ColaFlow/docs/plans/sprint_2_story_2_task_3.md

task_id, story, status, estimated_hours, created_date, completed_date, assignee

task_id	story	status	estimated_hours	created_date	completed_date	assignee
sprint_2_story_2_task_3	sprint_2_story_2	completed	3	2025-11-05	2025-11-05	Backend Team

Task 3: Add Multi-Tenant Isolation

Story: Story 2 - Audit Log Core Features (Phase 2) Estimated: 3 hours

Description

Ensure audit logs are properly isolated by TenantId to prevent cross-tenant data access. Implement global query filters and verify with comprehensive tests.

Acceptance Criteria

• Global query filter applied to AuditLog entity - VERIFIED
• TenantId automatically set on audit log creation - VERIFIED
• Cross-tenant queries blocked - VERIFIED
• Integration tests verify isolation - VERIFIED
• Security audit passed - VERIFIED

Verification Summary (2025-11-05)

Implementation Status: ✅ COMPLETED (Already implemented in Story 1)

Multi-tenant isolation is fully implemented with defense-in-depth:

1. Layer 1 - Automatic TenantId Setting:

   • AuditInterceptor.cs line 55: var tenantId = TenantId.From(_tenantContext.GetCurrentTenantId());
   • AuditLog.Create() called with tenantId (line 165-173)

2. Layer 2 - Global Query Filter:

   • PMDbContext.cs line 52-53:

   modelBuilder.Entity<AuditLog>().HasQueryFilter(a =>
       a.TenantId == GetCurrentTenantId());
   

3. Layer 3 - Repository Filtering:

   • All repository methods use filtered DbSet
   • AsNoTracking() for performance (no change tracking overhead)

4. Layer 4 - Database Indexes:

   • AuditLogConfiguration.cs line 66-67: Composite index on (TenantId, EntityType, EntityId)
   • Ensures efficient queries and prevents N+1 problems

Implementation Details

Already Implemented in Story 1!

The AuditLogInterceptor already sets TenantId:

var auditLog = new AuditLog
{
    TenantId = _tenantContext.TenantId,
    // ...
};

This Task: Add Global Query Filter and Comprehensive Testing

1. Update EF Configuration: colaflow-api/src/ColaFlow.Infrastructure/Data/Configurations/AuditLogConfiguration.cs

public void Configure(EntityTypeBuilder<AuditLog> builder)
{
    // ... existing configuration ...

    // Multi-tenant global query filter
    // This will be dynamically replaced by TenantContext at runtime
    builder.HasQueryFilter(a => a.TenantId == Guid.Empty);
}

2. Apply Global Filter in DbContext: colaflow-api/src/ColaFlow.Infrastructure/Data/ColaFlowDbContext.cs

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);

    // Apply tenant filter to AuditLog
    var tenantId = _tenantContext.TenantId;
    modelBuilder.Entity<AuditLog>().HasQueryFilter(a => a.TenantId == tenantId);
}

3. Verify Repository Filtering: colaflow-api/src/ColaFlow.Infrastructure/Repositories/AuditLogRepository.cs

public async Task<List<AuditLog>> GetByEntityAsync(string entityType, Guid entityId)
{
    var tenantId = _tenantContext.TenantId;

    // Query automatically filtered by global query filter
    // Explicit TenantId check added for defense-in-depth
    return await _context.AuditLogs
        .Where(a => a.TenantId == tenantId && a.EntityType == entityType && a.EntityId == entityId)
        .OrderByDescending(a => a.Timestamp)
        .AsNoTracking()
        .ToListAsync();
}

Defense-in-Depth Strategy:

1. Layer 1: TenantId automatically set by Interceptor
2. Layer 2: Global Query Filter in EF Core
3. Layer 3: Explicit TenantId checks in Repository
4. Layer 4: Integration tests verify isolation

Testing

Integration Tests: colaflow-api/tests/ColaFlow.Application.IntegrationTests/AuditLog/MultiTenantIsolationTests.cs

public class AuditLogMultiTenantIsolationTests : IntegrationTestBase
{
    [Fact]
    public async Task GetByEntityAsync_ShouldOnlyReturnCurrentTenantAuditLogs()
    {
        // Arrange - Create audit logs for two tenants
        var tenant1Id = Guid.NewGuid();
        var tenant2Id = Guid.NewGuid();
        var entityId = Guid.NewGuid();

        // Tenant 1 creates a project
        SetCurrentTenant(tenant1Id);
        var log1 = new AuditLog
        {
            Id = Guid.NewGuid(),
            TenantId = tenant1Id,
            EntityType = "Project",
            EntityId = entityId,
            Action = AuditAction.Create,
            Timestamp = DateTime.UtcNow
        };
        await Context.AuditLogs.AddAsync(log1);
        await Context.SaveChangesAsync();

        // Tenant 2 tries to access (should fail)
        SetCurrentTenant(tenant2Id);

        var repository = new AuditLogRepository(Context, TenantContext);

        // Act
        var result = await repository.GetByEntityAsync("Project", entityId);

        // Assert
        Assert.Empty(result); // Tenant 2 should NOT see Tenant 1's audit logs
    }

    [Fact]
    public async Task CreateProject_ShouldSetTenantIdAutomatically()
    {
        // Arrange
        var tenantId = Guid.NewGuid();
        SetCurrentTenant(tenantId);

        // Act
        var projectId = await Mediator.Send(new CreateProjectCommand
        {
            Name = "Test Project",
            Key = "TEST"
        });

        // Assert
        var auditLogs = await Context.AuditLogs
            .IgnoreQueryFilters() // Bypass filter to check actual data
            .Where(a => a.EntityId == projectId)
            .ToListAsync();

        Assert.All(auditLogs, log => Assert.Equal(tenantId, log.TenantId));
    }

    [Fact]
    public async Task DirectDatabaseQuery_ShouldRespectGlobalQueryFilter()
    {
        // Arrange
        var tenant1Id = Guid.NewGuid();
        var tenant2Id = Guid.NewGuid();

        // Create logs for both tenants (using IgnoreQueryFilters)
        await Context.AuditLogs.AddAsync(new AuditLog { Id = Guid.NewGuid(), TenantId = tenant1Id, /* ... */ });
        await Context.AuditLogs.AddAsync(new AuditLog { Id = Guid.NewGuid(), TenantId = tenant2Id, /* ... */ });
        await Context.SaveChangesAsync();

        // Act - Set current tenant to tenant1
        SetCurrentTenant(tenant1Id);
        var logs = await Context.AuditLogs.ToListAsync();

        // Assert - Should only see tenant1 logs
        Assert.All(logs, log => Assert.Equal(tenant1Id, log.TenantId));
    }

    [Fact]
    public async Task BypassFilter_ShouldWorkWithIgnoreQueryFilters()
    {
        // For admin/system operations that need to see all tenants
        var allLogs = await Context.AuditLogs
            .IgnoreQueryFilters()
            .ToListAsync();

        Assert.True(allLogs.Count > 0);
    }
}

Security Test Cases:

1. Cross-tenant read blocked
2. TenantId automatically set on creation
3. Global query filter applied
4. IgnoreQueryFilters works for admin operations
5. Repository explicit filtering works

Technical Notes

• Use IgnoreQueryFilters() for admin/system operations only
• Always combine global filter with explicit TenantId checks (defense-in-depth)
• Test with real database, not in-memory (to verify SQL generation)
• Run security tests in CI/CD pipeline

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Created: 2025-11-05 by Backend Agent