[v24.2.x] CORE-7338 license: add metric

src/v/features/BUILD

@@ -14,6 +14,9 @@ redpanda_cc_library(
         "fwd.h",
         "logger.h",
     ],
+    implementation_deps = [
+        "//src/v/metrics",
+    ],
     include_prefix = "features",
     visibility = ["//visibility:public"],
     deps = [

src/v/features/CMakeLists.txt

@@ -10,6 +10,8 @@ v_cc_library(
     v::model
     v::config
     v::version
+    v::security
+    v::metrics
   )
 
 add_dependencies(v_features kafka_codegen_headers)

src/v/features/feature_table.cc

@@ -15,12 +15,18 @@
 #include "cluster/version.h"
 #include "config/configuration.h"
 #include "features/logger.h"
+#include "metrics/metrics.h"
+#include "metrics/prometheus_sanitize.h"
 #include "version/version.h"
 
 #include <seastar/core/abort_source.hh>
 
+#include <chrono>
+#include <memory>
+
 // The feature table is closely related to cluster and uses many types from it
 using namespace cluster;
+using namespace std::chrono_literals;
 
 namespace features {
 
@@ -206,6 +212,60 @@ static std::array test_extra_schema{
     feature_spec::prepare_policy::always},
 };
 
+class feature_table::probe {
+public:
+    explicit probe(const feature_table& parent)
+      : _parent(parent) {}
+
+    probe(const probe&) = delete;
+    probe& operator=(const probe&) = delete;
+    probe(probe&&) = delete;
+    probe& operator=(probe&&) = delete;
+    ~probe() noexcept = default;
+
+    void setup_metrics() {
+        if (ss::this_shard_id() != 0) {
+            return;
+        }
+
+        if (!config::shard_local_cfg().disable_metrics()) {
+            setup_metrics_for(_metrics);
+        }
+
+        if (!config::shard_local_cfg().disable_public_metrics()) {
+            setup_metrics_for(_public_metrics);
+        }
+    }
+
+    void setup_metrics_for(metrics::metric_groups_base& metrics) {
+        namespace sm = ss::metrics;
+
+        static_assert(
+          !std::is_move_constructible_v<feature_table>
+            && !std::is_move_assignable_v<feature_table>
+            && !std::is_copy_constructible_v<feature_table>
+            && !std::is_copy_assignable_v<feature_table>,
+          "The probe captures a reference to this");
+
+        metrics.add_group(
+          prometheus_sanitize::metrics_name("cluster:features"),
+          {
+            sm::make_gauge(
+              "enterprise_license_expiry_sec",
+              [&ft = _parent]() {
+                  return calculate_expiry_metric(ft.get_license());
+              },
+              sm::description("Number of seconds remaining until the "
+                              "Enterprise license expires"))
+              .aggregate({sm::shard_label}),
+          });
+    }
+
+    const feature_table& _parent;
+    metrics::internal_metric_groups _metrics;
+    metrics::public_metric_groups _public_metrics;
+};
+
 feature_table::feature_table() {
     // Intentionally undocumented environment variable, only for use
     // in integration tests.
@@ -238,9 +298,15 @@ feature_table::feature_table() {
             }
         }
     }
+
+    _probe = std::make_unique<probe>(*this);
+    _probe->setup_metrics();
 }
 
+feature_table::~feature_table() noexcept = default;
+
 ss::future<> feature_table::stop() {
+    _probe.reset();
     _as.request_abort();
 
     // Don't trust callers to have fired their abort source in the right
@@ -703,6 +769,18 @@ void feature_table::assert_compatible_version(bool override) {
     }
 }
 
+long long feature_table::calculate_expiry_metric(
+  const std::optional<security::license>& license,
+  security::license::clock::time_point now) {
+    if (!license) {
+        return -1;
+    }
+
+    auto rem = license->expiration() - now;
+    auto rem_capped = std::max(rem.zero(), rem);
+    return rem_capped / 1s;
+}
+
 } // namespace features
 
 namespace cluster {

src/v/features/feature_table.h

@@ -17,6 +17,7 @@
 #include "utils/waiter_queue.h"
 
 #include <array>
+#include <memory>
 #include <string_view>
 #include <unordered_set>
 
