features: Introduce enterprise_features

- features::license_required_feature

Enumeration of redpanda features that require an enterprise license.

- features::enterprise_feature_report

A thin wrapper around a couple of sets to account for the status of
enterprise features (usually based on cluster configs).

Signed-off-by: Oren Leiman <oren.leiman@redpanda.com>

src/v/features/BUILD

@@ -34,3 +34,20 @@ redpanda_cc_library(
         "@seastar",
     ],
 )
+
+redpanda_cc_library(
+    name = "enterprise_features",
+    srcs = [
+        "enterprise_features.cc",
+    ],
+    hdrs = [
+        "enterprise_features.h",
+    ],
+    include_prefix = "features",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//src/v/base",
+        "@abseil-cpp//absl/container:flat_hash_set",
+        "@boost//:range",
+    ],
+)

src/v/features/CMakeLists.txt

@@ -14,4 +14,12 @@ v_cc_library(
 
 add_dependencies(v_features kafka_codegen_headers)
 
+v_cc_library(
+  NAME enterprise_features
+  SRCS
+    enterprise_features.cc
+  DEPS
+    absl::flat_hash_set
+)
+
 add_subdirectory(tests)

src/v/features/enterprise_features.cc

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2024 Redpanda Data, Inc.
+ *
+ * Use of this software is governed by the Business Source License
+ * included in the file licenses/BSL.md
+ *
+ * As of the Change Date specified in that file, in accordance with
+ * the Business Source License, use of this software will be governed
+ * by the Apache License, Version 2.0
+ */
+
+#include "enterprise_features.h"
+
+#include "base/vassert.h"
+
+#include <iostream>
+
+namespace features {
+
+std::ostream& operator<<(std::ostream& os, license_required_feature f) {
+    switch (f) {
+    case license_required_feature::audit_logging:
+        return os << "audit_logging";
+    case license_required_feature::cloud_storage:
+        return os << "cloud_storage";
+    case license_required_feature::partition_auto_balancing_continuous:
+        return os << "partition_auto_balancing_continuous";
+    case license_required_feature::core_balancing_continuous:
+        return os << "core_balancing_continuous";
+    case license_required_feature::gssapi:
+        return os << "gssapi";
+    case license_required_feature::oidc:
+        return os << "oidc";
+    case license_required_feature::schema_id_validation:
+        return os << "schema_id_validation";
+    case license_required_feature::rbac:
+        return os << "rbac";
+    case license_required_feature::fips:
+        return os << "fips";
+    }
+    __builtin_unreachable();
+}
+
+void enterprise_feature_report::set(
+  license_required_feature feat, bool enabled) {
+    auto insert = [feat](vtype& dest, const vtype& other) {
+        vassert(
+          !other.contains(feat),
+          "feature {{{}}} cannot be both enabled and disabled",
+          feat);
+        dest.insert(feat);
+    };
+
+    if (enabled) {
+        insert(_enabled, _disabled);
+    } else {
+        insert(_disabled, _enabled);
+    }
+}
+
+} // namespace features

src/v/features/enterprise_features.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2024 Redpanda Data, Inc.
+ *
+ * Use of this software is governed by the Business Source License
+ * included in the file licenses/BSL.md
+ *
+ * As of the Change Date specified in that file, in accordance with
+ * the Business Source License, use of this software will be governed
+ * by the Apache License, Version 2.0
+ */
+
+#pragma once
+
+#include <absl/container/flat_hash_set.h>
+#include <boost/range/iterator_range.hpp>
+
+#include <iosfwd>
+
+namespace features {
+
+enum class license_required_feature {
+    audit_logging,
+    cloud_storage,
+    partition_auto_balancing_continuous,
+    core_balancing_continuous,
+    gssapi,
+    oidc,
+    schema_id_validation,
+    rbac,
+    fips,
+};
+
+std::ostream& operator<<(std::ostream&, license_required_feature);
+
+/**
+ * Thin wrapper around two sets to indicate the current state of enterprise
+ * features in the cluster.
+ */
+class enterprise_feature_report {
+    using vtype = absl::flat_hash_set<license_required_feature>;
+    using range = boost::iterator_range<vtype::const_iterator>;
+
+public:
+    void set(license_required_feature feat, bool enabled);
+    range enabled() const { return _enabled; }
+    range disabled() const { return _disabled; }
+    bool any() const { return !_enabled.empty(); }
+
+private:
+    vtype _enabled;
+    vtype _disabled;
+};
+
+} // namespace features