Multi-tenant ASP.NET Core

This is demo project for my Multi-tenant ASP.NET Core presentation. It demonstrates multi-tenant solutions I have worked out for ASP.NET Core. I'm using the same demo also for presentations. Solutions provided here are not absolute truth. There are cases when something different is needed and then the code here serves as a good starting point.

Features

There are multiple features and solutions demonstrated in demo application:

• Using database per tenant strategy
• Using shared database for tenants
• Multi-tenant EF Core database context with security net
• Loading tenants configuration
• Missing tenant middleware
• Tenants provider to get current tenant
• Tenant-based dependency injection
• Unit-testing multi-tenant database context (coming soon)
• Multi-tenant configurable composite commands

Setting every thing up

To demonstrate multi-tenant features I have built I'm using SQL Server LocalDB and MySQL databases. SQL Server LocalDB uses integrated security. For MySQL some user account is needed to access database. Those who plan to run this example on Linux must use some Linux version of SQL Server or SQL Server running on some other machine.

There are two web applications in the solution:

• AspNetCoreMultitenant.Web - safe multitenant web application to use as an example and starting point
• AspNetCoreMultitenant.WebDangerous - dangerous approach to shared resources (shared database tables)

AspNetCoreMultitenant.Web defines three tenants:

• bigcorp - uses dedicated MySQL database
• sme1 - uses SQL Server database
• sme2 - uses SQL Server database

AspNetCoreMultitenant.WebDangerous defines two tenants:

• sme1 - uses same SQL Server database as sme2
• sme2 - uses same SQL Server database as sme1

There are also some host name mappings needed to run this demo on local machine:

• 127.0.0.1 bigcorp
• 127.0.0.1 sme1
• 127.0.0.1 sme2

Web application uses port 5000 and it must be added to URL of all tenants:

• http://bigcorp:5000
• http://sme1:5000
• http://sme2:5000

Dangerous web application uses port 5001 and it must be added to URL of all tenants:

• http://sme1:5001
• http://sme2:5001

When using public server to host this application make sure you turn on HTTPS in application startup.

Concepts

This solution has some important concepts to know:

• Tenant source - class that knows how to read tenant definitions from tenants store
• Tenant provider - class that knows how to find current tenant
• Dynamic cache key provider - class that provides EF Core with caching keys for DbContext model
• Missing tenant middleware - ASP.NET Core request pipeline middleware that acts when tenant is not found