NATS

This health check verifies the ability to communicate with a NATS server. It relies on NATS.Client package. Latest tag for the official dockerhub image is 2.6.6.

Installation

• .NET CLI
• Package Reference
• Nuget

dotnet add package AspNetCore.Pulse.Nats --version 8.0.4

Builder Extension

public void ConfigureServices(IServiceCollection services)
{
    services
        .AddHealthChecks()
        .AddNats(options =>
        {
            options.Url = "nats://demo.nats.io:4222";
            options.CredentialsPath = "The full path to a chained credentials file.";
            options.Jwt = "The path to a user's public JWT credentials.";
            options.PrivateNKey = "The path to a file for user user's private Nkey seed.";
        });
}

Url property is NATS server url and is mandatory.
There is a demo instance nats://demo.nats.io:4222 managed by nats.io and this is the default value for the url property.
The rest of the properties in NatsOptions are optional.
Docker image produces nats://localhost:4222.
Url might also be a string containing multiple URLs to the NATS Server, e.g. nats://localhost:4222, nats://localhost:8222.

See NKeys for reference to the PrivateNKey and Jwt properties.

See Authenticating with a Credentials File for details related to the CredentialsPath property.

The setup action used by the extension method caters for all three overloads supplied by the Nats client to create a connection off of a connection factory.

namespace NATS.Client
{
    public sealed class ConnectionFactory
    {
        public IConnection CreateConnection(string url);
        public IConnection CreateConnection(string url, string credentialsPath);
        public IConnection CreateConnection(string url, string jwt, string privateNkey);
    }
}

Like all IHealthChecksBuilder extensions, all the following parameters have type default values and may be overridden:

• name: The health check name. Default if not specified is nats.
• failureStatus: The HealthStatus that should be reported when the health check fails. Default is HealthStatus.Unhealthy.
• tags: A list of tags that can be used to filter sets of health checks.
• timeout: A System.TimeSpan representing the timeout of the check.