NAME
rex - execute tasks defined in a Rexfile
DESCRIPTION
The "rex" script can be used to execute tasks defined in a Rexfile from the command line.
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
-Ta List all tasks, including hidden
-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";
};
TAB COMPLETION
Tab completion scripts are provided for Bash and Zsh in the share <https://metacpan.org/release/Rex/source/share>; directory. They provide completions for the available CLI options, hosts, groups, environments and tasks.