Resolve the Current Tenant from the Request Host with a Symfony Argument Resolver

<?php

namespace App\Tenant;

use App\Entity\Tenant;

class TenantContext
{
    private ?Tenant $tenant = null;

    public function setTenant(Tenant $tenant): void
    {
        if ($this->tenant !== null) {
            throw new \LogicException('Tenant has already been resolved for this request.');
        }

        $this->tenant = $tenant;
    }

    public function getTenant(): Tenant
    {
        if ($this->tenant === null) {
            throw new \LogicException('No tenant resolved for the current request.');
        }

        return $this->tenant;
    }

    public function hasTenant(): bool
    {
        return $this->tenant !== null;
    }
}

<?php

namespace App\Tenant;

use App\Entity\Tenant;
use App\Repository\TenantRepository;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Controller\ValueResolverInterface;
use Symfony\Component\HttpKernel\ControllerMetadata\ArgumentMetadata;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;

class TenantValueResolver implements ValueResolverInterface
{
    public function __construct(
        private readonly TenantRepository $tenants,
        private readonly TenantContext $tenantContext,
        private readonly string $baseDomain,
    ) {
    }

    public function resolve(Request $request, ArgumentMetadata $argument): iterable
    {
        if ($argument->getType() !== Tenant::class) {
            return [];
        }

        if ($this->tenantContext->hasTenant()) {
            yield $this->tenantContext->getTenant();

            return;
        }

        $host = $request->getHost();
        $suffix = '.' . $this->baseDomain;

        if (!str_ends_with($host, $suffix)) {
            throw new NotFoundHttpException('No tenant for host ' . $host);
        }

        $slug = substr($host, 0, -\strlen($suffix));
        $tenant = $this->tenants->findOneBy(['slug' => $slug, 'active' => true]);

        if ($tenant === null) {
            throw new NotFoundHttpException(sprintf('Unknown tenant "%s".', $slug));
        }

        $this->tenantContext->setTenant($tenant);

        yield $tenant;
    }
}

parameters:
    app.base_domain: '%env(APP_BASE_DOMAIN)%'

services:
    _defaults:
        autowire: true
        autoconfigure: true

    App\Tenant\TenantContext: ~

    App\Tenant\TenantValueResolver:
        arguments:
            $baseDomain: '%app.base_domain%'
        tags:
            - { name: controller.argument_value_resolver, priority: 150 }