已配置AllowNoPassword，为何phpMyAdmin仍拒绝root无密码登录？

问题描述 #

我用以下Dockerfile搭建MySQL和phpMyAdmin环境（非生产环境，希望root无密码登录）：

FROM ubuntu:latest

# Install packages required for MySQL and phpMyAdmin
RUN apt-get update && \
    DEBIAN_FRONTEND=noninteractive apt-get install -y \
        mysql-server \
        phpmyadmin --no-install-recommends \
        apache2 \
        php \
        php-mbstring \
        php-zip \
        php-gd \
        php-json \
        php-curl \
        php-mysql \
        curl

# Disable password prompt for MySQL root user
RUN echo "mysql-server mysql-server/root_password password ''" | debconf-set-selections && \
    echo "mysql-server mysql-server/root_password_again password ''" | debconf-set-selections

# Enable `AllowNoPassword` in phpMyAdmin
RUN mv /usr/share/phpmyadmin/config.sample.inc.php /usr/share/phpmyadmin/config.inc.php && \
    sed -i "/\$cfg\['Servers'\]\[\$i\]\['AllowNoPassword'\] = false;/d" /usr/share/phpmyadmin/config.inc.php && \
    sed -i "/\$i++/i \$cfg['Servers'][$i]['AllowNoPassword'] = true;" /usr/share/phpmyadmin/config.inc.php

# Enable some PHP mods
RUN service apache2 start && \
    phpenmod mbstring && \
    service apache2 stop

# Configure Apache to serve phpMyAdmin
RUN echo "Include /etc/phpmyadmin/apache.conf" >> /etc/apache2/apache2.conf

# Configure MySQL to be accessible from outside the container
RUN sed -i 's/^.*bind-address.*$/bind-address = 0.0.0.0/' /etc/mysql/mysql.conf.d/mysqld.cnf && \
    #If you dont want connections to linger, keep lines below uncommented
    echo "wait_timeout = 10" >> /etc/mysql/mysql.conf.d/mysqld.cnf && \
    echo "interactive_timeout = 10" >> /etc/mysql/mysql.conf.d/mysqld.cnf && \
    service mysql start && \
    # Create a throwaway database
    mysql -u root -e "CREATE DATABASE mydatabase CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci" && \
    # Creating a user with a blank password
    mysql -u root -e "CREATE USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY ''" && \
    mysql -u root -e "GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION" && \
    mysql -u root -e "ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY ''" && \
    mysql -u root -e "GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION" && \
    mysql -u root -e "FLUSH PRIVILEGES" && \
    # Stop the MySQL service
    service mysql stop


# Expose phpMyAdmin and MySQL port
EXPOSE 80 3306

# Start services
CMD service mysql start && \
    service apache2 start && \
    tail -f /var/log/apache2/access.log

运行容器后，MySQL客户端可以正常无密码连接，但访问localhost:80/phpmyadmin输入root且不填密码时，报错：
Login without a password is forbidden by configuration (see AllowNoPassword)

当前生成的config.inc.php内容如下：

<?php
/**
 * phpMyAdmin sample configuration, you can use it as base for
 * manual configuration. For easier setup you can use setup/
 *
 * All directives are explained in documentation in the doc/ folder
 * or at <https://docs.phpmyadmin.net/>.
 */

declare(strict_types=1);

/**
 * This is needed for cookie based authentication to encrypt password in
 * cookie. Needs to be 32 chars long.
 */
$cfg['blowfish_secret'] = ''; /* YOU MUST FILL IN THIS FOR COOKIE AUTH! */

/**
 * Servers configuration
 */
$i = 0;

/**
 * First server
 */
$cfg['Servers'][$i]['AllowNoPassword'] = true;
$i++;
/* Authentication type */
$cfg['Servers'][$i]['auth_type'] = 'cookie';
/* Server parameters */
$cfg['Servers'][$i]['host'] = 'localhost';
$cfg['Servers'][$i]['compress'] = false;

/**
 * phpMyAdmin configuration storage settings.
 */

/* User used to manipulate with storage */
// $cfg['Servers'][$i]['controlhost'] = '';
// $cfg['Servers'][$i]['controlport'] = '';
// $cfg['Servers'][$i]['controluser'] = 'pma';
// $cfg['Servers'][$i]['controlpass'] = 'pmapass';

/* Storage database and tables */
// $cfg['Servers'][$i]['pmadb'] = 'phpmyadmin';
// $cfg['Servers'][$i]['bookmarktable'] = 'pma__bookmark';
// $cfg['Servers'][$i]['relation'] = 'pma__relation';
// $cfg['Servers'][$i]['table_info'] = 'pma__table_info';
// $cfg['Servers'][$i]['table_coords'] = 'pma__table_coords';
// $cfg['Servers'][$i]['pdf_pages'] = 'pma__pdf_pages';
// $cfg['Servers'][$i]['column_info'] = 'pma__column_info';
// $cfg['Servers'][$i]['history'] = 'pma__history';
// $cfg['Servers'][$i]['table_uiprefs'] = 'pma__table_uiprefs';
// $cfg['Servers'][$i]['tracking'] = 'pma__tracking';
// $cfg['Servers'][$i]['userconfig'] = 'pma__userconfig';
// $cfg['Servers'][$i]['recent'] = 'pma__recent';
// $cfg['Servers'][$i]['favorite'] = 'pma__favorite';
// $cfg['Servers'][$i]['users'] = 'pma__users';
// $cfg['Servers'][$i]['usergroups'] = 'pma__usergroups';
// $cfg['Servers'][$i]['navigationhiding'] = 'pma__navigationhiding';
// $cfg['Servers'][$i]['savedsearches'] = 'pma__savedsearches';
// $cfg['Servers'][$i]['central_columns'] = 'pma__central_columns';
// $cfg['Servers'][$i]['designer_settings'] = 'pma__designer_settings';
// $cfg['Servers'][$i]['export_templates'] = 'pma__export_templates';

