Ubuntu22.04下PHPMyAdmin连外部服务器报ERR_CONNECTION_REFUSED求助

在Ubuntu 22.04环境中，尝试访问http://192.168.10.165/phpmyadmin，让PHPMyAdmin连接外部服务器上的MariaDB时，出现ERR_CONNECTION_REFUSED错误。

涉及服务器列表 #

• masterDB（192.168.10.165）
• maxscale（192.168.10.175）
• phpmyadmin（192.168.10.185）

相关配置信息 #

1. /etc/phpmyadmin/config.inc.php配置：

$i++;
$cfg['Servers'][$i]['host'] = '192.168.10.165';
$cfg['Servers'][$i]['user'] = 'phpmyadmin';
$cfg['Servers'][$i]['password'] = 'test123';
$cfg['Servers'][$i]['auth_type'] = 'config';
$cfg['Servers'][$i]['connect_type'] = 'socket';
$cfg['Servers'][$i]['socket'] = '/var/run/mysqld/mysqld.sock';

2. MariaDB部分配置：

[mysqld]

pid-file                = /run/mysqld/mysqld.pid
basedir                 = /usr
socket=/run/mysqld/mysqld.sock

bind-address            = 0.0.0.0
proxy_protocol_networks = 192.168.10.175/24, localhost
server-id  =  1
max_connections        = 5000
log_error = /var/log/mysql/error.log
log_bin                = /var/log/mysql/mysql-bin.log
expire_logs_days        = 10
character-set-server  = utf8mb4
collation-server      = utf8mb4_general_ci

3. PHPMyAdmin账号权限：

+---------------------------------------------------------------------------------------------------------------------------------+
| Grants for phpmyadmin@192.168.10.185                                                                                           |
+---------------------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO `phpmyadmin`@`192.168.10.185` IDENTIFIED BY PASSWORD '*9678F24DBDAFA9F106368B335C371B581501E926' |
+---------------------------------------------------------------------------------------------------------------------------------+

4. MaxScale配置：

[maxscale]
threads=auto
log_info=true
log_warn_super_user=true
syslog=true
maxlog=true

[MariaDB-Monitor]
type=monitor
module=mariadbmon
servers=masterDB, replicaDB1, replicaDB2
user=monitor
password=test123
monitor_interval=2s

[masterDB]
type=server
address=192.168.10.165
port=3306
protocol=MariaDBBackend
proxy_protocol=true
monitoruser=monitor
monitorpw=test123
persistpoolmax=5000
max_routing_connections=3000
persistmaxtime=3600s

[Write-Service]
type=service
router=readconnroute
router_options=master, slave
servers=masterDB
user=maxscale
password=test123
idle_session_pool_time=15s
multiplex_timeout=40s
max_connections=2000

[Write-Listener]
type=listener
service=Write-Service
protocol=MariaDBClient
port=3309
address=0.0.0.0

尝试操作与疑问 #

曾推测proxy_protocol_networks参数导致问题，将$cfg['Servers'][$i]['host']从192.168.10.165改为192.168.10.175:3309，但错误依旧；访问http://192.168.10.185/phpmyadmin时还出现NOT FOUND错误。

希望了解：

• 如何解决ERR_CONNECTION_REFUSED错误
• proxy_protocol_networks参数是否可能引发该错误

后续排查结果 #

经确认，错误由两个原因导致：

• URL错误（正确URL应为http://192.168.10.185/phpmyadmin）
• /etc/phpmyadmin/config.inc.php配置错误（已修正相关参数）

内容的提问来源于stack exchange，提问作者hekke