Add support for connection string to Microsoft.ApplicationInsights.NLogTarget

[saidi-adot]

Add support for connection string to Microsoft.ApplicationInsights.NLogTarget #2714

Fix Issue # .

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• I ran Unit Tests locally.
• CHANGELOG.md updated with one line description of the fix, and a link to the original issue if available.

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[saidi-adot]

@TimothyMothra @cijothomas - Can you please review the PR

[cijothomas]

#2750 (comment)

[saidi-adot]

#2750 (comment)

@rajkumar-rangaraj and @TimothyMothra - Can you please let us know your thoughts on this.

[snakefoot]

Maybe implement like this:

            string connectionString = this.connectionStringLayout.Render(LogEventInfo.CreateNullEvent());

            // Check if nlog application insights target has connectionstring in config file then
            // configure new telemetryclient with the connectionstring otherwise using legacy instrumentationkey.
            if (!string.IsNullOrWhiteSpace(connectionString))
            {
                var telemetryConfiguration = TelemetryConfiguration.CreateDefault();
                telemetryConfiguration.ConnectionString = connectionString;
                this.telemetryClient = new TelemetryClient(telemetryConfiguration);
            }
            else
            {
#pragma warning disable CS0618 // Type or member is obsolete: TelemtryConfiguration.Active is used in TelemetryClient constructor.
                this.telemetryClient = new TelemetryClient();
#pragma warning restore CS0618 // Type or member is obsolete
                string instrumentationKey = this.instrumentationKeyLayout.Render(LogEventInfo.CreateNullEvent());
                if (!string.IsNullOrWhiteSpace(instrumentationKey))
                {
                    this.telemetryClient.Context.InstrumentationKey = instrumentationKey;
                }
            }

This will resolve the issue about not to modify TelemtryConfiguration.Active

[snakefoot]

@cijothomas If NLog-target changes from using obsolete/legacy TelemetryClient (depending on on TelemtryConfiguration.Active), to instead create its own local TelemetryClient using connectionString. Would you accept the pull-request ?

[snakefoot]

@cijothomas Polite poke. If NLog-target changes from using obsolete/legacy TelemetryClient (depending on on TelemtryConfiguration.Active), to instead create its own local TelemetryClient using connectionString. Would you accept the pull-request ?

[cijothomas]

@cijothomas Polite poke. If NLog-target changes from using obsolete/legacy TelemetryClient (depending on on TelemtryConfiguration.Active), to instead create its own local TelemetryClient using connectionString. Would you accept the pull-request ?

I'll let @rajkumar-rangaraj @TimothyMothra to comment on if this repo plan to accept new features, given the OTel movement.

From a technical standpoint, creating own TelemetryClient would mean it'll have a config, different from the rest of the application, right?

[snakefoot]

@cijothomas From a technical standpoint, creating own TelemetryClient would mean it'll have a config, different from the rest of the application, right?

Yes like this:

                var telemetryConfiguration = TelemetryConfiguration.CreateDefault();
                telemetryConfiguration.ConnectionString = connectionString;
                this.telemetryClient = new TelemetryClient(telemetryConfiguration);

Thus not depend on deprecated TelemtryConfiguration.Active, that requires one to explicit configure EnableActiveTelemetryConfigurationSetup to make the NLog-target work. Giving a better user-experience.