1REX(1) User Contributed Perl Documentation REX(1)
2
6 (R)?ex - (Remote)? Execution
7
9 Rex is a command line tool which executes commands on remote servers.
10 Define tasks in Perl and execute them on remote servers or groups of
11 servers.
12 Rex can be used to:
14 - Deploy web applications to servers sequentially or in parallel.
16 - Automate common tasks.
17 - Provision servers using Rex's builtin tools.
18
20 bash# rex -h # Show usage
21 bash# rex -T # List tasks
22 bash# rex uname # Run the 'uname' task
23 bash# rex -H server[01..10] uname # Run the 'uname' task on all the specified hosts
24 bash# rex -G production uname # Run 'uname' on hosts on the 'production' hostgroup
25 bash# rex deploy --gracefully # Pass '--gracefully' to the 'deploy' task
26
28 rex [<options>] [-H <host>] [-G <group>] <task> [<task-options>]
29 rex -T[m|y|v] [<string>]
30 -b Run batch
32 -e Run the given code fragment
33 -E Execute a task on the given environment
34 -G|-g Execute a task on the given server groups
35 -H Execute a task on the given hosts (space delimited)
36 -z Execute a task on hosts from this command's output
37 -K Public key file for the ssh connection
39 -P Private key file for the ssh connection
40 -p Password for the ssh connection
41 -u Username for the ssh connection
42 -d Show debug output
44 -ddd Show more debug output (includes profiling output)
45 -m Monochrome output: no colors
46 -o Output format
47 -q Quiet mode: no log output
48 -qw Quiet mode: only output warnings and errors
49 -Q Really quiet: output nothing
50 -T List tasks
52 -Tm List tasks in machine-readable format
53 -Tv List tasks verbosely
54 -Ty List tasks in YAML format
55 -c Turn cache ON
57 -C Turn cache OFF
58 -f Use this file instead of Rexfile
59 -F Force: disregard lock file
60 -h Display this help message
61 -M Load this module instead of Rexfile
62 -O Pass additional options, like CMDB path
63 -s Use sudo for every command
64 -S Password for sudo
65 -t Number of threads to use (aka 'parallelism' param)
66 -v Display (R)?ex version
67
69 When you run "rex" it reads the file "Rexfile" in the current working
70 directory. A Rexfile consists of 2 major parts: Configuration and Task
71 Definitions.
72 Configuration
74 Simple Authentication
75 user "bruce";
77 password "batman";
78 pass_auth;
79 Key Authentication
81 private_key "/path/to/your/private/key.file";
83 public_key "/path/to/your/public/key.file";
84 Define Logging
86 logging to_file => "rex.log";
88 logging to_syslog => "local0";
89 Group your servers
91 Rex gives you the ability to define groups of servers. Groups can be
93 defined the Rexfile:
94 group "frontends" => "frontend01", "frontend02", "frontend03", "frontend04", "frontend[05..09]";
96 Groups can also be defined in a server.ini file:
98 [frontends]
100 frontend[01..04]
101 Other Configuration
103 timeout 10; # ssh timeout
104 parallelism 2; # execute tasks in parallel
105 Defining tasks
107 A basic task looks like this:
108 # task description
110 desc "This task tells you how long since the server was rebooted";
111 # task definition
113 task "shortname", sub {
114 say run "uptime";
115 };
116 You can also set a default server group:
118 desc "This is a long description of a task";
120 task "shortname", group => "frontends", sub {
121 say run "uptime";
122 };
123perl v5.30.0 2019-07-24 REX(1)