Skip to main content

​
Overview

DatabaseMigrationTools is a .NET Framework 4.7.2 console application (NuGet job) that runs Entity Framework Code First database migrations against the four core SQL Server databases used by NuGet.org:
  • GalleryDatabase — the primary NuGet package index store
  • SupportRequestDatabase — admin support ticket data
  • ValidationDatabase — package signing / validation pipeline state
  • CatalogValidationDatabase — catalog consistency validation state
The tool is invoked as part of the deployment pipeline. It accepts a single MigrationTargetDatabase argument that selects which database to migrate. A separate NuGet package is published for each target (four .nuspec files), allowing deployment pipelines to trigger migrations independently per database.
The tool adds a hard 30-second Thread.Sleep after the job completes. This is a documented workaround for an Application Insights SDK bug where TelemetryChannel.Flush() is unreliable.

​
Role in System

Deployment Gate

Runs as a post-deploy step (via Scripts/PostDeploy.ps1 → RunJob.cmd) before traffic is shifted to a new deployment slot, ensuring the schema is always ahead of the application code.

Multi-Database Fan-Out

A single compiled binary covers all four databases. The MigrationTargetDatabase argument selects the context at runtime, so four separate NuGet packages can be published from one build artifact.

Entra ID–Aware

All *DbMigrationContext classes capture the SQL connection’s AccessToken at construction time and restore it before every EF context creation via SetSqlConnectionAccessToken(), supporting MSI / service principal authentication.

Migration Safety Check

Before applying any pending migration, Job.CheckIsValidMigration() compares the ordered list of applied database migrations against the local code migrations to detect history divergence.

​
Key Files and Classes

Classes in the companion library NuGet.Services.DatabaseMigration:

​
Dependencies

​
NuGet Packages

​
Internal Project References

​
Deployment Flow

​
Notable Patterns and Quirks

Static context factory pattern. Each *DbMigrationContext constructor assigns a lambda to a static *ContextFactory property. This side-effectful static mutation works for a single-run console job but would break under concurrent or parallel migration runs in the same process.
Access token renewal gap. SetSqlConnectionAccessToken() only resets the token when SqlConnection.State == ConnectionState.Closed. If a token expires mid-migration while the connection is open, the migration will fail. Long-running schema changes on databases with short token lifetimes are a risk.
Skipped Gallery migration. Job.cs hard-codes SkipGalleryDatabaseMigrationFile = "201304262245205_CuratedPackagesUniqueIndex". This migration exists in the database history but has no corresponding local file; the validation loop skips it to avoid a spurious divergence error.
Migration script logging. Before calling migrator.Update(), the job uses MigratorScriptingDecorator to generate and log the full SQL for all pending migrations — making the deployment log an audit trail of every DDL statement applied.
Validation check is partially disabled. CheckIsValidMigration contains commented-out guards that would throw when either the database or local migration list is empty. Empty-list scenarios are currently silently allowed.