/**
 * End of servers configuration
 */

/**
 * Directories for saving/loading files from server
 */
$cfg['UploadDir'] = '';
$cfg['SaveDir'] = '';

/**
 * Whether to display icons or text or both icons and text in table row
 * action segment. Value can be either of 'icons', 'text' or 'both'.
 * default = 'both'
 */
//$cfg['RowActionType'] = 'icons';

/**
 * Defines whether a user should be displayed a "show all (records)"
 * button in browse mode or not.
 * default = false
 */
//$cfg['ShowAll'] = true;

/**
 * Number of rows displayed when browsing a result set. If the result
 * set contains more rows, "Previous" and "Next".
 * Possible values: 25, 50, 100, 250, 500
 * default = 25
 */
//$cfg['MaxRows'] = 50;

/**
 * Disallow editing of binary fields
 * valid values are:
 *   false    allow editing
 *   'blob'   allow editing except for BLOB fields
 *   'noblob' disallow editing except for BLOB fields
 *   'all'    disallow editing
 * default = 'blob'
 */
//$cfg['ProtectBinary'] = false;

/**
 * Default language to use, if not browser-defined or user-defined
 * (you find all languages in the locale folder)
 * uncomment the desired line:
 * default = 'en'
 */
//$cfg['DefaultLang'] = 'en';
//$cfg['DefaultLang'] = 'de';

/**
 * How many columns should be used for table display of a database?
 * (a value larger than 1 results in some information being hidden)
 * default = 1
 */
//$cfg['PropertiesNumColumns'] = 2;

/**
 * Set to true if you want DB-based query history.If false, this utilizes
 * JS-routines to display query history (lost by window close)
 *
 * This requires configuration storage enabled, see above.
 * default = false
 */
//$cfg['QueryHistoryDB'] = true;

/**
 * When using DB-based query history, how many entries should be kept?
 * default = 25
 */
//$cfg['QueryHistoryMax'] = 100;

/**
 * Whether or not to query the user before sending the error report to
 * the phpMyAdmin team when a JavaScript error occurs
 *
 * Available options
 * ('ask' | 'always' | 'never')
 * default = 'ask'
 */
//$cfg['SendErrorReports'] = 'always';

/**
 * You can find more configuration options in the documentation
 * in the doc/ folder or at <https://docs.phpmyadmin.net/>.
 */

尝试移动AllowNoPassword配置位置、使用--no-install-recommends安装均无效。

解决方案 #

问题根源 #

你的config.inc.php里犯了一个索引错误：

• 初始$i = 0，你把AllowNoPassword = true赋值给了$cfg['Servers'][0]
• 随后执行$i++，$i变成1，后面的auth_type、host等配置都赋值给了$cfg['Servers'][1]
• phpMyAdmin实际使用的是第1个服务器配置，而这个配置里没有开启AllowNoPassword，所以报错。

修复步骤 #

方法1：修改Dockerfile中的sed命令

把原来修改phpMyAdmin配置的RUN指令替换成：

# Enable `AllowNoPassword` in phpMyAdmin
RUN mv /usr/share/phpmyadmin/config.sample.inc.php /usr/share/phpmyadmin/config.inc.php && \
    sed -i "/\$cfg\['Servers'\]\[\$i\]\['AllowNoPassword'\] = false;/d" /usr/share/phpmyadmin/config.inc.php && \
    sed -i "/\$cfg\['Servers'\]\[\$i\]\['host'\] = 'localhost';/i \$cfg['Servers'][$i]['AllowNoPassword'] = true;" /usr/share/phpmyadmin/config.inc.php

这个修改会把AllowNoPassword = true插入到host配置的前面，此时$i的值还是0，和服务器的其他配置属于同一个索引。

方法2：直接修正config.inc.php

手动调整配置文件的顺序，确保AllowNoPassword和其他服务器配置在同一个$i索引下：

/**
 * Servers configuration
 */
$i = 0;

/**
 * First server
 */
/* Authentication type */
$cfg['Servers'][$i]['auth_type'] = 'cookie';
/* Server parameters */
$cfg['Servers'][$i]['host'] = 'localhost';
$cfg['Servers'][$i]['compress'] = false;
// 添加在同一个服务器配置块内
$cfg['Servers'][$i]['AllowNoPassword'] = true;
$i++;

额外注意点 #

• 确保$cfg['blowfish_secret']设置了32位字符串（虽然无密码登录可能暂时不影响，但cookie认证需要这个配置，避免其他潜在问题），比如：

  $cfg['blowfish_secret'] = 'abcdefghijklmnopqrstuvwxyz123456';
  

内容的提问来源于stack exchange，提问作者WeAreHawk09