@@ -497,6 +498,11 @@ class feature_table {
     static cluster::cluster_version get_earliest_logical_version();
 
     feature_table();
+    feature_table(const feature_table&) = delete;
+    feature_table& operator=(const feature_table&) = delete;
+    feature_table(feature_table&&) = delete;
+    feature_table& operator=(feature_table&&) = delete;
+    ~feature_table() noexcept;
 
     feature_state& get_state(feature f_id);
     const feature_state& get_state(feature f_id) const {
@@ -598,7 +604,15 @@ class feature_table {
     // Assert out on startup if we appear to have upgraded too far
     void assert_compatible_version(bool);
 
+    // Visible for testing
+    static long long calculate_expiry_metric(
+      const std::optional<security::license>& license,
+      security::license::clock::time_point now
+      = security::license::clock::now());
+
 private:
+    class probe;
+
     // Only for use by our friends feature backend & manager
     void set_active_version(
       cluster::cluster_version,
@@ -654,6 +668,7 @@ class feature_table {
 
     ss::gate _gate;
     ss::abort_source _as;
+    std::unique_ptr<probe> _probe;
 };
 
 } // namespace features

src/v/features/tests/BUILD

@@ -0,0 +1,17 @@
+load("//bazel:test.bzl", "redpanda_cc_btest")
+
+redpanda_cc_btest(
+    name = "feature_table_test",
+    timeout = "short",
+    srcs = [
+        "feature_table_test.cc",
+    ],
+    deps = [
+        "//src/v/cluster:features",
+        "//src/v/features",
+        "//src/v/security:license",
+        "//src/v/test_utils:seastar_boost",
+        "@seastar",
+        "@seastar//:testing",
+    ],
+)

src/v/features/tests/feature_table_test.cc

@@ -9,10 +9,10 @@
  * by the Apache License, Version 2.0
  */
 
-#include "base/vlog.h"
 #include "cluster/feature_update_action.h"
 #include "features/feature_table.h"
 #include "features/feature_table_snapshot.h"
+#include "security/license.h"
 #include "test_utils/fixture.h"
 
 #include <seastar/core/sleep.hh>
@@ -335,3 +335,25 @@ FIXTURE_TEST(feature_table_old_snapshot, feature_table_fixture) {
       ft.get_state(feature::test_alpha).get_state()
       == feature_state::state::active);
 }
+
+SEASTAR_THREAD_TEST_CASE(feature_table_probe_expiry_metric_test) {
+    using ft = features::feature_table;
+    const char* sample_valid_license = std::getenv("REDPANDA_SAMPLE_LICENSE");
+    if (sample_valid_license == nullptr) {
+        const char* is_on_ci = std::getenv("CI");
+        BOOST_TEST_REQUIRE(
+          !is_on_ci,
+          "Expecting the REDPANDA_SAMPLE_LICENSE env var in the CI "
+          "enviornment");
+        return;
+    }
+    const ss::sstring license_str{sample_valid_license};
+    const auto license = security::make_license(license_str);
+
+    auto expiry = security::license::clock::time_point{4813252273s};
+
+    BOOST_CHECK_EQUAL(ft::calculate_expiry_metric(license, expiry - 1s), 1);
+    BOOST_CHECK_EQUAL(ft::calculate_expiry_metric(license, expiry), 0);
+    BOOST_CHECK_EQUAL(ft::calculate_expiry_metric(license, expiry + 1s), 0);
+    BOOST_CHECK_EQUAL(ft::calculate_expiry_metric(std::nullopt), -1);
+}

src/v/security/license.cc

@@ -18,6 +18,11 @@
 #include "json/validator.h"
 #include "utils/base64.h"
 
+#include <algorithm>
+#include <chrono>
+
+using namespace std::chrono_literals;
+
 namespace security {
 
 namespace crypto {
@@ -178,9 +183,11 @@ license make_license(const ss::sstring& raw_license) {
 }
 
 bool license::is_expired() const noexcept {
-    const auto now = std::chrono::duration_cast<std::chrono::seconds>(
-      std::chrono::system_clock::now().time_since_epoch());
-    return now > expiry;
+    return clock::now() > expiration();
+}
+
+license::clock::time_point license::expiration() const noexcept {
+    return clock::time_point{expiry};
 }
 
