tailieunhanh - Automating Linux and Unix System Administration Second Edition phần 6

Mail là tin nhắn qua cơ chế chính tại các trang web dựa trên UNIX. Bạn sử dụng mail để thông báo cho người sử dụng của sản lượng công việc cron, gửi ra qua e-mail, và nhiều nhà phát triển ứng dụng và SA sử dụng e-mail để gửi thông tin trực tiếp từ các ứng dụng và các kịch bản. | 208 CHAPTER 7 AUTOMATING A NEW SYSTEM INFRASTRUCTURE Routing Mail Mail is the primary message-passing mechanism at UNIX-based sites. You use mail to notify users of cron-job output cfexecd sends cfagent output via e-mail and many application developers and SAs utilize e-mail to send information directly from applications and scripts. Mail relays on internal networks route e-mail and queue it up for the rest of the hosts on the network when remote destinations become unreachable. You should centralize disk space and CPU resources needed for mail queuing and processing. In addition it s simpler to configure a centralized set of mail relays to handle special mail-routing tables and aliases than it is to configure all the mail-transfer agents on all machines at a site. We ll use our etchlamp Debian host as our site s mail relay. We ve built this host entirely using automation so it s the sensible place to continue to focus infrastructure services. We add a CNAME for PROD repl root etc bind debian-ext and it ll simply go out to etchlamp on the next cfexecd run relayhost IN CNAME etchlamp Be sure to increment the serial number in the zone file. We run postfix on all our Debian hosts and we ll stick with postfix as our mail-relay Mail Transfer Agent MTA . The default postfix configuration on etchlamp needs some modifications from the original file placed in etc postfix . Modify the file like this smtpd_banner myhostname ESMTP mail_name Debian GNU biff no appending .domain is the MUA s job. append_dot_mydomain no TLS parameters smtpd_tls_cert_file etc ssl certs smtpd_tls_key_file etc ssl private smtpd_use_tls yes smtpd_tls_session_cache_database btree queue_directory smtpd_scache smtp_tls_session_cache_database btree queue_directory smtp_scache myhostname alias_maps hash etc aliases alias_database hash etc aliases mydestination CHAPTER 7 AUTOMATING A NEW SYSTEM .