ILogger sink for Azure Serverless Functions - azure

Question

I am injecting ILogger into my Azure functions, and in my host.json I have the following:
{
"version": "2.0",
"logging": {
"applicationInsights": {
"samplingSettings": {
"isEnabled": true,
"maxTelemetryItemsPerSecond": 20
}
}
}
}
I then log as below:
public class EnrollmentFunctions
{
private readonly ILogger<AttestationFunctions> logger;
public EnrollmentFunctions(ILogger<AttestationFunctions> log)
{
logger = log;
}
public async Task<IActionResult> Enroll(
[HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = "enroll")] HttpRequest req)
{
logger.LogInformation("Requesting attestation of device name {deviceName}.", req.Query["deviceName"]);
}
}
However no logs are logged as below - appreciate pointers as to what I am doing wrong and where I would see my logs please.

Answer 1

I've followed the below work around to achieve the desired results as described:
I've used generalized logging in my function project using Visual studio and included both ILogger and TelemetryClient in a class Genlog.cs
Genlog.cs
public class Genlog
{
public Genlog(ILogger<Genlog> logger, TelemetryClient telemetry)
{
Logger = logger ?? throw new ArgumentNullException(nameof(logger));
Telemetry = telemetry ?? throw new ArgumentNullException(nameof(telemetry));
}
public void testlog(string mylog)
{
Logger.LogInformation("TestCustomInformationLog:" + mylog);
Telemetry.TrackTrace("TestCustomTraceLog: " + mylog, Microsoft.ApplicationInsights.DataContracts.SeverityLevel.Information);
Telemetry.TrackException(new Exception(""));
}
public ILogger<Genlog> Logger { get; }
public TelemetryClient Telemetry { get; }
}
Startup.cs
#Adding configuring service of Genlog in startup.cs
public override void Configure(IFunctionsHostBuilder builder)
{
builder.Services.AddScoped<Genlog>();
}
Function.cs
public class Function1
{
private readonly Genlog genlog;
public Function1(Genlog genlog)
{
this.genlog = genlog ?? throw new ArgumentNullException(nameof(genlog));
}
[FunctionName("Function1")]
public async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
ILogger log)
{
log.LogInformation("C# HTTP trigger function processed a request.");
# Using Both Ilogger & Telemetry logger in same class.
genlog.testlog("C# HTTP trigger function processed a request.");
string name = req.Query["name"];
string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
dynamic data = JsonConvert.DeserializeObject(requestBody);
name = name ?? data?.name;
string responseMessage = string.IsNullOrEmpty(name)
? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."
: $"Hello, {name}. This HTTP triggered function executed successfully.";
genlog.testlog(responseMessage);
return new OkObjectResult(responseMessage);
}
}
Result
Published to Azure to check & retrieve logs: