Inject the Datadog OpenFeature provider with the Java agent

[leoromanovsky]

Motivation

Customers using SSI should not need to add the Datadog provider dependency or provider bootstrap code to their applications. Loading the Java agent must be sufficient to connect an application that only uses the OpenFeature SDK to the Feature Flagging runtime, including when tracing is disabled. At the same time, applications that have selected another provider must not be overwritten.

Changes

This change adds OpenFeature SDK instrumentation that installs the Datadog provider on the first OpenFeature API access when Feature Flagging has been explicitly configured. It adds Feature Flagging as an instrumentation target system so the module is included in the production instrumenter index, makes the Feature Flagging bootstrap gateway available to injected helpers, and records the OpenFeature instrumentation kill switch. JUnit 5 coverage verifies injection with tracing disabled, preservation of an application provider, absence of injection without Feature Flagging configuration, and the integration kill switch.

Decisions

Injection replaces only the SDK built-in no-op provider and is enabled only when a Feature Flagging setting is explicit and resolves to enabled. This prevents the Java agent from changing unrelated OpenFeature applications. The agent runtime remains the single owner in SSI mode; the provider reuses its gateway and configuration path instead of starting the standalone runtime. The module targets OpenFeature SDK 1.20.1 through the next major version and is guarded by Muzzle.

[datadog-prod-us1-4]

🎯 Code Coverage (details)
• Patch Coverage: 0.00%
• Overall Coverage: 58.59% (-19.83%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 6b47adb | Docs | View more details | Give us feedback!}

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	13.99 s	13.99 s	[-0.8%; +0.8%] (no difference)
startup:insecure-bank:tracing:Agent	13.01 s	12.91 s	[-0.0%; +1.5%] (no difference)
startup:petclinic:appsec:Agent	16.98 s	16.74 s	[+0.6%; +2.3%] (maybe worse)
startup:petclinic:iast:Agent	16.88 s	16.94 s	[-1.0%; +0.4%] (no difference)
startup:petclinic:profiling:Agent	16.65 s	16.97 s	[-3.0%; -0.7%] (maybe better)
startup:petclinic:sca:Agent	16.71 s	16.44 s	[+0.7%; +2.6%] (maybe worse)
startup:petclinic:tracing:Agent	16.11 s	16.12 s	[-0.7%; +0.7%] (no difference)

Commit: 6b47adb9 · CI Pipeline · Benchmarking Platform UI

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