I have a .NET project whose logs are being outputted into Elastic’s Observability platform using OpenTelemetry.
When I look at the logs on the platform (Observability > Logs > Logs Explorer), they’re only displaying the property name in curly brackets instead of the actual property value. For example, I’m seeing this:
Connection id "{ConnectionId}" stopped.
Instead of:
Connection id "0HN6DP7I45OBC" stopped.
My appsettings.json looks like this:
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*",
"OpenTelemetry": {
"CollectorEndpoint": null,
"Headers": null
}
}
Do I need a LogLevel node within OpenTelemetry similar to Logging? Or is there some other configuration somewhere else in the project?
Placeholders for structured logs, in OpenTelemetry, are stored in attributes, so the output looks like the following.
LogRecord.Body: Connection id {ConnectionId} stopped.
LogRecord.Attributes (Key:Value):
ConnectionId: 0HN6DP7I45OBC
OriginalFormat (a.k.a Body): Connection id {ConnectionId} stopped.
Here is my test steps.
using Microsoft.Extensions.Logging;
using OpenTelemetry.Logs;
using System;
var builder = WebApplication.CreateBuilder(args);
builder.Logging.ClearProviders();
builder.Logging.AddOpenTelemetry(options =>
{
options.AddConsoleExporter();
});
// For checking the difference between OpenTelemetry and Default LogProvider
builder.Logging.AddConsole();
// Add services to the container.
builder.Services.AddControllersWithViews();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
app.UseExceptionHandler("/Home/Error");
// The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
app.MapGet("/", (ILogger<Program> logger) =>
{
var connectionId = "0HN6DP7I45OBC";
// method1 work
//logger.LogInformation("Connection id "+ connectionId + " stopped.");
// method2 not work
logger.LogInformation("Connection id {ConnectionId} stopped.", connectionId);
// method3 not work
//logger.LogInformation("Connection id {0} stopped.", connectionId);
Console.WriteLine(string.Format("Jason Test Connection id {0} stopped.", connectionId));
});
app.Run();
So for this issue, I suggest you can this my method1,
logger.LogInformation("Connection id "+ connectionId + " stopped.");
it can work properly.