Serilog.Sinks.Aliyun

A Serilog sink that writes events to the Aliyun SLS.

Getting started

Install Serilog.Sinks.Aliyun-SLS into your .NET project:

> dotnet add package Serilog.Sinks.Aliyun-SLS

Point the logger to Aliyun:

Log.Logger = new LoggerConfiguration()
    .WriteTo.Aliyun("<accessKeyId>", "<accessKeySecret>", "<endpoint>", "<project>", "<logStore>")
    .CreateLogger();

And use the Serilog logging methods to associate named properties with log events:

Log.Error("Failed to log on user {ContactId}", contactId);

Then query log event properties like ContactId from the browser:

When the application shuts down, ensure any buffered events are propertly flushed to Aliyun by disposing the logger or calling Log.CloseAndFlush():

Log.CloseAndFlush();

JSON appsettings.json configuration

To use the Aliyun sink with Microsoft.Extensions.Configuration, for example with ASP.NET Core or .NET Core, use the Serilog.Settings.Configuration package. First install that package if you have not already done so:

dotnet add package Serilog.Settings.Configuration

Instead of configuring the Aliyun sink directly in code, call ReadFrom.Configuration():

var configuration = new ConfigurationBuilder()
    .AddJsonFile("appsettings.json")
    .Build();

var logger = new LoggerConfiguration()
    .ReadFrom.Configuration(configuration)
    .CreateLogger();

In your appsettings.json file, under the Serilog node, :

{
  "Serilog": {
    "WriteTo": [
      {
        "Name": "Aliyun",
        "Args": {
          "endpoint": "",
          "project": "",
          "logStore": "",
          "accessKeyId": "",
          "accessKeySecret": ""
        }
      }
    ]
  }
}

Dynamic log level control

The Aliyun sink can dynamically adjust the logging level up or down based on the level associated with an API key in Aliyun. To use this feature, create a LoggingLevelSwitch to control the MinimumLevel, and pass this in the controlLevelSwitch parameter of WriteTo.Aliyun():

var levelSwitch = new LoggingLevelSwitch();

Log.Logger = new LoggerConfiguration()
    .MinimumLevel.ControlledBy(levelSwitch)
    .WriteTo.Aliyun(... , controlLevelSwitch: levelSwitch)
    .CreateLogger();

The equivalent configuration in JSON is:

{
  "Serilog": {
    "LevelSwitches": { "$controlSwitch": "Information" },
    "MinimumLevel": { "ControlledBy": "$controlSwitch" },
    "WriteTo": [
      {
        "Name": "Aliyun",
        "Args": {}
      }
    ]
  }
}

Troubleshooting

Client-side issues

If there's no information in the ingestion log, the application was probably unable to reach the server because of network configuration or connectivity issues. These are reported to the application through Serilog's SelfLog.

Add the following line after the logger is configured to print any error information to the console:

Serilog.Debugging.SelfLog.Enable(Console.Error);

If the console is not available, you can pass a delegate into SelfLog.Enable() that will be called with each error message:

Serilog.Debugging.SelfLog.Enable(message => {
    // Do something with `message`
});