Feature/aws v4 cloudwatch publisher

[robvangeloven]

What this PR does / why we need it:
Fixes the #18 issue

Which issue(s) this PR fixes:

Please reference the issue this PR will close: #18

Special notes for your reviewer:
I needed to fix a lot of errors locally, security warning on open telemetry package and deprecation of IWebHost in dotnet10. However I couldn't get some tests to run properly locally

Does this PR introduce a user-facing change?: No

Please make sure you've completed the relevant tasks for this PR, out of the following list:

• [x ] Code compiles correctly
• Created/updated tests
• Unit tests passing
• End-to-end tests passing
• Extended the documentation
• Provided sample for the feature

[Copilot]

Pull request overview

Fixes the CloudWatch health check publisher to be compatible with AWSSDK.CloudWatch v4 serialization rules (issue #18), and updates tests/samples to newer ASP.NET Core hosting patterns while also pinning OpenTelemetry.Api to address dependency/security warnings.

Changes:

• Remove StatisticValues initialization from CloudWatch MetricDatum when Value is used, avoiding AWS’ “mutually exclusive” parameter error.
• Update shared conformance test hosting to WebApplication/TestServer.
• Migrate multiple sample apps from Startup/WebHost to minimal hosting (Program.cs) and add an explicit OpenTelemetry.Api pin/reference.

Reviewed changes

Copilot reviewed 19 out of 21 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
test/_SHARED/TestHostHelper.cs	Minor formatting/consistency update in shared test host helper.
test/_SHARED/ConformanceTests.cs	Switch test hosting from HostBuilder/ConfigureWebHost to WebApplication + UseTestServer.
test/HealthChecks.Publisher.ApplicationInsights.Tests/HealthChecks.Publisher.ApplicationInsights.Tests.csproj	Add direct OpenTelemetry.Api reference (central version managed).
src/HealthChecks.System/DependencyInjection/SystemHealthCheckBuilderExtensions.cs	Whitespace/formatting-only adjustment.
src/HealthChecks.Publisher.CloudWatch/CloudWatchPublisher.cs	Stop sending StatisticValues alongside Value in CloudWatch metrics (core fix for #18).
samples/HealthChecks.UIAndApiCustomization/Startup.cs	Remove legacy Startup in favor of minimal hosting.
samples/HealthChecks.UIAndApiCustomization/Program.cs	Minimal hosting version of UI+API customization sample.
samples/HealthChecks.UIAndApi/Startup.cs	Remove legacy Startup in favor of minimal hosting.
samples/HealthChecks.UIAndApi/Program.cs	Minimal hosting version of UI+API sample.
samples/HealthChecks.UI.StorageProviders/Startup.cs	Remove legacy Startup in favor of minimal hosting.
samples/HealthChecks.UI.StorageProviders/Program.cs	Minimal hosting version of storage providers sample.
samples/HealthChecks.UI.Sample/Startup.cs	Remove legacy Startup in favor of minimal hosting.
samples/HealthChecks.UI.Sample/Program.cs	Minimal hosting version of UI sample.
samples/HealthChecks.UI.Oidc/Startup.cs	Remove legacy Startup in favor of minimal hosting.
samples/HealthChecks.UI.Oidc/Program.cs	Minimal hosting version of OIDC-protected UI sample.
samples/HealthChecks.UI.Branding/Startup.cs	Remove legacy Startup in favor of minimal hosting.
samples/HealthChecks.UI.Branding/Program.cs	Minimal hosting version of branding sample.
samples/HealthChecks.Sample/Startup.cs	Remove legacy Startup in favor of minimal hosting.
samples/HealthChecks.Sample/Program.cs	Minimal hosting version of general health checks sample.
samples/HealthChecks.Sample/HealthChecks.Sample.csproj	Add direct OpenTelemetry.Api reference (central version managed).
Directory.Packages.props	Central package version pin for OpenTelemetry.Api.

Comments suppressed due to low confidence (1)

src/HealthChecks.Publisher.CloudWatch/CloudWatchPublisher.cs:55

• Add a regression test for the AWS SDK v4 serialization behavior this change is addressing (MetricDatum must not include StatisticValues when Value is set). Without a test, it’s easy for a future refactor to reintroduce the InvalidParameterCombinationException that prompted issue #18.

                new MetricDatum
                {
                    Dimensions = _dimensions,
                    MetricName = "status",
                    Timestamp = utcNow,
                    Unit = StandardUnit.Count,
                    Value = (int)report.Status
                }

[Copilot]

In the minimal hosting model, calling UseRouting() without also calling UseEndpoints(...) can result in endpoints (including MapHealthChecksUI) not being executed / throwing at runtime. Either remove UseRouting() (since MapHealthChecksUI works without it here) or add UseEndpoints and map the UI endpoints inside it.

Suggested change

app.UseRouting();

[maikebing]

@copilot apply changes based on the comments in this thread

[maikebing]

@copilot HealthChecks System CI / build / build (pull_request)Failing after 35s
HealthChecks UI CI / build (pull_request)
HealthChecks UI CI / build (pull_request)Failing after 4m

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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