REX(1) User Contributed Perl Documentation REX(1)NAME
(R)?ex - (Remote)? Execution
DESCRIPTION
Rex is a tool to ease the execution of commands on multiple remote
servers. You can define small tasks, chain tasks to batches, link them
with servers or server groups, and execute them easily in your
terminal.
Command line options
-b Run batch
-e Run the give code fragment
-E Execute task on the given environment
-H Execute task on these hosts
-z Execute task on hosts from this command's output
-G|-g Execute task on these group
-u Username for the ssh connection
-p Password for the ssh connection
-P Private Keyfile for the ssh connection
-K Public Keyfile for the ssh connection
-T List all known tasks.
-Tm List all known tasks in "machine readable" format
-Ty List all known tasks in YAML format
-Tv List all known tasks with all information
-f Use this file instead of Rexfile
-h Display this help
-m Monochrome output. No colors
-M Load Module instead of Rexfile
-s Use sudo for every command
-S Password for sudo
-v Display (R)?ex Version
-F Force. Don't regard lock file
-d Debug
-dd More Debug (includes Profiling Output)
-o <module> Create a compatible output for the given module
-C Turn cache OFF
-c Turn cache ON
-q Quiet mode. No Logging output
-qw Quiet mode. Only output warnings and errors
-Q Really quiet. Output nothing.
-t Number of threads to use ('parallelism' parameter)
Rexfile
If you run rex it will read the file Rexfile in the current working
directory. A Rexfile consists of 3 major parts.
Authentication and Configuration
In that part you define the user and password you want to use to log
into your servers. You can even define timeouts or the paralellism of
task execution.
Simple Authentication
Define the user
user "<user>";
Define the password
password "<password>";
Set password authentication
pass_auth;
Key Authentication
Define Private Key
private_key "/path/to/your/private/key.file";
Define Public Key
public_key "/path/to/your/public/key.file";
Define Logging
Log to a file
logging to_file => "rex.log";
Log to syslog
logging to_syslog => "local0";
Other Configuration parameters
Define ssh timeout
timeout 10;
Define parallelism
parallelism 2;
Group your servers
Rex gives you the possibility to group your servers. One way is to do
it in code within the Rexfile. Another is to use a server.ini file in
the same directory as the Rexfile.
Code in the Rexfile
Rex gives you the possibility to group your servers. So you don't need
to type every servername multiple times.
group "frontends" => "frontend01", "frontend02", "frontend03", "frontend04";
You can even define ranges in the servernames:
group "frontends" => "frontend[01..04]";
Using server.ini
The same group definition can be stored in a server.ini file:
[frontends]
frontend[01..04]
Your tasks
Create a task description
desc "This is a long description of a task";
Create the task
task "shortname", group => "frontends", sub {
run "uptime";
};
or, if you don't have groups
task "shortname", "frontend01", "frontend02", "frontend03", "frontend04", sub {
run "uptime";
};
and with serverranges
task "shortname", "frontend[01..04]", sub {
run "uptime";
};
perl v5.20.2 2015-09-04 REX(1)
