export bao client-cert not_before/not_after gauges and alert past 80% of lifetime

swarm-cert-metrics/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "swarm-cert-metrics"
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+opentelemetry.workspace = true
+# The cert file's validity window.
+swarm-secret-client.workspace = true
+tracing.workspace = true
+
+[lints]
+workspace = true
+
+[dev-dependencies]
+# `InMemoryMetricExporter`, to read back what a provider exports.
+opentelemetry_sdk = { workspace = true, features = ["testing"] }