NSchema.Aws 2.0.0

NSchema.Aws

AWS provider for NSchema, the declarative database schema migration library for .NET.

This package plugs an S3-backed implementation of NSchema's ISchemaStateStore into your application, enabling offline migration planning without live database access.

Getting started

Install the core package and this provider:

dotnet add package NSchema
dotnet add package NSchema.Aws

Register the S3 state store against an NSchemaApplicationBuilder:

using NSchema;
using NSchema.Aws;

var builder = NSchemaApplication.CreateBuilder(args);

builder
    .AddSchemasFromAssemblyContaining<Program>()
    .UseCurrentSchemaPostgres(connectionString)
    .UseStateStoreS3("my-bucket", "nschema/state.json");

var app = builder.Build();
await app.Apply();

Configuration

UseStateStoreS3 has three overloads:

// 1. Bucket and key directly.
builder.UseStateStoreS3("my-bucket", "nschema/state.json");

// 2. Configure options via a delegate.
builder.UseStateStoreS3(o =>
{
    o.Bucket = configuration["NSchema:Bucket"]!;
    o.Key = configuration["NSchema:Key"]!;
});

// 3. As above, with access to the IServiceProvider.
builder.UseStateStoreS3((o, sp) =>
{
    var config = sp.GetRequiredService<IConfiguration>();
    o.Bucket = config["NSchema:Bucket"]!;
    o.Key = config["NSchema:Key"]!;
});

By default an AmazonS3Client using ambient credentials (ECS task role, Lambda execution role, environment variables, etc.) is registered automatically. To bring your own client:

// Register via AWSSDK.Extensions.NETCore.Setup before calling UseStateStoreS3.
builder.Services.AddAWSService<IAmazonS3>();
builder.UseStateStoreS3("my-bucket", "nschema/state.json");

IAM permissions

Example policy (scoped to the state object):

{
  "Effect": "Allow",
  "Action": ["s3:GetObject", "s3:PutObject"],
  "Resource": "arn:aws:s3:::my-bucket/nschema/state.json"
}

Locking

State writes are last-write-wins. Concurrent applies will silently overwrite each other's state. This is acceptable when deploys are serialised (e.g. a single ECS task per environment).

License

See LICENSE.