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Cheat Sheet
Executing a command and parsing its output
run($command, %options)
Run a remote command and returns its output.
Options
- cwd - Work directory for the command.
- only_if - Executes the command only if the condition completes successfully.
- unless - Executes the command only unless the condition completes successfully.
- only_notified - queues the command, to be executed upon notification.
- env - sets environment variables for the command.
- timeout - try to terminate the command after the given amount of seconds.
- auto_die - die if the command returns with a non-zero exit code.
- command - the command that should be executed.
- creates - If the file given with this option already exists, the command won't be executed.
Example to just run a command if a file doesn't exists
run "/tmp/install_service.sh", creates => "/opt/myservice/conf.xml";Example to run a command and get its output
my @output_lines = run "df -h";Installing and configuring a service
The most used functions in configuration management is installing/managing services and managing configuration files. In Rex you can do this with the file, pkg and service functions.
file($remote_file, %options)
Manage files on remote systems.
Options
- ensure - Defines the state of the file. Valid parameters are present, absent, directory.
- source - The local file that should be uploaded to the remote server.
- content - Set the content directly. Can be used together with the template() function.
- owner - The owner of the file.
- group - The group the file should belong to.
- mode - The file system privileges the file should have.
- no_overwrite - If set to TRUE the file won't be overwritten if the file already exists.
on_change - A callback function that gets called when the file state changed. (For example if the file content was modified).
file "/etc/ntpd.conf", ensure => "present", source => "files/ntpd.conf", owner => "root", group => "root", mode => 644, on_change => sub { service ntpd => "restart"; };
pkg($name, %options)
Install a package on the remote system.
Options
- ensure - Defines the state of the package. Valid parameters are latest, present, absent or the version that should be enforced.
on_change - A called function that gets called when the package state changed. (For example when it was updated)
pkg "ntpd", ensure => "latest", on_change => sub { service ntpd => "restart"; };
service
Manage the state of a service.
This function can be called as a resource or as a normal function to directly stop/start/restart/... services.
Options (for calling as a resource)
- ensure - Defines the state of the service. Valid parameters are started, stopped.
- start - Custom command to start the service.
- stop - Custom command to stop the service.
- status - Custom command to get the status of a service.
- restart - Custom command to restart a service.
- reload - Custom command to reload a service.
Example for calling as resource
service "nptd", ensure => "started";Example for calling as function
service ntpd => "restart";Managing Cron
Manage cron jobs.
cron_entry($entry_name, %options)
Options
- ensure - Defines the state of the cron entry. Valid parameters are present, absent.
- command - The command to run.
- minute - The minute when to run the job.
- hour - The hour when to run the job.
- month - The month when to run the job.
- day_of_week
- day_of_month
- user - The user for the cron job.
on_change - A callback function that gets called when the cron entry state changed.
cron_entry "run-rkhunter", command => "rkhunter --cronjob", minute => 5, hour => 1;
Managing users and groups
Manage local user database.
account($user_name, %options)
Manage user accounts.
Options
- ensure - Defines the state of the account. Valid parameters are present, absent.
- uid - The user id.
- groups - The groups the user should be member of. The first group is the primary.
- home - The home directory.
- expire - Date when the account will expire. Format: YYYY-MM-DD
- password - Cleartext password for the user.
- crypt_password - Crypted password for the user. Available on Linux, OpenBSD and NetBSD.
- system - Create a system user.
- create_home - If the home directory should be created. Valid parameters are TRUE, FALSE.
- ssh_key - Add ssh key to authorized_keys.
comment
account "krimdomu", ensure => "present", # default uid => 509, home => '/home/krimdomu', comment => 'User Account', expire => '2011年05月30日', groups => [ 'users', 'wheel' ], password => 'blahblah', create_home => TRUE, ssh_key => "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQChUw...";
group($group_name, %options)
Manage groups.
Options
- ensure - Defines the state of the group. Valid parameters are present, absent.
- gid - The group id.
system - Create a system group.
group "users", ensure => "present";