Restore VirtualMCPServer inline telemetry fallback for Prometheus metrics - #6469
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Restore VirtualMCPServer inline telemetry fallback for Prometheus metrics#6469lorenzozanee wants to merge 1 commit into
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VirtualMCPServer with only spec.config.telemetry was silently ignored after stacklok#4819, leaving the vmcp ConfigMap without a telemetry block. Without /metrics registered the transport falls through to the MCP handler and returns 406. Restore the deprecated inline fallback when TelemetryConfigRef is unset (ref wins), log a migration warning, and keep Prometheus metrics reachable. Signed-off-by: lorenzozanee <wyz0707@proton.me>
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Summary
VirtualMCPServer inline
spec.config.telemetrywas accepted by the API but ignored by the operator after #4819, so the rendered vmcp ConfigMap had notelemetryblock. The vmcp process never registeredGET /metrics, and Prometheus scrapes hit the MCP catch-all handler returning406 Not Acceptable: Client must accept text/event-stream.normalizeTelemetrywhenTelemetryConfigRefis unset (ref still wins when both are set)V(1)deprecation warningconfig.telemetry is deprecated; migrate to spec.telemetryConfigRefTestConverter_InlineTelemetryasserts inline is applied,TestConverter_TelemetryConfigRefWinsasserts ref precedenceFixes #6276
Type of change
Test plan
task test)task test-e2e)task lint-fix)go test ./cmd/thv-operator/pkg/vmcpconfig/...- all pass including newTestConverter_InlineTelemetryandTestConverter_TelemetryConfigRefWins.API Compatibility
v1beta1API, OR theapi-break-allowedlabel is applied and the migration guidance is described above.No CRD change; restores previously documented inline path as deprecated fallback until removed.
Does this introduce a user-facing change?
Yes - Prometheus ServiceMonitors scraping VirtualMCPServer
/metricswithenablePrometheusMetricsPath: truenow succeed (HTTP 200) instead of MCP 406, without requiring migration toMCPTelemetryConfig. Users on the new path are unaffected.