Craft 3 DDEV Migration: "No database has been selected yet"

Question

I've hit a snag while trying to move my Craft 3 project from MAMP to DDEV. First I installed a new DDEV project using the php project type and MySQL 8.0 for the database. Then I imported the database to DDEV. Then I updated my .env variables with the following values:

DB_DRIVER="mysql"
DB_SERVER="db"
DB_PORT="3306"
DB_DATABASE="db"
DB_USER="db"
DB_PASSWORD="db"
DB_SCHEMA=public
DB_TABLE_PREFIX=

After that I launched the project in the browser, navigated to the control panel, and got hit with this error:

No database has been selected yet.

I was able to successfully connect to the database using a plain PHP test script, but Craft can't for some reason.

Aside from checking and re-checking the .env settings I'm not exactly sure how else to troubleshoot this. The fact that Craft seems to think this is an installation issue is probably a clue, though I'm not really sure how.

I ran php craft setup/db-creds and here's what I got back:

Which database driver are you using? (mysql or pgsql) [mysql] 
Database server name or IP address: [db] 
Database port: [3306] 
Database username: [db] 
Use the password provided by $DB_PASSWORD? (yes|no) [yes]:no
Database password: 
Database name: [db] 
Database table prefix: 
Testing database credentials ... failed: SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: nodename nor servname provided, or not known

Here's what my config/db.php file looks like:

return [
    'dsn' => getenv('DB_DSN'),
    'user' => getenv('DB_USER'),
    'password' => getenv('DB_PASSWORD'),
    'schema' => getenv('DB_SCHEMA'),
    'tablePrefix' => getenv('DB_TABLE_PREFIX'),
];

Here's my ddev describe output:

┌───────────────────────────────────────────────────────────────────────────────────────────────────┐
│ Project: my-project ~/My/Project/Location/my-project https://my-project.ddev.site  │
│ Docker platform: docker-desktop                                                                   │
│ Router: traefik                                                                                   │
├──────────┬──────┬──────────────────────────────────────────────────────────┬──────────────────────┤
│ SERVICE  │ STAT │ URL/PORT                                                 │ INFO                 │
├──────────┼──────┼──────────────────────────────────────────────────────────┼──────────────────────┤
│ web      │ OK   │ https://my-project.ddev.site                        │ php PHP8.1           │
│          │      │ InDocker: web:443,80,8025                                │ nginx-fpm            │
│          │      │ Host: 127.0.0.1:55134,55133                              │ docroot:'dist'       │
│          │      │                                                          │ Mutagen enabled (ok) │
│          │      │                                                          │ NodeJS:18            │
├──────────┼──────┼──────────────────────────────────────────────────────────┼──────────────────────┤
│ db       │ OK   │ InDocker: db:3306                                        │ mysql:8.0            │
│          │      │ Host: 127.0.0.1:55132                                    │ User/Pass: 'db/db'   │
│          │      │                                                          │ or 'root/root'       │
├──────────┼──────┼──────────────────────────────────────────────────────────┼──────────────────────┤
│ Mailpit  │      │ Mailpit: https://my-project.ddev.site:8026          │                      │
│          │      │ `ddev launch -m`                                         │                      │
├──────────┼──────┼──────────────────────────────────────────────────────────┼──────────────────────┤
│ All URLs │      │ https://my-project.ddev.site,                       │                      │
│          │      │ https://127.0.0.1:55134,                                 │                      │
│          │      │ http://my-project.ddev.site, http://127.0.0.1:55133 │                      │
└──────────┴──────┴──────────────────────────────────────────────────────────┴──────────────────────┘

Here's the full Craft error log:

yii\base\InvalidConfigException: No database has been selected yet. in /var/www/html/craft/vendor/craftcms/cms/src/controllers/InstallController.php:320
Stack trace:
#0 /var/www/html/craft/vendor/craftcms/cms/src/controllers/InstallController.php(73): craft\controllers\InstallController->_checkDbConfig()
#1 [internal function]: craft\controllers\InstallController->actionIndex()
#2 /var/www/html/craft/vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array(Array, Array)
#3 /var/www/html/craft/vendor/yiisoft/yii2/base/Controller.php(178): yii\base\InlineAction->runWithParams(Array)
#4 /var/www/html/craft/vendor/yiisoft/yii2/base/Module.php(552): yii\base\Controller->runAction('index', Array)
#5 /var/www/html/craft/vendor/craftcms/cms/src/web/Application.php(295): yii\base\Module->runAction('install/index', Array)
#6 /var/www/html/craft/vendor/craftcms/cms/src/web/Application.php(562): craft\web\Application->runAction('install/index')
#7 /var/www/html/craft/vendor/craftcms/cms/src/web/Application.php(203): craft\web\Application->_processInstallRequest(Object(craft\web\Request))
#8 /var/www/html/craft/vendor/yiisoft/yii2/base/Application.php(384): craft\web\Application->handleRequest(Object(craft\web\Request))
#9 /var/www/html/dist/index.php(21): yii\base\Application->run()
#10 {main}

Answer 1

It looks like you’re specifying a DB_DSN in your config/db.php file, but your .env file isn’t defining that variable.

You either need to specify the full DB_DSN string in your .env file or update your config/db.php file to pull in the individual database connection settings from your .env file.