Loggly is a cloud based log management service. Create a new input and specify that you want to use a http input with JSON enabled. Use the loggly-csharp-configuration XML configuration syntax to configure the sink.

Package - Serilog.Sinks.Loggly | Platforms - .NET 4.5

var log = new LoggerConfiguration()
    .WriteTo.Loggly()
    .CreateLogger();

Properties will be sent along to Loggly. The level is sent as a category.

To use a durable logger (that will save messages locally if the connection to the server is unavailable, and resend once the connection has recovered), set the bufferBaseFilename argument in the Loggly() extension method.

var log = new LoggerConfiguration()
    .WriteTo.Loggly(bufferBaseFilename:@"C:\test\buffer")
    .CreateLogger();

This will write unsent messages to a buffer-{Date}.json file in the specified folder (C:\test\ in the example).

The method also takes a retainedFileCountLimit parameter that will allow you to control how much info to store / ship when back online. By default, the value is null with the intent is to send all persisted data, no matter how old. If you specify a value, only the data in the last N buffer files will be shipped back, preventing stale data to be indexed (if that info is no longer usefull).

The sink can also be configured from appsettings.json for .NET Standard / .NET Core applications that do not support XML configuration:

{
  "Serilog": {
    "WriteTo": [
      {
        "Name": "Loggly",
        "Args": {
          "customerToken": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
          "tags": "foo,bar"
        }
      }
    ],
    "Properties": { "Application": "SampleApp" }
  }
}

The customerToken argument is required, if you use this form of configuration. The tags argument is comma-delimited. The Application property will also be sent to Loggly and should be set appropriately.