How do I add the failureSink to elasticsearchSink

Question

I add FileSink as failureSink to ElasticsearchSink from appSettings.json. But "Cannot create instance of type 'Serilog.Core.ILogEventSink' because it is either abstract or an interface." I get an error. How do I fixed it?

"Serilog": {
    "Using": [ "Serilog.Sinks.Console", "Serilog.Sinks.Elasticsearch"],
    "MinimumLevel": {
        "Default": "Error",
        "Override": {
            "Microsoft.Hosting.Lifetime": "Information",
            "Microsoft.AspNetCore": "Warning",
            "Microsoft": "Error",
            "System": "Error",
            "Quartz": "Error",
            "GraphQL": "Warning",
            "Hateoas": "Warning",
            "MassTransit": "Information"
        }
    },
    "WriteTo": [
        {
            "Name": "Elasticsearch",
            "Args": {
                "nodeUris": "http://17.172.25.115:9200",
                "indexFormat": "logstash",
                "templateName": "logstash-template",
                "emitEventFailure":  "WriteToFailureSink, WriteToSelfLog, RaiseCallback",
                "failureSink": {
                    "type": "Serilog.Sinks.File.FileSink, Serilog.Sinks.File",
                    "path": "failures.txt",
                    "fileSizeLimitBytes":  null 
                }
            }
        },
        {
            "Name": "Console",
            "Args": {
                "theme": "Serilog.Sinks.SystemConsole.Themes.AnsiConsoleTheme::Code, Serilog.Sinks.Console",
                "outputTemplate": "[{Timestamp:HH:mm:ss} {Level:u3}] {Message:lj} <s:{SourceContext}>{NewLine}{Exception}"
            }
        }
    ],
    "Enrich": [ "FromLogContext" ],
    "Properties": {
        "ApplicationName": "AselsanSatComPAMAStatic"
    }
},

Answer 1

there are some mandatory settings in FileSink that we need to configure before the instance of FileSink can be created. You can set something like following and it should work.

  "failureSink": {
    "type": "Serilog.Sinks.File.FileSink, Serilog.Sinks.File",
    "path": "failures.txt",
    "fileSizeLimitBytes": 1234567,
    "rollingInterval": "Day",
    "textFormatter": "Serilog.Formatting.Json.JsonFormatter"
  }