Serilog filter in appsettings.json not working

Question

I'm tryign to implement a log filter using serilog-expressions in my appsettings, filtering all 'health' related logs. This is my config so far:

"Serilog": {
  "Using": [ "Serilog.Sinks.MSSqlServer" ],
  "MinimumLevel": "Debug",
  "WriteTo": [
    {
      "Name": "MSSqlServer",
      "Args": {
        "connectionString": "Data Source=XXX; Database=YYY; Integrated Security=True; TrustServerCertificate=true;",
        "sinkOptionsSection": {
          "tableName": "Logging",
          "autoCreateSqlDatabase": false,
          "autoCreateSqlTable": true
        },
        "columnOptionsSection": {
          "additionalColumns": [
            {
              "columnName": "RequestMethod",
              "dataLength": "8"
            },
            {
              "columnName": "StatusCode",
              "dataType": "Int"
            }
          ]
        },
        "Filter": [
          {
            "Name": "ByExcluding",
            "Args": {
              "expression": "RequestPath like '%/health%'"
            }
          }
        ]
      }
    }
  ],
  "Enrich": [ "FromLogContext", "WithMachineName", "WithThreadId" ],
  "Destructure": [
    {
      "Name": "ToMaximumDepth",
      "Args": { "maximumDestructuringDepth": 4 }
    },
    {
      "Name": "ToMaximumStringLength",
      "Args": { "maximumStringLength": 100 }
    },
    {
      "Name": "ToMaximumCollectionCount",
      "Args": { "maximumCollectionCount": 10 }
    }
  ],
  "Properties": {
    "Application": "Api"
  }
},

However, the messages related to HealthChecks continue to be logging in my database.

How can I write a config that filter by IncludingOnly, Excluding or checks if a colum from Loggin table has a specifc value?

Thanks

I read the documentation about Serilog Expressions, but didn't quite understand how the filter works: Which properties can I use to filter? Where can I find them? Are they the variables in {KEYS} from MessageTemplate column? What about my custom columns: can I filter them?

Ex.: The message in MessageTemplate 'HTTP {RequestMethod} {RequestPath} responded {StatusCode} in {Elapsed:0.0000} ms' provides me {RequestPath} variable, but when I try to use it in a filter ( "expression": "RequestPath like '%/health%'"), nothing happens.

Answer 1

The Filter section was in the wrong place, inside the WriteTo tag. Placing it right inside "Serilog" fixed the problem.

  "Serilog": {
    "Using": [ "Serilog.Sinks.MSSqlServer" ],
    "MinimumLevel": "Information",
    "WriteTo": [
      {
        "Name": "MSSqlServer",
        "Args": {
          "connectionString": "Data Source=XXX; Database=YYY; Integrated Security=True; TrustServerCertificate=true;",
          "sinkOptionsSection": {
            "tableName": "Logging",
            "autoCreateSqlDatabase": false,
            "autoCreateSqlTable": true
          },
          "columnOptionsSection": {
            "additionalColumns": [
              {
                "columnName": "RequestMethod",
                "dataType": "nvarchar",
                "dataLength": "8"
              },
              {
                "columnName": "StatusCode",
                "dataType": "Int"
              },
              {
                "columnName": "MachineName",
                "dataType": "nvarchar",
                "dataLength": "32"
              },
              {
                "columnName": "EnvironmentName",
                "dataType": "nvarchar",
                "dataLenght": "32"
              },
              {
                "columnName": "EnvironmentUserName",
                "dataType": "nvarchar",
                "dataLenght": "32"
              },
              {
                "columnName": "ClientIp",
                "dataType": "nvarchar",
                "dataLenght": "64"
              },
              {
                "columnName": "ThreadId",
                "dataType": "int"
              },
              {
                "columnName": "ThreadName",
                "dataType": "nvarchar",
                "dataLenght": "32"
              },
              {
                "columnName": "ProcessId",
                "dataType": "int"
              },
              {
                "columnName": "ProcessName",
                "dataType": "nvarchar",
                "dataLenght": "64"
              }
            ]
          }
        }
      }
    ],
    "Filter": [
      {
        "Name": "ByExcluding",
        "Args": {
          "expression": "Contains(@m, 'health')"
        }
      },
      {
        "Name": "ByExcluding",
        "Args": {
          "expression": "Contains(@m, 'Health_Homol')"
        }
      },
      {
        "Name": "ByExcluding",
        "Args": {
          "expression": "Contains(@m, 'swagger')"
        }
      }
    ],
    "Enrich": [
      "FromLogContext",
      "WithMachineName",
      "WithEnvironmentName",
      "WithEnvironmentUserName",
      "WithThreadId",
      "WithThreadName",
      "WithClientIp",
      "WithProcessId",
      "WithProcessName"
    ],

    "Properties": {
      "Application": "Api"
    }