How can I use Application Insights locally with Azure Functions?

Question

I'm using the interface ILogger to log events inside my Azure functions. I can publish it in Azure and connect it to Application Insights in Azure.

I want to see my logs inside Application Insights in my Visual Studio during development. In here I can see this is possible in a ASP.NET Core Web Application putting some code in Startup.cs. Is something similar possible with Azure Functions using the new project template from the tooling in VS 2017?

I'm using VS 2017 and Azure Function CLI 1.0.0-beta-100.

As far as I know, if you want to log information to the Application Insights. I suggest you could consider using Microsoft.ApplicationInsights package and create the TelemetryClient with InstrumentationKey. More details, you could refer to this article. — Brando Zhang
The referenced article says itself is obsolete because Azure Functions already have integration with Application Insights. But that integration doesn't work in Visual Studio, to see the logs in VS and not the portal. — gabomgp

Brando Zhang Brando Zhang · Accepted Answer · 2017-08-09T07:58:44

As far as I know, currently we couldn't directly include the Application Insights in your local azure function project.

Here is a workaround:

You need implement it by yourself. After installed the Microsoft.ApplicationInsights from the Nuget package manager.

Then use TelemetryClient to send the logs to the azure.

More details, you could refer to below codes:

[FunctionName("HttpTriggerCSharp")]
public static async Task<HttpResponseMessage> Run([HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)]HttpRequestMessage req, TraceWriter log)
{
    var appInsights = GetTelemetryClient();
    //track an event
    appInsights.TrackEvent("I am starting now. I'm timer triggered");
    // track a numeric value
    appInsights.TrackMetric("Ticks based on current time", DateTime.Now.Ticks);
    // track an exception
    appInsights.TrackException(new Exception($"Random exception at {DateTime.Now}"));

    // send data to azure
    appInsights.Flush();

    log.Info($"C# Timer trigger function executed at: {DateTime.Now}");

    log.Info("C# HTTP trigger function processed a request.");

    // parse query parameter
    string name = req.GetQueryNameValuePairs()
        .FirstOrDefault(q => string.Compare(q.Key, "name", true) == 0)
        .Value;

    // Get request body
    dynamic data = await req.Content.ReadAsAsync<object>();

    // Set name to query string or body data
    name = name ?? data?.name;

    return name == null
        ? req.CreateResponse(HttpStatusCode.BadRequest, "Please pass a name on the query string or in the request body")
        : req.CreateResponse(HttpStatusCode.OK, "Hello " + name);
}

private static TelemetryClient GetTelemetryClient()
{
    var telemetryClient = new TelemetryClient();
    telemetryClient.InstrumentationKey = "Your InstrumentationKey";
    return telemetryClient;
}

Result:

How can I use Application Insights locally with Azure Functions?

3 Answers