Jan Gehring > Rex-0.55.1 > Rex::Commands::Run

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Module Version: 0.55.1   Source  

NAME ^

Rex::Commands::Run - Execute a remote command

DESCRIPTION ^

With this module you can run a command.

SYNOPSIS ^

 my $output = run "ls -l";
 sudo "id";

EXPORTED FUNCTIONS ^

run($command [, $callback]) =item run($command_description, command => $command, %options)

This function will execute the given command and returns the output. In scalar context it returns the raw output as is, and in list context it returns the list of output lines. The exit value of the command is stored in the $? variable.

 task "uptime", "server01", sub {
   say run "uptime";
   run "uptime", sub {
     my ($stdout, $stderr) = @_;
     my $server = Rex::get_current_connection()->{server};
     say "[$server] $stdout\n";
   };
 };

Supported options are:

  cwd           => $path
    sets the working directory of the executed command to $path
  only_if       => $condition_command
    executes the command only if $condition_command completes successfully
  unless        => $condition_command
    executes the command unless $condition_command completes successfully
  only_notified => TRUE
    queues the command, to be executed upon notification (see below)
  env           => { var1 => $value1, ..., varN => $valueN }
    sets environment variables in the environment of the command

Examples:

If you only want to run a command in special cases, you can queue the command and notify it when you want to run it.

 task "prepare", sub {
   run "extract-something",
     command     => "tar -C /foo -xzf /tmp/foo.tgz",
     only_notified => TRUE;

   # some code ...

   notify "run", "extract-something";  # now the command gets executed
 };

If you only want to run a command if an other command succeed or fail, you can use only_if or unless option.

 run "some-command",
   only_if => "ps -ef | grep -q httpd";   # only run if httpd is running

 run "some-other-command",
   unless => "ps -ef | grep -q httpd";    # only run if httpd is not running

If you want to set custom environment variables you can do this like this:

 run "my_command",

    env => {
     env_var_1 => "the value for 1",
     env_var_2 => "the value for 2",
   };

If you want to end the command upon receiving a certain output: run "my_command", end_if_matched => qr/PATTERN/;

can_run($command)

This function checks if a command is in the path or is available. You can specify multiple commands, the first command found will be returned.

 task "uptime", sub {
   if( my $cmd = can_run("uptime", "downtime") ) {
     say run $cmd;
   }
 };
sudo

Run a command with sudo. Define the password for sudo with sudo_password.

You can use this function to run one command with sudo privileges or to turn on sudo globally.

 user "unprivuser";
 sudo_password "f00b4r";
 sudo -on;  # turn sudo globally on

 task prepare => sub {
   install "apache2";
   file "/etc/ntp.conf",
     source => "files/etc/ntp.conf",
     owner  => "root",
     mode  => 640;
 };

Or, if you don't turning sudo globally on.

 task prepare => sub {
   file "/tmp/foo.txt",
     content => "this file was written without sudo privileges\n";

   # everything in this section will be executed with sudo privileges
   sudo sub {
     install "apache2";
     file "/tmp/foo2.txt",
       content => "this file was written with sudo privileges\n";
   };
 };

Run only one command within sudo.

 task "eth1-down", sub {
  sudo "ifconfig eth1 down";
 };
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