rabbit-configuration.md

RabbitMQ configuration

Basic configuration

To connect to a RabbitMQ server, it is necessary to instantiate IQueueService and configure it to use a desired endpoint, credentials and other valuable connection settings. IQueueService allows clients to configure queues to exchange bindings, and to consume and produce messages in different ways (sync or async, with or without delay). To add IQueueService in your application simply use the AddRabbitMqClient extension method as in the example below.

public class Startup
{
    public static IConfiguration Configuration;

    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddRabbitMqClient(Configuration.GetSection("RabbitMq"));
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
    }
}

The AddRabbitMqClient method will add an IQueueService as a singleton, but you can register it in the transient mode simply calling the AddRabbitMqClientTransient method which takes the same set of parameters.

A RabbitMQ client can be configured via a configuration section located in the appsettings.json file. This configuration section must be of a certain format and down below is an example of all configuration options used in IQueueService.

{
 "RabbitMq": {
    "HostName": "127.0.0.1",
    "Port": "5672",
    "UserName": "guest",
    "Password": "guest",
    "ClientProvidedName": "Custom connection name",
    "VirtualHost": "/",
    "AutomaticRecoveryEnabled": true,
    "TopologyRecoveryEnabled": true,
    "RequestedConnectionTimeout": 60000,
    "RequestedHeartbeat": 60,
    "InitialConnectionRetries": 5,
    "InitialConnectionRetryTimeoutMilliseconds": 200
  }
}

A RabbitMQ connection can be configured with properties:

• HostName - RabbitMQ server,
• HostNames - collection of RabbitMQ hostnames,
• TcpEndpoints - collection of AMPQ TCP endpoints,
• Port - port RabbitMQ running on,
• UserName - user that connects to the server,
• Password - password of the user that connects to the server,
• ClientProvidedName - application-specific connection name that will be displayed in the management UI if RabbitMQ server supports it,
• VirtualHost - the default virtual host,
• AutomaticRecoveryEnabled - automatic connection recovery option,
• TopologyRecoveryEnabled - topology recovery option,
• RequestedConnectionTimeout - timeout for connection attempts,
• RequestedHeartbeat - heartbeat timeout,
• InitialConnectionRetries - a number of retries which could be attempted while trying to make an initial connection,
• InitialConnectionRetryTimeoutMilliseconds - timeout in milliseconds which could be used while trying to make an initial connection.

ClientProvidedName is optional and can be null. Options VirtualHost, AutomaticRecoveryEnabled, TopologyRecoveryEnabled, RequestedConnectionTimeout, RequestedHeartbeat, InitialConnectionRetries, InitialConnectionRetryTimeoutMilliseconds are set with default values, so you can leave them.

{
 "RabbitMq": {
    "HostName": "127.0.0.1",
    "Port": "5672",
    "UserName": "guest",
    "Password": "guest"
  }
}

For high availability RabbitMQ clusters with multiple nodes you can set hosts collection with the HostNames option.

{
 "RabbitMq": {
    "HostNames": [ "hostname1", "hostname2", "hostname3" ],
    "Port": "5672",
    "UserName": "guest",
    "Password": "guest"
  }
}

Multiple nodes configuration

If nodes are running on different hosts with different ports you have an option of configuring that via TcpEndpoints.

{
 "RabbitMq": {
    "TcpEndpoints": [
      {
        "HostName": "hostname1",
        "Port": 5672
      },
      {
        "HostName": "hostname2",
        "Port": 45672
      },
      {
        "HostName": "hostname3",
        "Port": 345672
      }
    ],
    "Port": "5672",
    "UserName": "guest",
    "Password": "guest"
  }
}

There is an importance of TcpEndpoints, HostNames, HostName options. If all of them are set connection will be created using the TcpEndpoints option. The second will be the option HostNames and the HostName option is the least important between those three.

If .json configuration files unacceptable for you there is another AddRabbitMqClient extension method that takes manually created RabbitMqClientOptions configuration as a parameter. RabbitMqClientOptions is the model class used for injecting a RabbitMQ client configuration as an IOtions<T> instance so properties named the same as in the previous method.

public class Startup
{
    public static IConfiguration Configuration;

    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public void ConfigureServices(IServiceCollection services)
    {
        var configuration = new RabbitMqClientOptions
        {
           HostName = "localhost",
           Port = 5432,
           UserName = "guest",
           Password = "guest"
        };
        services.AddRabbitMqClient(configuration);
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
    }
}

There is also the AddRabbitMqClientTransient method which takes RabbitMqClientOptions.

Ssl configuration

In case you want to establish an ssl connection you can use advanced TcpEndpoints configuration. RabbitMqTcpEndpoint has following properties:

• HostName - RabbitMQ server.
• Port - tcp connection port. The default ssl port is 5671.
• SslOption - ssl options model RabbitMqSslOption.

Ssl options model RabbitMqSslOption consists of:

• ServerName - canonical server name (CA).
• CertificatePath - path to your certificate (a key store).
• CertificatePassphrase - passphrase for client certificate.
• Enabled - flag that defines if certificate should be used. The default value is true.
• AcceptablePolicyErrors - acceptable policy errors. Flags enum SslPolicyErrors. The default value is null.

The key part is to make a proper configuration - right ServerName, CertificatePath (if needed) and AcceptablePolicyErrors.

var rabbitMqConfiguration = new RabbitMqClientOptions
{
    UserName = "guest",
    Password = "guest",
    TcpEndpoints = new List<RabbitMqTcpEndpoint>
    {
        new RabbitMqTcpEndpoint
        {
            HostName = "127.0.0.1",
            Port = 5671,
            SslOption = new RabbitMqSslOption
            {
                Enabled = true,
                ServerName = "yourCA",
                CertificatePath = "/path/tp/client-key-store.p12",
                CertificatePassphrase = "yourPathPhrase",
                AcceptablePolicyErrors = SslPolicyErrors.RemoteCertificateChainErrors | SslPolicyErrors.RemoteCertificateNameMismatch
            }
        }
    }
};

The same configuration can be in appsettings.json file.

{
    "RabbitMq": {
        "TcpEndpoints": [
            {
                "HostName": "127.0.0.1",
                "Port": 5671,
                "SslOption": {
                    "Enabled": true,
                    "ServerName": "yourCA",
                    "CertificatePath": "/path/tp/client-key-store.p12",
                    "CertificatePassphrase": "yourPathPhrase",
                    "AcceptablePolicyErrors": "RemoteCertificateChainErrors, RemoteCertificateNameMismatch"
                }
            }
        ],
        "UserName": "guest",
        "Password": "guest"
    }
}

Map that configuration using standard GetSection method.

var rabbitMqConfiguration = Configuration.GetSection("RabbitMq");

Pass it to the AddRabbitMqClient extension method as always.

services.AddRabbitMqClient(rabbitMqConfiguration);

For the exchange configuration see the Next page