Plex.Extensions.Configuration 8.0.9

Plex.Extensions.Configuration

A .NET 8 library that simplifies ASP.NET Core application configuration setup. Provides a single-call builder extension that loads JSON config files, integrates Azure Key Vault or Dapr secret store, expands environment variables in config values, and a multi-format configuration value resolver with caching.

Features

• One-call startup configuration — loads appsettings.json + environment-specific overrides, clears default loggers, removes the Kestrel Server header
• Azure Key Vault integration — automatically adds Key Vault as a configuration source when KV_NAME is set
• Dapr secret store integration — bulk-fetches secrets from the Dapr sidecar when DAPR_SECRET_STORE is set
• Environment variable expansion — resolves %VAR% placeholders in JSON config values at startup
• Multi-format config resolver — searches secret-key, environment variable, colon-delimited, and raw key formats with in-memory caching

Installation

dotnet add package Plex.Extensions.Configuration

Usage

Application startup

var builder = WebApplication.CreateBuilder(args);

// Loads JSON configs, integrates secrets (Key Vault or Dapr), expands env vars
await builder.AddJsonConfigurationFilesAsync();

var app = builder.Build();

This single call handles:

1. Clears default logging providers
2. Removes the Kestrel Server response header (security hardening)
3. Loads appsettings.json (with reload-on-change)
4. Loads appsettings.{Environment}.json if it exists
5. Integrates secrets from Azure Key Vault or Dapr (non-local environments only)
6. Adds environment variables as a configuration source
7. Expands %VAR% tokens in all JSON config values

Reading configuration values

// Basic usage — searches multiple key formats automatically
string value = configuration.GetConfigValue("MyKey");

// With a default fallback
string value = configuration.GetConfigValue("MyKey", defaultValue: "fallback");

// With a custom section name (default is "AppSetting")
string value = configuration.GetConfigValue("MyKey", settingName: "CustomSection");

GetConfigValue searches for the key in this priority order:

1. In-memory cache (static ConcurrentDictionary)
2. Secret key format — AppSetting-MyKey
3. Environment variable — AppSetting__MyKey
4. Colon-delimited — AppSetting:MyKey
5. Pluralized section — AppSettings:MyKey
6. Raw key — MyKey

Resolved values are cached for subsequent lookups and have %VAR% tokens expanded automatically.

Secret Store Configuration

Azure Key Vault

Set the KV_NAME environment variable to your Key Vault name. The library uses DefaultAzureCredential for authentication.

KV_NAME=my-keyvault-name

Dapr Secret Store

Set the DAPR_SECRET_STORE environment variable to the Dapr secret store component name. Secrets are bulk-fetched from the Dapr sidecar at startup.

DAPR_SECRET_STORE=my-secret-store

Key Vault and Dapr are mutually exclusive — if DAPR_SECRET_STORE is set, it takes precedence.

Local Development

Set IsLocal=true to skip secret store integration entirely (uses only JSON files and environment variables).

Environment Variable Expansion

Config values in appsettings.json can contain %VAR% placeholders:

{
  "ConnectionStrings": {
    "Default": "Server=%DB_HOST%;Database=%DB_NAME%;User=%DB_USER%;"
  }
}

These are expanded at startup using Environment.ExpandEnvironmentVariables(). Optionally, set ENV_VARIABLES to a comma-separated list to restrict which variables are expanded.

API Reference

Dependencies

License

Plex-Solution Community Source-Available License — free for non-commercial use only.