From 65d9655eee5bc56506e8afb5a02bd0926d90c76b Mon Sep 17 00:00:00 2001
From: Michal Maslanka <michal@redpanda.com>
Date: Fri, 29 Sep 2023 12:30:09 +0200
Subject: [PATCH] r/consensus: expose learner start offset from consensus

Signed-off-by: Michal Maslanka <michal@redpanda.com>
---
 src/v/raft/consensus.cc | 9 +++++++++
 src/v/raft/consensus.h  | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/src/v/raft/consensus.cc b/src/v/raft/consensus.cc
index c1a197b6ef021..ed8082bfdad6f 100644
--- a/src/v/raft/consensus.cc
+++ b/src/v/raft/consensus.cc
@@ -3846,4 +3846,13 @@ void consensus::upsert_recovery_state(
     }
 }
 
+std::optional<model::offset> consensus::get_learner_start_offset() const {
+    const auto& latest_cfg = _configuration_manager.get_latest();
+
+    if (latest_cfg.get_configuration_update()) {
+        return latest_cfg.get_configuration_update()->learner_start_offset;
+    }
+    return std::nullopt;
+}
+
 } // namespace raft
diff --git a/src/v/raft/consensus.h b/src/v/raft/consensus.h
index 5b7b9fffde981..ec073ebb5d93b 100644
--- a/src/v/raft/consensus.h
+++ b/src/v/raft/consensus.h
@@ -752,6 +752,8 @@ class consensus {
       model::offset leader_last_offset,
       bool already_recovering);
 
+    std::optional<model::offset> get_learner_start_offset() const;
+
     bool use_serde_configuration() const {
         return _features.is_active(features::feature::raft_config_serde);
     }