raft: add a raft tracing library

This change adds a tracing library for raft messages. Specifically it
allows registering an entry either directly or due to a remote raft
message and then possibly tracing the message at various key points.
When the message is finally unregistered, it will dump the trace to the
log. Additionally, on a local message, it will add the trace to the
context that is passed in.

Fixes: cockroachdb#104035

Release note: None

pkg/BUILD.bazel

@@ -269,6 +269,7 @@ ALL_TESTS = [
     "//pkg/kv/kvserver/protectedts:protectedts_test",
     "//pkg/kv/kvserver/raftentry:raftentry_test",
     "//pkg/kv/kvserver/raftlog:raftlog_test",
+    "//pkg/kv/kvserver/rafttrace:rafttrace_test",
     "//pkg/kv/kvserver/raftutil:raftutil_test",
     "//pkg/kv/kvserver/rangefeed:rangefeed_test",
     "//pkg/kv/kvserver/rangelog:rangelog_test",
@@ -1513,6 +1514,8 @@ GO_TARGETS = [
     "//pkg/kv/kvserver/raftentry:raftentry_test",
     "//pkg/kv/kvserver/raftlog:raftlog",
     "//pkg/kv/kvserver/raftlog:raftlog_test",
+    "//pkg/kv/kvserver/rafttrace:rafttrace",
+    "//pkg/kv/kvserver/rafttrace:rafttrace_test",
     "//pkg/kv/kvserver/raftutil:raftutil",
     "//pkg/kv/kvserver/raftutil:raftutil_test",
     "//pkg/kv/kvserver/rangefeed:rangefeed",

pkg/kv/kvserver/rafttrace/BUILD.bazel

@@ -0,0 +1,38 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "rafttrace",
+    srcs = ["rafttrace.go"],
+    importpath = "github.com/cockroachdb/cockroach/pkg/kv/kvserver/rafttrace",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//pkg/kv/kvpb",
+        "//pkg/kv/kvserver/kvserverpb",
+        "//pkg/raft",
+        "//pkg/raft/raftpb",
+        "//pkg/settings",
+        "//pkg/settings/cluster",
+        "//pkg/util/log",
+        "//pkg/util/syncutil",
+        "//pkg/util/tracing",
+        "//pkg/util/tracing/tracingpb",
+        "@com_github_cockroachdb_logtags//:logtags",
+        "@com_github_cockroachdb_redact//:redact",
+    ],
+)
+
+go_test(
+    name = "rafttrace_test",
+    srcs = ["rafttrace_test.go"],
+    embed = [":rafttrace"],
+    deps = [
+        "//pkg/kv/kvpb",
+        "//pkg/kv/kvserver/kvserverpb",
+        "//pkg/raft/raftpb",
+        "//pkg/settings/cluster",
+        "//pkg/testutils",
+        "//pkg/util/tracing",
+        "//pkg/util/tracing/tracingpb",
+        "@com_github_stretchr_testify//require",
+    ],
+)