Spring Boot Provider

This provider exists for interoperability with Spring Boot environment variables and command-line arguments.

The Steeltoe Spring Boot configuration provider reads the JSON in the SPRING_BOOT_APPLICATION environment variable and adds its contents to the configuration. It does the same for command-line arguments. In both cases, any . delimiters in configuration keys are converted to :, which is the configuration key separator used by .NET. Likewise, Spring array syntax, such as [1], is converted to .NET array syntax :1.

Using the Spring Boot Provider

You should have a good understanding of how the .NET Configuration System works before starting to use this provider.

To use the Steeltoe Spring Boot provider:

1. Add the appropriate NuGet package reference to your project.
2. Add the provider to the Configuration Builder.
3. Access keys from the IConfiguration.

Add NuGet Reference

To use the provider, add a reference to the Steeltoe.Configuration.SpringBoot NuGet package.

Add Configuration Provider

To access Spring Boot configuration data, add the Spring Boot provider to the ConfigurationBuilder.

See the following example:

using Steeltoe.Configuration.SpringBoot;

var builder = WebApplication.CreateBuilder(args);
builder.Configuration.AddSpringBootFromEnvironmentVariable();
builder.Configuration.AddSpringBootFromCommandLine(args);

Access Spring Boot Data

After the configuration has been built, you can use the Spring Boot provider to access Spring-style keys in .NET syntax. For example:

using Steeltoe.Configuration.SpringBoot;

Environment.SetEnvironmentVariable("SPRING_APPLICATION_JSON", """
{
    "foo.bar": "value1"
}
""");

args = ["spring.bar[0].foo=value2"];

var builder = WebApplication.CreateBuilder(args);
builder.Configuration.AddSpringBootFromEnvironmentVariable();
builder.Configuration.AddSpringBootFromCommandLine(args);

string? value1 = builder.Configuration["foo:bar"];
string? value2 = builder.Configuration["spring:bar:0:foo"];