Serilog.Sinks.SlackMessage

Writes Serilog events to the Slack using bot api

Geting started

Create a Slack Bot and give it at least two scopes: chat:write and files:write. Than add this bot to the channel where log events will be written.

Register the sink in your C# code

Log.Logger = new LoggerConfiguration()
        .WriteTo.Slack(
          "Enter your token here",
          new SlackLogOptions
          {
            Channel = "Enter your slack channel here",
            Mentions = new Dictionary<LogEventLevel, SlackLogMention>()
            {
              {
                LogEventLevel.Error,
                new SlackLogMention
                {
                  Users = new[] { "slack_username" },
                  Channel = SlackMention.Here,
                }
              },
            },
            MaxMessageLineCount = 5,
            SendExceptionAsFile = false,
          },
          LogEventLevel.Debug
        )
        .CreateLogger();

You can also configure the sink in appsettings.json.

{
  "Serilog": {
    "WriteTo": [
      {
        "Name": "Console"
      },
      {
        "Name": "Slack",
        "Args": {
          "Token": "Enter your token here",
          "MinimumLevel": "Debug",
          "Options": {
            "Channel": "Enter your channel name here",
            "SendExceptionAsFile": false,
            "MaxMessageLineCount": 10,
            "Mentions": {
              "Debug": {
                "Users": ["some_user_name"],
                "Channel": "Here"
              }
            }
          }
        }
      }
    ]
  }
}

To do this, install the Serilog.Settings.Configuration package and register the sink in your C# code

Log.Logger = new LoggerConfiguration()
        .ReadFrom.Configuration(configuration)
        .CreateLogger();

It is important to register SelfLog before the sink registration. Otherwise you will not see errors occurred in the sink

For example:

SelfLog.Enable(Console.WriteLine);

Samples

Set the MaxMessageLineCount option to null if you want to receive all event information in one message.

    Log.Logger = new LoggerConfiguration()
        .WriteTo.Slack(
          "<TOKEN>",
          new SlackLogOptions { Channel = "<CHANNEL>", MaxMessageLineCount = null }
        )
        .CreateLogger();
    
      Log.Information(longMessage);

But it's better to set a value between 5 to 10. Long message will be cutted and full message will be sent to the thread.

    Log.Logger = new LoggerConfiguration()
        .WriteTo.Slack(
          "<TOKEN>",
          new SlackLogOptions { Channel = "<CHANNEL>", MaxMessageLineCount = 5 }
        )
        .CreateLogger();

You can notify usergroup, channel or specific users. Just set the Mentions option

      Log.Logger = new LoggerConfiguration()
        .WriteTo.Slack(
          "<TOKEN>",
          new SlackLogOptions
          {
            Channel = "<CHANNEL>", 
            Mentions = new Dictionary<LogEventLevel, SlackLogMention>()
            {
              { LogEventLevel.Error, new SlackLogMention { Channel = SlackMention.Here } },
              { LogEventLevel.Fatal, new SlackLogMention { Channel = SlackMention.Channel } },
              { LogEventLevel.Debug, new SlackLogMention { Users = new[] { "<USERNAME>" }, UserGroups = new[] { "<USER_GROUP1>" }} },
              { LogEventLevel.Warning, new SlackLogMention { UserGroups = new[] { "<USER_GROUP2>" }} },
            }
          }
        )
        .CreateLogger();

If an event contains exception, the sink always send exception to a thread. Set the SendExceptionAsFile option to false to receive exception in message body.

If you set the SendExceptionAsFile option to true, an exception will be sent as a text file (which looks prettier in our opinion)

      Log.Logger = new LoggerConfiguration()
        .WriteTo.Slack(
          "<TOKEN>",
          new SlackLogOptions { Channel = "<CHANNEL>", SendExceptionAsFile = true }
        )
        .CreateLogger();