AppArmor 是一款与SeLinux类似的安全框架/工具，其主要作用是控制应用程序的各种权限，例如对某个目录/文件的读/写，对网络端口的打开/读/写等等。
来之Novell网站的引用：
AppArmor is designed to provide easy-to-use application security for both servers and workstations. Novell AppArmor is an access control system that lets you specify per program which files the program may read, write, and execute. AppArmor secures applications by enforcing good application behavior without relying on attack signatures, so it can prevent attacks even if they are exploiting previously unknown vulnerabilities
AppArmor通过一个配置文件（即profile）来指定一个应用程序的相关权限。在大多数情况下，可以通过限制应用程序的某些不必要的权限来提升系统安全性，本人在 打造私有的DNS 服务 和 apparmor 引起自定义mysql 日志问题 就遇到了安全问题
AppArmor是 Ubuntu 的默认选择，但在默认情况下，系统自带安装的profile配置文件很少，通过命令：sudo apt-get install apparmor-profiles，可以安装额外的AppArmor-profile文件。
在Ubuntu下通过命令sudo apparmor_status可以查看当前AppArmor的状态。
执行sudo apt-get install apparmor-profiles命令之前的自带profile配置：
$ sudo apparmor_status apparmor module is loaded. 6 profiles are loaded. 6 profiles are in enforce mode. /sbin/dhclient /usr/lib/NetworkManager/nm-dhcp-client.action /usr/lib/connman/scripts/dhclient-script /usr/sbin/mysqld /usr/sbin/ntpd /usr/sbin/tcpdump 0 profiles are in complain mode. 4 processes have profiles defined. 4 processes are in enforce mode. /sbin/dhclient (471) /sbin/dhclient (1088) /usr/sbin/mysqld (886) /usr/sbin/ntpd (4131) 0 processes are in complain mode. 0 processes are unconfined but have a profile defined.
执行sudo apt-get install apparmor-profiles命令之后的情况：
$ sudo apparmor_status
apparmor module is loaded.
42 profiles are loaded.
9 profiles are in enforce mode.
/sbin/dhclient
/usr/lib/NetworkManager/nm-dhcp-client.action
/usr/lib/chromium-browser/chromium-browser//browser_java
/usr/lib/chromium-browser/chromium-browser//browser_openjdk
/usr/lib/chromium-browser/chromium-browser//sanitized_helper
/usr/lib/connman/scripts/dhclient-script
/usr/sbin/mysqld
/usr/sbin/ntpd
/usr/sbin/tcpdump
33 profiles are in complain mode.
/sbin/klogd
/sbin/syslog-ng
/sbin/syslogd
/usr/lib/chromium-browser/chromium-browser
/usr/lib/chromium-browser/chromium-browser//chromium_browser_sandbox
/usr/lib/chromium-browser/chromium-browser//lsb_release
/usr/lib/chromium-browser/chromium-browser//xdgsettings
/usr/lib/dovecot/anvil
/usr/lib/dovecot/auth
/usr/lib/dovecot/config
/usr/lib/dovecot/deliver
/usr/lib/dovecot/dict
/usr/lib/dovecot/dovecot-auth
/usr/lib/dovecot/dovecot-lda
/usr/lib/dovecot/imap
/usr/lib/dovecot/imap-login
/usr/lib/dovecot/lmtp
/usr/lib/dovecot/log
/usr/lib/dovecot/managesieve
/usr/lib/dovecot/managesieve-login
/usr/lib/dovecot/pop3
/usr/lib/dovecot/pop3-login
/usr/lib/dovecot/ssl-params
/usr/sbin/avahi-daemon
/usr/sbin/dnsmasq
/usr/sbin/dovecot
/usr/sbin/identd
/usr/sbin/mdnsd
/usr/sbin/nmbd
/usr/sbin/nscd
/usr/sbin/smbd
/usr/{sbin/traceroute,bin/traceroute.db}
/{usr/,}bin/ping
4 processes have profiles defined.
4 processes are in enforce mode.
/sbin/dhclient (581)
/sbin/dhclient (1115)
/usr/sbin/mysqld (924)
/usr/sbin/ntpd (3684)
0 processes are in complain mode.
0 processes are unconfined but have a profile defined.可以看到新安装了一些profile配置文件。Apparmor的profile配置文件均保存在目录/etc/apparmor.d，对应的日志文件记录在/var/log/messages。
Apparmor使用内核标准安全文件系统机制（/sys/kernel/security）来加载和监控profiles文件。而虚拟文件/sys/kernel/security/apparmor/profiles里记录了当前加载的profiles文件。
重启apparmor，Apparmor的启动、停止等操作的相关命令如下：
Start : sudo /etc/init.d/apparmor start
Stop : sudo /etc/init.d/apparmor stop
reload: sudo /etc/init.d/apparmor reload
Show status: sudo /etc/init.d/apparmor status
原文地址：Ubuntu apparmor何方神圣
标签：apparmor ubuntu mysql dns