01
Service Discovery
How do you make the interactions between your microservices reliable and failure tolerant? For starters, you need a service registry—basically a phone book for your microservices—so service consumers know exactly where to find healthy service instances. Steeltoe includes a .NET client for Netflix Eureka so your microservices can register themselves and discover other registered services.
public void ConfigureServices(IServiceCollection services)
{
...
services.AddDiscoveryClient(Configuration);
...
}
public class FortuneService : IFortuneService
{
DiscoveryHttpClientHandler _handler;
private const string RANDOM_FORTUNE_URL = "http://fortuneService/api/fortunes/random";
public FortuneService(IDiscoveryClient client)
{
_handler = new DiscoveryHttpClientHandler(client);
}
public async Task RandomFortuneAsync()
{
var client = GetClient();
return await client.GetStringAsync(RANDOM_FORTUNE_URL);
}
private HttpClient GetClient()
{
var client = new HttpClient(_handler, false);
return client;
}
} 02
Config Server
“Strict separation of config from code” has become a cloud mandate, but that begs the question, where do you put it? And once you’ve externalized your config from your app, how do you track who changed what, when? Steeltoe leverages Spring Cloud Config Server so you can store your app’s config in a centralized, version-controlled git repo and then load it at runtime.
var builder = new ConfigurationBuilder()
.SetBasePath(env.ContentRootPath)
.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
.AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
.AddEnvironmentVariables()
.AddConfigServer(env);
Configuration = builder.Build();03
Cloud Connectors
Steeltoe automatically wires up common backing services like Redis, RabbitMQ, MySQL and Postgres because no microservice is an island. And because it was built by Pivotal, Steeltoe integrates elegantly with Cloud Foundry.
public void ConfigureServices(IServiceCollection services)
{
...
services.AddMySqlConnection(Configuration);
...
}
...
public IActionResult MySqlData(
[FromServices] MySqlConnection dbConnection)
{
dbConnection.Open();
MySqlCommand cmd = new MySqlCommand("SELECT * FROM TestData;", dbConnection);
MySqlDataReader rdr = cmd.ExecuteReader();
while (rdr.Read())
{
ViewData["Key" + rdr[0]] = rdr[1];
}
rdr.Close();
dbConnection.Close();
return View();
}
}
What They're Saying
New RC1 release of @SteeltoeOSS https://t.co/q2ylxpWb0g - very cool for .NET Microservices working in a heterogeneous system
— Martin Woodward (@martinwoodward) October 17, 2016
Pretty cool to see @pivotalcf activating @NetflixOSS for .NET --check out the new Eureka client support: https://t.co/qtLv69fO4j
— James Watters (@wattersjames) July 1, 2016
Interesting update on steeltoe.io Cloud Native .NET Applications with @moredeploys @ritam & friends at @pivotal. Will be watching closely
— Fintan Ryan (@fintanr) October 10, 2016
spring cloud + iron foundry became steel toe (iron meets boot) https://t.co/s3LPkoWOKL
— Intolerant Browser (@monkchips) October 10, 2016