pub fn install() -> Result<PrometheusHandle, ProxyError>Expand description
Install the global Prometheus recorder, once per process, and return a handle that renders
the scrape payload. Safe to call more than once: OnceLock::get_or_init runs the install
exactly once even under concurrent callers, so repeat calls (e.g. from every test that builds
an crate::proxy::app) just reuse the cached handle instead of re-installing.
ยงErrors
Returns ProxyError::Internal if the first install fails (e.g. a different metrics
recorder is already installed in-process).