Hey there! Let's walk through these common Docker/MySQL hiccups one by one—they're totally normal when you're just getting started, so let's get you sorted.

1. Fixing Adminer's SQLSTATE[HY000] [2002] No such file or directory Error #

This error pops up because Adminer defaults to using a local Unix socket for connections, but in Docker, your MySQL container runs as a separate service accessible only via TCP. Here's how to fix it:

• When logging into Adminer: Instead of leaving the "Server" field blank or using localhost, enter the exact name of your MySQL service from your docker-compose.yml (e.g., if your service is named db, type db here).
• Verify your Docker Compose config: Docker Compose automatically creates a shared network for all services in the file, so as long as you didn't override network settings, Adminer and MySQL should be able to communicate.

Here's a minimal working docker-compose.yml for Adminer + MySQL:

version: '3.8'
services:
  db:
    image: mysql:8.0
    environment:
      MYSQL_ROOT_PASSWORD: your_secure_password
      MYSQL_DATABASE: your_default_db
    volumes:
      - mysql_data:/var/lib/mysql # Persist data between container restarts
  adminer:
    image: adminer
    ports:
      - "8080:8080"
    depends_on:
      - db
volumes:
  mysql_data:

2. Resolving phpMyAdmin's "Unknown Authentication Method" Error #

This is a classic conflict between MySQL 8.0's default caching_sha2_password authentication plugin and older versions of phpMyAdmin (or underlying PHP) that don't support it. You have two straightforward fixes:

Option 1: Force MySQL to use the legacy authentication plugin #

Add a command to your MySQL service in docker-compose.yml to switch to mysql_native_password:

services:
  db:
    image: mysql:8.0
    environment:
      MYSQL_ROOT_PASSWORD: your_secure_password
    command: --default-authentication-plugin=mysql_native_password # Add this line

Option 2: Use the latest phpMyAdmin image #

The newest phpmyadmin/phpmyadmin images support caching_sha2_password out of the box. Update your phpMyAdmin service config like this:

phpmyadmin:
    image: phpmyadmin/phpmyadmin:latest
    ports:
      - "8081:80"
    environment:
      PMA_HOST: db # Match your MySQL service name
    depends_on:
      - db

3. Fixing phpMyAdmin's "Address Resolution Failed" with MySQL 5.7 #

This almost always comes down to incorrect service naming or timing issues (phpMyAdmin tries to connect before MySQL is fully ready). Here's how to fix it:

• Explicitly set the PMA_HOST variable: Make sure your phpMyAdmin service points directly to your MySQL service name. For example:

  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    ports:
      - "8081:80"
    environment:
      PMA_HOST: db # Must match your MySQL service name in docker-compose.yml
      PMA_PORT: 3306
    depends_on:
      - db
  

• Add health checks to wait for MySQL: The depends_on directive only ensures MySQL starts first, not that it's ready to accept connections. Add a health check to your MySQL service to let phpMyAdmin wait until it's fully initialized:

  db:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: your_secure_password
    volumes:
      - mysql_data:/var/lib/mysql
    healthcheck:
      test: ["CMD", "mysqladmin", "ping", "-h", "localhost", "-u", "root", "-p${MYSQL_ROOT_PASSWORD}"]
      interval: 10s
      timeout: 5s
      retries: 5
  

  Then update phpMyAdmin's depends_on to respect the health check:

  phpmyadmin:
    # ... other config ...
    depends_on:
      db:
        condition: service_healthy
  

Quick Final Checks #

• Double-check that all service names in docker-compose.yml match what you're entering in Adminer/phpMyAdmin's server field.
• Confirm you're using the exact root password set in MYSQL_ROOT_PASSWORD.
• If you made changes to your config, run docker-compose down -v (to clear old volumes) then docker-compose up -d to start fresh.

内容的提问来源于stack exchange，提问作者user2243747