Serilog.Destructure.NamedValuesHandler 0.2.0-alpha

Serilog.Destructure.NamedValuesHandler

Work In Progress. No guaranties.

ToDos

• Investigate how Serilog handles system values(string, DateTime, etc.) at destructuring
• Resolve todos in code

Idea

You use Serilog and structured logging in your project.

You want to mask or even omit some special values from properties of your log events.

This package was created exactly for these purposes.

Usage

Log Example

So you have an object to log:

var user = new User
{
    Name = "John Watson",
    Email = "dr.john.h.watson@johnwatsonblog.co.uk",
    Age = 42,
};

We do want to mask doctor's email for whatever reason, but we want to keep some part of that information. Let's setup logger so we could see just the latest 7 characters of the email:

var logger = new LoggerConfiguration()
    .WriteTo.Console()
    .HandleValues(p => p
        .Mask("email", visibleCharsAmount:7)
    )
    .CreateLogger();

And then let's check how it logs this object:

logger.Information("Logged User: {@User}", user);

[01:36:10 INF] Logged User: {"Name": "John Watson", "Email": "******************************g.co.uk", "Age": 42}

But we may have more complex situation. For example, we still want to see at least a domain name.

Let's change mask handling:

.HandleValues(p => p
    .Handle<string>(
      "email",
      value => string.IsNullOrWhiteSpace(value)
          ? value
          : $"*****@{value.Split("@").Last()}")
    )
)

Now we have only domain name in a log message:

[01:43:25 INF] Logged User: {"Name": "John Watson", "Email": "*****@johnwatsonblog.co.uk", "Age": 42}

We can also omit some values so they disappear from log message:

.HandleValues(p => p
    .Omit("email", "age")
)

[01:49:19 INF] Logged User: {"Name": "John Watson"}