Laravel Meetup Groningen 27 november 2018

1. Multi-tenant Laravel
How to build a SaaS application with separated databases

2. Intro
Peter Mein
Lead Developer at Rapide Internet
Laravel
API’s
DevOps
K8’s
At the controls:
Lucas van der Have
Senior Developer bij DossierData

3. Saas? Tenants?
What is SaaS?
What is a tenant?

4. Saas? Tenants?
What is SaaS?
What is a tenant?

5. Saas? Tenants?
What is SaaS?
What is a tenant?
The principle of multi-tenancy is about a single piece of software
serving multiple tenants.

6. Why?
To maintain and service individual customer better
Examples
● CTIP 120+ tables, 50+ tenants, 20m+ geoobjects, total 50gb, single database
● DossierData, 150+ tables, 200+ tenants averaging 1Gb - 5Gb per db
● MKA, 100+ tables, 200+ tenants, 2m+ chatberichten

7. Multi-tenant !== Multi-website
Multi-tenant
1 application codebase serving multiple customers with a distinct dataset
i.e. GMail, Facebook or LinkedIn
Multi-website
1 application codebase serving multiple websites/fronts
i.e. Magento

8. Single database

9. Multi-tenant

10. Database Layout
Example of table structure
Master database RO
Shared database RW
Tenant database RW / RO

11. Separated database

12. #deepdive

13. Request lifecycle
- Request
- Middleware
- Setup tenant connection
- Controller
- Call models from the tenant db
- Call models from a shared or master database
- Inter database relations
- Fire a tenant event
- Return response

14. Setup tenant connection
Determine tenant
Encryption
Changing configs on the fly

15. Setup tenant connection
Determine tenant
Encryption
Changing configs on the fly

16. Setup tenant connection
public function getTenant()
{
$subdomain = $this->getSubdomain();
if ($this->tenant !== null) {
return $this->tenant;
}
return $this->tenant = $this->tenantRepository->findBySubdomain($subdomain);
}
Services/TenantService.php

17. Setup tenant connection
Determine tenant
Encryption
Changing configs on the fly

18. Setup tenant connection
private function getDatabaseCredentialsByTenant(Tenant $tenant): array
{
return [
'hostname' => $tenant->db_host,
'database' => $this->encrypter->decrypt($tenant->db_name),
'username' => $this->encrypter->decrypt($tenant->db_user),
'password' => $this->encrypter->decrypt($tenant->db_pass),
];
}
Services/TenantService.php

19. Setup tenant connection
Determine tenant
Encryption
Changing configs on the fly

20. Setup tenant connection
public function connect(Tenant $tenant = null): bool
{
if ($tenant === null) {
return false;
}
list($hostname, $database, $username, $password) = $this->getDatabaseCredentialsByTenant($tenant);
// Update tenant connection configs
$this->updateConnectionDetails('tenant_database', $hostname, $database, $username, $password);
// Set to shared hostname to same as tenant database, necessary for migration to Galera
$this->updateConnectionDetails('shared_database', $hostname);
$this->reconnectConnection('shared_database');
$this->connection = $this->reconnectConnection('mysql');
return true;
}
Services/ConnectionService.php

21. Setup tenant connection
protected function updateConnectionDetails($connection, $hostname, $database = null, $username = null, $password = null)
{
$settingKey = sprintf('database.connections.%s', $connection);
config(sprintf('%s.host', $settingKey), $hostname);
if ($database !== null) {
config(sprintf('%s.database', $settingKey), $database);
}
if ($username !== null) {
config(sprintf('%s.username', $settingKey), $username);
}
if ($password !== null) {
config(sprintf('%s.password', $settingKey), $password);
}
}
Services/ConnectionService.php

22. Call model from the tenant db
- Primary connection
- Call model as normally
i.e.
- Model::find(1);

23. Call model from shared or master db
- Switch connection of a model or set the default connection on the model
- Retrieve the model using eloquent

24. Call model from shared or master db
class Permission extends Model
{
public function getConnectionName()
{
return 'shared_database';
}
protected $fillable = [
'name',
'description',
'policy'
];
}
Models/Permission.php

25. Inter database relations
- A Role has many Permissions
- Permissions are stored in shared db
- Laravel limitations and how to fix them
- Direction of relations
SELECT * FROM tenant_database.users AS u
JOIN tenant_database.users_roles AS ur ON u.id = ur.user_id
JOIN shared_database.roles AS r ON ur.role_id = r.id
WHERE u.id = 1;

26. Call model from shared or master db
class Permission extends Model
{
...
private function getTableNameForConnection($table, $connection = null)
{
return vsprintf('%s.%s', [$this->getDatabaseNameForConnection($connection), $table]);
}
public function roles()
{
return $this->belongsToMany(
AppModelsRole::class,
$this->getTableNameForConnection('role_permissions', 'tenant_database'),
'permission_id',
'role_id'
);
}
...
}
Models/Permission.php

27. Fire an event
- Only a problem on Async listeners
- Needs a tenant to run

28. Fire an event
abstract class TenantEvent extends Event
{
public function __construct()
{
if (($tenant = $this->getTenantService()->getTenant()) instanceof Tenant) {
$this->setTenant($tenant);
} else {
throw new MissingTenantException();
}
}
public function __sleep()
{
// Unset tenant model for serialization
$this->tenant = null;
// Continue with sleep
return parent::__sleep();
}
public function __wakeup()
{
// Fetch the tenant by id
$this->tenant = $this->getTenantService()->find($this->tenantId);
$this->tenantId = $this->tenant->id;
// Initialize tenant database connection
$this->getTenantManager()->connect($this->tenant);
// Continue with wake up
parent::__wakeup();
}
}
Abstracts/TenantEvent.php

29. Warnings
Everything outside the request lifecycle requires manual tenant switching
Cache
Broadcast
Storage
Queues
Inter database relations and connections to be used
Cross connection transactions

30. Pro’s & Con’s
Backups per tenant
Easy recovery
GDPR
Scalability
Manageability (migrating to new db environment)
Overhead
Complexer logic for built in laravel functions:
- Commands
- Events
- Queues
- Broadcasting
Planning ahead

31. Server layout
Layer 4 load balancing

32. Packages
I don’t want to do this all by myself:
https://github.com/hyn/multi-tenant ★1143
https://github.com/orchestral/tenanti ★406
https://github.com/HipsterJazzbo/Landlord ★525

33. Andere onderwerpen
● Laravel API's and their limitations
● Strangling Laravel with react
● Deploying Laravel to production (With CI)
● Error handling in Laravel with channels and sentry
● Oauth2 implementation with passport (and what its missing)
● Laravel and Kubernetes
● Local development with Docker
● Broadcasting to the world
● Storage in the cloud, and efficient image retrieval (Thumbor and S3)
● Unit testing, Integration testing, Browser testing
● Package development and contributing to open source
● Modular laravel; simulate microservices
https://sli.do #F294

34. Questions?

35. Thank you