NAME

       (R)?ex - (Remote)? Execution

DESCRIPTION

       Rex is a command line tool which executes commands on remote servers.  Define tasks in
       Perl and execute them on remote servers or groups of servers.

       Rex can be used to:

       - Deploy web applications to servers sequentially or in parallel.
       - Automate common tasks.
       - Provision servers using Rex's builtin tools.

SYNOPSIS

           bash# rex -h                      # Show usage
           bash# rex -T                      # List tasks
           bash# rex uname                   # Run the 'uname' task
           bash# rex -H server[01..10] uname # Run the 'uname' task on all the specified hosts
           bash# rex -G production uname     # Run 'uname' on hosts on the 'production' hostgroup
           bash# rex deploy --gracefully     # Pass '--gracefully' to the 'deploy' task

USAGE

           rex [<options>] [-H <host>] [-G <group>] <task> [<task-options>]
           rex -T[m|y|v] [<string>]

           -b     Run batch
           -e     Run the given code fragment
           -E     Execute a task on the given environment
           -G|-g  Execute a task on the given server groups
           -H     Execute a task on the given hosts (space delimited)
           -z     Execute a task on hosts from this command's output

           -K     Public key file for the ssh connection
           -P     Private key file for the ssh connection
           -p     Password for the ssh connection
           -u     Username for the ssh connection

           -d     Show debug output
           -ddd   Show more debug output (includes profiling output)
           -m     Monochrome output: no colors
           -o     Output format
           -q     Quiet mode: no log output
           -qw    Quiet mode: only output warnings and errors
           -Q     Really quiet: output nothing

           -T     List tasks
           -Tm    List tasks in machine-readable format
           -Tv    List tasks verbosely
           -Ty    List tasks in YAML format

           -c     Turn cache ON
           -C     Turn cache OFF
           -f     Use this file instead of Rexfile
           -F     Force: disregard lock file
           -h     Display this help message
           -M     Load this module instead of Rexfile
           -O     Pass additional options, like CMDB path
           -s     Use sudo for every command
           -S     Password for sudo
           -t     Number of threads to use (aka 'parallelism' param)
           -v     Display (R)?ex version

Rexfile

       When you run "rex" it reads the file "Rexfile" in the current working directory. A Rexfile
       consists of 2 major parts: Configuration and Task Definitions.

   Configuration
       Simple Authentication

           user "bruce";
           password "batman";
           pass_auth;

       Key Authentication

           private_key "/path/to/your/private/key.file";
           public_key "/path/to/your/public/key.file";

       Define Logging

           logging to_file => "rex.log";
           logging to_syslog => "local0";

       Group your servers

       Rex gives you the ability to define groups of servers. Groups can be defined the Rexfile:

           group "frontends" => "frontend01", "frontend02", "frontend03", "frontend04", "frontend[05..09]";

       Groups can also be defined in a server.ini file:

           [frontends]
           frontend[01..04]

   Other Configuration
           timeout 10;    # ssh timeout
           parallelism 2; # execute tasks in parallel

   Defining tasks
       A basic task looks like this:

           # task description
           desc "This task tells you how long since the server was rebooted";

           # task definition
           task "shortname", sub {
               say run "uptime";
           };

       You can also set a default server group:

           desc "This is a long description of a task";
           task "shortname", group => "frontends", sub {
               say run "uptime";
           };