Rex is a framework that simplifies system administration tasks like user management, package installation, service management, and configuration across multiple servers. It uses a simple domain-specific language in Perl scripts called Rexfiles to define tasks that can be run remotely on groups of servers via SSH. Predefined modules help perform common operations such as deploying code to application servers. Rex aims to provide traceable, testable deployments and make rollbacks easy.

1. (R)?ex - A framework to simplify system administration

2. for s in $(cat $HOME/myserver.lst); do ssh root@$s “useradd -m myuser“ scp files/zabbix_agentd.conf root@$s:/etc/zabbix done

3. Hosted Cloud Services

4. Configuration Management

5. (R)?ex - Remote Execution

6. CentOS, Debian, Fedora, Gentoo, Mageia, OpenSuSE, Ubuntu, ...

7. FreeBSD, NetBSD, OpenBSD

8. Solaris 10/11

9. CPAN

10. Wie funktioniert‘s? Ganz grob, so was ähnliches wie Make

11. Es gibt ein Rexfile

12. Ein normales Perl Script

13. Userverwaltung

14. Paketverwaltung

15. Dienstverwaltung

16. Konfigurationsverwaltung

17. Filterregeln (iptables) Configmanagement

18. Usermanagement task “create_user“, sub { create_user “myuser“ => { groups => [“wheel“, “users“], password => “foobar“, ssh_key => “ssh-rsa AAAAB3NzaC1yc2EAAAADAQ...“, }; }; bash# rex -H “server[1..9]“ create_user

19. Paketverwaltung task “install_packages“, sub { install package => [ “ sudo“, “ apache2“, “ php5“, ... ]; }; bash# rex -H “server[1..9]“ install_packages

20. Dienstverwaltung task “start_services“, sub { service apache2 => “start“; service mysql => “start“; service apache2 => “ensure“, “started“; }; bash# rex -H “server[1..9]“ start_services

21. Konfiguration task “configure_monitoring“, sub { file “/etc/zabbix/zabbix_agentd.conf“, source => “files/etc/zabbix/zabbix_agentd.conf“, owner => “root“,

22. group => “root“,