Migrate from Application Insights instrumentation keys to connection strings

[cbismuth]

On 31 March 2025, technical support for instrumentation key–based global ingestion in the Application Insights feature of Azure Monitor will end.

How can we use connection strings with Micrometer?

micrometer/implementations/micrometer-registry-azure-monitor/src/main/java/io/micrometer/azuremonitor/AzureMonitorConfig.java

Lines 42 to 44 in a350afa

	default String instrumentationKey() {
	return getSecret(this, "instrumentationKey").get();
	}

https://azure.microsoft.com/en-us/updates/technical-support-for-instrumentation-key-based-global-ingestion-in-application-insights-will-end-on-31-march-2025/

Thanks,
Christophe

[jonatan-ivanov]

Connected issue: #3420

Right now you need to override the AzureMonitorMeterRegistry but since the connection string is available in the Azure SDK (2.x), I think adding this should not be too complicated.
I think we can add a new config method for connectionString, if its value present, we can set it as-is; if its value is not present, we can create a connection string from the instrumentationKey (no endpoint override in that case). What do you think?
Would you be interested in creating a PR?

[cbismuth]

Yes @jonatan-ivanov, I'll have a look and let you know, thank you.

[cbismuth]

Hi, here is a first PR draft below, feel free to comment, thanks!

Fixed by #3715.