mysqld: File './binlog.index' not found (OS errno 13 - Permission denied)

mysqld: File './binlog.index' not found (OS errno 13 - Permission denied)

env：

NAME="CentOS Linux"
VERSION="7 (Core)"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="7"
PRETTY_NAME="CentOS Linux 7 (Core)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:7"
HOME_URL="https://www.centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7"
CENTOS_MANTISBT_PROJECT_VERSION="7"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="7"

/usr/sbin/mysqld  Ver 8.0.19 for Linux on x86_64 (MySQL Community Server - GPL)

concluson for those impatient

1. see your mysql config file
2. make sure all the configurations in your config file is owned by user mysql && group mysql
3. if not, just change their ownship and owner group to mysql

progress

1. view log
   get useful log in file /var/log/mysqld.log like below

   mysqld: File './binlog.index' not found (OS errno 13 - Permission denied)
   2020-03-06T08:04:17.833206Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.19) starting as process 16352
   2020-03-06T08:04:17.835908Z 0 [ERROR] [MY-010119] [Server] Aborting
   

2. check my config file
   my config looks like below:

   # For advice on how to change settings please see
   # http://dev.mysql.com/doc/refman/8.0/en/server-configuration-defaults.html
   
   [mysqld]
   #
   # Remove leading # and set to the amount of RAM for the most important data
   # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
   # innodb_buffer_pool_size = 128M
   #
   # Remove the leading "# " to disable binary logging
   # Binary logging captures changes between backups and is enabled by
   # default. It's default setting is log_bin=binlog
   # disable_log_bin
   #
   # Remove leading # to set options mainly useful for reporting servers.
   # The server defaults are faster for transactions and fast SELECTs.
   # Adjust sizes as needed, experiment to find the optimal values.
   # join_buffer_size = 128M
   # sort_buffer_size = 2M
   # read_rnd_buffer_size = 2M
   #
   # Remove leading # to revert to previous value for default_authentication_plugin,
   # this will increase compatibility with older clients. For background, see:
   # https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_default_authentication_plugin
   default-authentication-plugin=mysql_native_password
   
   datadir=/var/lib/mysql
   socket=/var/lib/mysql/mysql.sock
   
   log-error=/var/log/mysqld.log
   pid-file=/var/run/mysqld/mysqld.pid
   

   throught checking i found:

   ls -al /var/lib/mysql
   total 168068
   drwxr-x---   2 mysql mysql     4096 Mar  6 15:59 #innodb_temp
   drwxr-x--x   6 mysql mysql     4096 Mar  6 16:04 .
   drwxr-xr-x. 30 root  root      4096 Mar  6 13:14 ..
   -rw-r-----   1 mysql mysql       56 Mar  6 13:33 auto.cnf
   -rw-r-----   1 mysql mysql     1167 Mar  6 14:33 binlog.000001
   -rw-r-----   1 mysql mysql      971 Mar  6 14:40 binlog.000002
   -rw-r-----   1 mysql mysql      178 Mar  6 15:27 binlog.000003
   -rw-r-----   1 mysql mysql      199 Mar  6 15:43 binlog.000004
   -rw-r-----   1 mysql mysql      178 Mar  6 15:44 binlog.000005
   -rw-r-----   1 root  root       178 Mar  6 15:45 binlog.000006
   -rw-r-----   1 root  root       178 Mar  6 15:46 binlog.000007
   -rw-r-----   1 root  root       178 Mar  6 15:46 binlog.000008
   -rw-r-----   1 root  root       178 Mar  6 15:47 binlog.000009
   -rw-r-----   1 root  root       178 Mar  6 15:49 binlog.000010
   -rw-r-----   1 root  root       178 Mar  6 15:49 binlog.000011
   -rw-r-----   1 root  root       178 Mar  6 15:49 binlog.000012
   -rw-r-----   1 root  root       178 Mar  6 15:58 binlog.000013
   -rw-r-----   1 root  root       155 Mar  6 15:59 binlog.000014
   -rw-r-----   1 root  root       224 Mar  6 15:59 binlog.index
   -rw-------   1 mysql mysql     1680 Mar  6 13:33 ca-key.pem
   -rw-r--r--   1 mysql mysql     1112 Mar  6 13:33 ca.pem
   -rw-r--r--   1 mysql mysql     1112 Mar  6 13:33 client-cert.pem
   -rw-------   1 mysql mysql     1680 Mar  6 13:33 client-key.pem
   -rw-r-----   1 root  root      3329 Mar  6 15:58 ib_buffer_pool
   -rw-r-----   1 mysql mysql 50331648 Mar  6 15:59 ib_logfile0
   -rw-r-----   1 mysql mysql 50331648 Mar  6 13:33 ib_logfile1
   -rw-r-----   1 mysql mysql 12582912 Mar  6 15:59 ibdata1
   -rw-r-----   1 root  root  12582912 Mar  6 15:59 ibtmp1
   drwxr-x---   2 mysql mysql     4096 Mar  6 13:33 mysql
   -rw-r-----   1 mysql mysql 25165824 Mar  6 15:59 mysql.ibd
   srwxrwxrwx   1 root  root         0 Mar  6 15:59 mysql.sock
   -rw-------   1 root  root         6 Mar  6 15:59 mysql.sock.lock
   drwxr-x---   2 mysql mysql     4096 Mar  6 13:33 performance_schema
   -rw-------   1 mysql mysql     1680 Mar  6 13:33 private_key.pem
   -rw-r--r--   1 mysql mysql      452 Mar  6 13:33 public_key.pem
   -rw-r--r--   1 mysql mysql     1112 Mar  6 13:33 server-cert.pem
   -rw-------   1 mysql mysql     1676 Mar  6 13:33 server-key.pem
   drwxr-x---   2 mysql mysql     4096 Mar  6 13:33 sys
   -rw-r-----   1 mysql mysql 10485760 Mar  6 15:59 undo_001
   -rw-r-----   1 mysql mysql 10485760 Mar  6 15:59 undo_002
   
   
   ls -al /var/run/mysqld/mysqld.pid
   -rw-r----- 1 root root 6 Mar  6 15:59 /var/run/mysqld/mysqld.pid
   

   3. change owner ship and owner group

   chgrp mysql -R /var/lib/mysql
   chown mysql -R /var/run/mysqld
   
   chgrp mysql -R /var/run/mysqld
   chown mysql -R /var/run/mysqld
   

   4. restart mysqld service, and your problem fixed