 } // namespace security

src/v/security/license.h

@@ -21,6 +21,7 @@
 
 #include <fmt/core.h>
 
+#include <chrono>
 #include <exception>
 #include <fstream>
 #include <vector>
@@ -67,6 +68,8 @@ inline std::ostream& operator<<(std::ostream& os, license_type lt) {
 
 struct license
   : serde::envelope<license, serde::version<1>, serde::compat_version<0>> {
+    using clock = std::chrono::system_clock;
+
     /// Expected encoded contents
     uint8_t format_version;
     license_type type;
@@ -84,6 +87,9 @@ struct license
     /// Seconds since epoch until license expiration
     std::chrono::seconds expires() const noexcept;
 
+    /// Expiration timepoint
+    clock::time_point expiration() const noexcept;
+
     auto operator<=>(const license&) const = delete;
 
 private:

src/v/security/tests/license_test.cc

@@ -13,6 +13,11 @@
 #include <boost/filesystem/operations.hpp>
 #include <boost/filesystem/path.hpp>
 #include <boost/test/unit_test.hpp>
+
+#include <chrono>
+
+using namespace std::chrono_literals;
+
 namespace security {
 
 BOOST_AUTO_TEST_CASE(test_license_invalid_signature) {
@@ -76,7 +81,10 @@ BOOST_AUTO_TEST_CASE(test_license_valid_content) {
     BOOST_CHECK_EQUAL(license.format_version, 0);
     BOOST_CHECK_EQUAL(license.type, license_type::enterprise);
     BOOST_CHECK_EQUAL(license.organization, "redpanda-testing");
+    BOOST_CHECK(!license.is_expired());
     BOOST_CHECK_EQUAL(license.expiry.count(), 4813252273);
+    BOOST_CHECK(
+      license.expiration() == license::clock::time_point{4813252273s});
     BOOST_CHECK_EQUAL(
       license.checksum,
       "2730125070a934ca1067ed073d7159acc9975dc61015892308aae186f7455daf");

src/v/storage/tests/segment_deduplication_test.cc

@@ -7,6 +7,7 @@
 // the Business Source License, use of this software will be governed
 // by the Apache License, Version 2.0
 
+#include "config/configuration.h"
 #include "gmock/gmock.h"
 #include "random/generators.h"
 #include "storage/chunk_cache.h"
@@ -158,6 +159,17 @@ TEST(FindSlidingRangeTest, TestCollectOneRecordSegments) {
 }
 
 TEST(BuildOffsetMap, TestBuildSimpleMap) {
+    ss::smp::invoke_on_all([] {
+        config::shard_local_cfg().disable_metrics.set_value(true);
+        config::shard_local_cfg().disable_public_metrics.set_value(true);
+    }).get();
+    auto defer_config_reset = ss::defer([] {
+        ss::smp::invoke_on_all([] {
+            config::shard_local_cfg().disable_metrics.reset();
+            config::shard_local_cfg().disable_public_metrics.reset();
+        }).get();
+    });
+
     storage::disk_log_builder b;
     build_segments(b, 3);
     auto cleanup = ss::defer([&] { b.stop().get(); });

src/v/storage/tests/storage_test_fixture.h

@@ -209,9 +209,14 @@ class storage_test_fixture {
           resources,
           feature_table) {
         configure_unit_test_logging();
-        // avoid double metric registrations
+        // avoid double metric registrations - disk_log_builder and other
+        // helpers also start a feature_table and other structs that register
+        // metrics
         ss::smp::invoke_on_all([] {
             config::shard_local_cfg().get("disable_metrics").set_value(true);
+            config::shard_local_cfg()
+              .get("disable_public_metrics")
+              .set_value(true);
             config::shard_local_cfg()
               .get("log_segment_size_min")
               .set_value(std::optional<uint64_t>{});
@@ -230,6 +235,7 @@ class storage_test_fixture {
         feature_table.stop().get();
         ss::smp::invoke_on_all([] {
             config::shard_local_cfg().get("disable_metrics").reset();
+            config::shard_local_cfg().get("disable_public_metrics").reset();
             config::shard_local_cfg().get("log_segment_size_min").reset();
         }).get();
     }