调用命令时)。 -t强制ssh分配pty,即使在执行远程命令时也是如此。你可以看到效果:

$ ssh starquake tty
not a tty

VS

$ ssh -t starquake tty
/dev/pts/1
Connection to starquake closed.

ssh apparently will pass on signals to the remote process连接到终端时,但不是。

答案 1 :(得分:0)

如果您知道对tail -f的调用的进程ID,则可以从命令行向其发送INT信号:

kill -s INT <pid>

您需要在主程序的$SIG{'INT'}中执行的操作是让它通过INT连接发送Net::SSH。不幸的是,我不知道该怎么做。

答案 2 :(得分:0)

$ SSH-&GT;登录(); #to登录ssh会话

$ ssh - &gt;关闭; #从ssh会话注销

享受。

答案 3 :(得分:0)

在这里,您可以看到使用SFTP而不是SSH连续读取远程文件的替代解决方案:sftp_tail.pl

远程sftp-server进程将在连接关闭时退出(例如,因为您按Ctrl-C),而无需您执行任何进一步操作。

答案 4 :(得分:-1)

在perl中登录,访问和关闭ssh会话的完整过程。

            my $host = 192.168.0.1;

            my $username = "example";

            my $passwd  = "example";

            my $ssh = Net::SSH::Expect->new(
            host => $host,
            user => $username,
            password => $passwd,
            timeout => 20,
            );
            $ssh->login();
            $ssh->exec("command_to_be_executed_in_ssh\r\n");
            $ssh ->close;