How to Customize Telemetry Property Names

Description

By default, ApplicationInsights-Kubernetes enriches all telemetry entries with Kubernetes info like the container name and so on. The format of the telemetry property names look like this:

{
    "customDimensions":
    {
        // Leading with "Kubernetes", then resource of "Container", then property of "Name".
        // The default separator is dot(".").
        "Kubernetes.Container.Name": "ai-k8s-basic-container"
        ...
    }
}

It works well for most cases, except we have a report that this format is conflicting with other systems, that doesn't work well when dot(.) is used as a separator. Refer to #222 for details.

Since there's no way for us to come up with a rule to deal with all constraints by other systems, in version 1.1.4 (or higher), there is a way to customize the telemetry keys used for Application Insights Kubernetes.

Here's the usage:

services.AddApplicationInsightsKubernetesEnricher(options =>
{
    // options.TelemetryKeyProcessor accepts a Func<string, string>. It takes in the originalkey, and returns the processed key.
    // Here we replace '.' with '_' but it could actually be any custom logic.
    options.TelemetryKeyProcessor = (key) => key.Replace('.', '_');
});

The telemetry will look like:

{
    "customDimensions":
    {
        // Kubernetes.Container.Name becomes Kubernetes_Container_Name
        "Kubernetes_Container_Name": "ai-k8s-basic-container"
        ...
    }
}

Examples:

• Remove the separator:

// Kubernetes.Container.Name becomes KubernetesContainerName
options.TelemetryKeyProcessor = (key) => key.Replace(".", "");

• Add quotes to the key:

// Kubernetes.Container.Name becomes "Kubernetes.Container.Name"
options.TelemetryKeyProcessor = (key) => $@"""{key}""";