Configuration

The .NET client reads its connection string from configuration. A typical setup binds the Cratis:Chronicle section of appsettings.json and registers Chronicle on the host with AddCratisChronicle.

appsettings.json:

{
  "Cratis": {
    "Chronicle": {
      "ConnectionString": "chronicle://localhost:35000"
    }
  }
}

Note

For local development, chronicle://localhost:35000 can be used without credentials. The .NET client automatically attempts development credentials.

Program.cs:

C#

using Microsoft.Extensions.Hosting;

public static class ConnectionStringsConfigurationRegistration
{
    public static void Configure(string[] args)
    {
        var builder = Host.CreateApplicationBuilder(args);

        builder.AddCratisChronicle(options => options.EventStore = "my-store");
    }
}

Kotlin

import io.cratis.chronicle.ChronicleClient
import io.cratis.chronicle.ChronicleOptions

// Kotlin has no appsettings.json-style configuration binding — read the connection string from
// wherever the application keeps its configuration (here, an environment variable) and pass it
// straight to the client.
fun createClientFromEnvironment(): ChronicleClient {
    val connectionString = System.getenv("CHRONICLE_CONNECTION_STRING") ?: "chronicle://localhost:35000"
    return ChronicleClient(ChronicleOptions.fromConnectionString(connectionString))
}

Java

import io.cratis.chronicle.ChronicleOptions;
import io.cratis.chronicle.java.BlockingChronicleClient;

// Java has no appsettings.json-style configuration binding — read the connection string from
// wherever the application keeps its configuration (here, an environment variable) and pass it
// straight to the client.
class ConnectionStringsConfigurationRegister {
    BlockingChronicleClient create() {
        String connectionString = System.getenv("CHRONICLE_CONNECTION_STRING");
        if (connectionString == null) {
            connectionString = "chronicle://localhost:35000";
        }
        return BlockingChronicleClient.connect(ChronicleOptions.fromConnectionString(connectionString));
    }
}

Elixir

defmodule MyApp.ConnectionStringsConfigurationRegistration do
  @moduledoc false

  def start_link do
    children = [
      {Chronicle.Client, event_store: "my-store"}
    ]

    Supervisor.start_link(children, strategy: :one_for_one)
  end
end

TypeScript

TypeScript does not support this workflow yet.

AddCratisChronicle is an extension on the host builder — IHostApplicationBuilder for worker and console hosts, WebApplicationBuilder for ASP.NET Core. It binds the Cratis:Chronicle section automatically, so the connection string comes from configuration rather than code. See Add Chronicle to a worker service and Add Chronicle to an ASP.NET Core app for the full host setup.

Environment-specific configuration

Use per-environment configuration files to separate development and production settings:

appsettings.Development.json:

{
  "Cratis": {
    "Chronicle": {
      "ConnectionString": "chronicle://localhost:35000/?skipTlsValidation=true"
    }
  }
}

appsettings.Production.json:

{
  "Cratis": {
    "Chronicle": {
      "ConnectionString": "chronicle://clientId:clientSecret@chronicle.production.example.com:35000"
    }
  }
}

Environment variables

You can also supply the connection string via environment variables. .NET maps the __ separator onto nested configuration keys, so Cratis:Chronicle:ConnectionString becomes:

export Cratis__Chronicle__ConnectionString="chronicle://clientId:clientSecret@server.example.com:35000"

Related topics

• DotNET client usage
• ChronicleOptions reference
• TLS configuration