MySQL启动错误--为IPv4‘127.0.0.1’创建套接字失败: errno: 13

Question

我要为这件事把头发拔出来。令人意外的是(看起来，我已经几个星期没有登录到服务器了) mysql死了，我无法重新启动它。我在Ubuntu 14.04。尝试重新启动时，日志中会显示以下内容：

170502 18:00:57 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306
170502 18:00:57 [Note]   - '127.0.0.1' resolves to '127.0.0.1';
170502 18:00:57 [ERROR] Failed to create a socket for IPv4 '127.0.0.1': errno: 13.
170502 18:00:57 [ERROR] Can't create IP socket: Permission denied
170502 18:00:57 [ERROR] Aborting

你说是许可？

root@mleserver:~# ls -ld /var/run/mysqld/
drwxr-xr-x 2 mysql mysql 40 May  2 16:46 /var/run/mysqld/

啊，不对。

root@mleserver:~# ls -la /var/lib/mysql
total 2521564
drwx------ 10 mysql mysql       4096 May  2 18:00 .
drwxr-xr-x 55 root  root        4096 May  2 16:51 ..
-rw-r--r--  1 mysql mysql          0 Oct  9  2013 debian-5.1.flag
-rw-r--r--  1 mysql mysql          0 May  2 17:50 debian-5.5.flag
-rw-rw----  1 mysql mysql 2569011200 May  2 18:00 ibdata1
-rw-rw----  1 mysql mysql    5242880 May  2 18:00 ib_logfile0
-rw-rw----  1 mysql mysql    5242880 May  2 18:00 ib_logfile1
drwx------  2 mysql mysql       4096 Aug 15  2016 mleserver_production
drwx------  2 mysql mysql       4096 May  2 17:50 mysql
-rw-rw----  1 mysql mysql          6 Jan 20 06:47 mysql_upgrade_info
drwx------  2 mysql mysql       4096 May  2 17:50 performance_schema

看起来也不坏。

root@mleserver:/tmp# cat /etc/passwd
...
mysql:x:104:111:MySQL Server,,,:/nonexistent:/bin/false

我决定从轨道上核爆它：

sudo apt-get remove --purge mysql*
sudo apt-get autoremove
sudo apt-get autoclean
sudo apt-get install mysql-server mysql-client

但错误仍然存在。有人有什么想法吗？在这一点上，我不介意从头开始重建服务器，但我希望能够从数据库中获取数据.虽然我需要能先连接到它。这是我的my.cnf文件：

[client]
port            = 3306
socket          = /var/run/mysqld/mysqld.sock

[mysqld_safe]
socket          = /var/run/mysqld/mysqld.sock
nice            = 0

[mysqld]
user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking

bind-address            = 127.0.0.1
key_buffer              = 16M
max_allowed_packet      = 16M
thread_stack            = 192K
thread_cache_size       = 8

myisam-recover         = BACKUP

query_cache_limit       = 1M
query_cache_size        = 16M

log_error = /var/log/mysql/error.log

expire_logs_days        = 10
max_binlog_size         = 100M

[mysqldump]
quick
quote-names
max_allowed_packet      = 16M

[mysql]

[isamchk]
key_buffer              = 16M

!includedir /etc/mysql/conf.d/

Answer 1

如果这对其他人有帮助的话，结果是AppArmor拒绝执行。来自syslog

May  2 23:35:51 devanalyzer kernel: [24540.913056] type=1400 audit(1493782551.291:50): apparmor="DENIED" operation="create" parent=1 profile="/usr/sbin/mysqld" pid=25601 comm="mysqld" family="inet" sock_type="stream" protocol=6

我不太关心诊断它，因为我要拆除这台服务器，但我能够绕过它，将所有配置文件设置为抱怨模式，而不是强制模式：

sudo aa-complain /etc/apparmor.d/*

在此之后，sudo service mysql start按预期工作。