Lyo.Postgres 2.0.0

Lyo.Postgres

Shared PostgreSQL host bits for Lyo libraries that own an EF Core schema (Audit, Email, ChangeTracker, EntityReference, etc.). When the consumer options opt in, a thin IHostedService calls DbContext.Database.MigrateAsync at host startup. The rest of the package supplies the pieces every Lyo.*.Postgres package used to re-implement: schema-scoped DbContextOptions building, IDbContextFactory<TContext> registration, design-time option construction, and a standard health probe.

Out of scope: entity models and mappings. Each consumer package owns its own DbContext, entities, and migrations; this package only supplies the plumbing around them.

Features

• Hosted migrations. AddPostgresMigrations<TContext, TOptions>() plus PostgresMigrationHostedService<TContext, TOptions>, driven from the IPostgresMigrationConfig options contract.
• PostgresOptionsBase. Base options class that implements IPostgresMigrationConfig with ConnectionString, EnableAutoMigrations, and a Validate() hook. Derived options supply the schema through the abstract SchemaName property, so a package declares its schema once instead of repeating it on every path that builds a connection.
• PostgresSchema. BuildOptions<TContext>(connectionString, schema) and CreateContext<TContext> produce a context whose migrations history lives at "<schema>"."__EFMigrationsHistory". EnsureAsync issues CREATE SCHEMA IF NOT EXISTS with the schema name escaped.
• PostgresDesignTime.CreateOptions<TContext>. Builds DbContextOptions<TContext> for dotnet ef from an environment variable plus an optional fallback connection string, so each package's IDesignTimeDbContextFactory stays a one-liner.
• PostgresHealth.CheckAsync. Yields a Lyo.Health HealthResult from either an IDbContextFactory<TContext> or a live DbContext, and reports the schema under the database metadata key.
• AddPostgresDbContextFactory<TContext, TOptions>(options). Registers the options instance plus a pooled-style IDbContextFactory<TContext> bound to that options' connection string and schema.

Examples

Usage

using Lyo.Postgres;
using Microsoft.Extensions.DependencyInjection;

public sealed class AuditDbOptions : IPostgresMigrationConfig
{
    public string ConnectionString { get; init; } = "";
    public bool EnableAutoMigrations { get; init; }
    public string Schema { get; init; } = "audit";
}

services.Configure<AuditDbOptions>(configuration.GetSection("Audit:Postgres"));
services.AddPostgresMigrations<AuditDbContext, AuditDbOptions>();

Types

The hosted service activates a TContext instance via Activator.CreateInstance(typeof(TContext), dbContextOptions), so each consumer DbContext must expose a public constructor that takes a single DbContextOptions<TContext>. The migrations history table is stored in the schema returned by IPostgresMigrationConfig.Schema as "<schema>"."__EFMigrationsHistory".

StartAsync short-circuits when EnableAutoMigrations is false. If the flag is true, both ConnectionString and Schema are required (whitespace throws via Lyo.Exceptions.ArgumentHelpers).

Usage

• The hosted service resolves IOptions<AuditDbOptions>.
• When EnableAutoMigrations is false, it returns immediately.
• Otherwise it builds an AuditDbContext with UseNpgsql(connectionString, opt => opt.MigrationsHistoryTable("__EFMigrationsHistory", schema)).
• It runs CREATE SCHEMA IF NOT EXISTS "<schema>" (the schema name is escaped by doubling embedded " characters before interpolation).
• Then it runs Database.MigrateAsync(ct).

Consumers

• Lyo.Audit.Postgres
• Lyo.Email.Postgres
• Lyo.ChangeTracker.Postgres
• Lyo.EntityReference.Postgres
• Lyo.FileMetadataStore.Postgres

Dependencies

Generated from ProjectReference / PackageReference (same model as docs/Lyo.ProjectGraph.html).

• Lyo.Exceptions (direct, lyo)
• Lyo.Health (direct, lyo)
• Microsoft.EntityFrameworkCore 10.0.5 (direct, microsoft)
• Microsoft.EntityFrameworkCore.Design 10.0.5 (direct, microsoft)
• Microsoft.EntityFrameworkCore.Relational 10.0.5 (direct, microsoft)
• Microsoft.Extensions.Hosting.Abstractions 10.0.5 (direct, microsoft)
• Microsoft.Extensions.Options 10.0.5 (direct, microsoft)
• Npgsql.EntityFrameworkCore.PostgreSQL 10.0.3 (direct, third-party)