Add simple tests for local address in http

Signed-off-by: Benjamin Kilimnik <bkilimnik@pixielabs.ai>

Author: benkilimnik

src/stirling/source_connectors/socket_tracer/http_trace_bpf_test.cc

@@ -93,6 +93,10 @@ TEST_F(GoHTTPTraceTest, RequestAndResponse) {
       std::string(record_batch[kHTTPRemoteAddrIdx]->Get<types::StringValue>(target_record_idx)),
       // On IPv6 host, localhost is resolved to ::1.
       AnyOf(HasSubstr("127.0.0.1"), HasSubstr("::1")));
+  EXPECT_THAT(
+      std::string(record_batch[kHTTPLocalAddrIdx]->Get<types::StringValue>(target_record_idx)),
+      // Due to loopback, the local address is the same as the remote address.
+      AnyOf(HasSubstr("127.0.0.1"), HasSubstr("::1")));
   EXPECT_THAT(record_batch[kHTTPRespBodyIdx]->Get<types::StringValue>(target_record_idx),
               StrEq(absl::StrCat(R"({"greeter":"Hello PixieLabs!"})", "\n")));
   // This test currently performs client-side tracing because of the cluster CIDR in

src/stirling/source_connectors/socket_tracer/openssl_trace_bpf_test.cc

@@ -95,6 +95,7 @@ class Python310ContainerWrapper : public ::px::stirling::testing::Python310Conta
 struct TraceRecords {
   std::vector<http::Record> http_records;
   std::vector<std::string> remote_address;
+  std::vector<std::string> local_address;
 };
 
 template <typename TServerContainer>
@@ -126,7 +127,9 @@ class OpenSSLTraceTest : public SocketTraceBPFTestFixture</* TClientSideTracing
         ToRecordVector<http::Record>(record_batch, server_record_indices);
     std::vector<std::string> remote_addresses =
         testing::GetRemoteAddrs(record_batch, server_record_indices);
-    return {std::move(http_records), std::move(remote_addresses)};
+    std::vector<std::string> local_address =
+        testing::GetLocalAddrs(record_batch, server_record_indices);
+    return {std::move(http_records), std::move(remote_addresses), std::move(local_address)};
   }
 
   TServerContainer server_;
@@ -200,6 +203,8 @@ TYPED_TEST(OpenSSLTraceTest, ssl_capture_curl_client) {
 
   EXPECT_THAT(records.http_records, UnorderedElementsAre(EqHTTPRecord(expected_record)));
   EXPECT_THAT(records.remote_address, UnorderedElementsAre(StrEq("127.0.0.1")));
+  // Due to loopback, the local address is the same as the remote address.
+  EXPECT_THAT(records.local_address, UnorderedElementsAre(StrEq("127.0.0.1")));
 }
 
 TYPED_TEST(OpenSSLTraceTest, ssl_capture_ruby_client) {

src/stirling/source_connectors/socket_tracer/testing/protocol_checkers.h

@@ -117,6 +117,15 @@ inline std::vector<std::string> GetRemoteAddrs(const types::ColumnWrapperRecordB
   return addrs;
 }
 
+inline std::vector<std::string> GetLocalAddrs(const types::ColumnWrapperRecordBatch& rb,
+                                              const std::vector<size_t>& indices) {
+  std::vector<std::string> addrs;
+  for (size_t idx : indices) {
+    addrs.push_back(rb[kHTTPLocalAddrIdx]->Get<types::StringValue>(idx));
+  }
+  return addrs;
+}
+
 inline std::vector<int64_t> GetRemotePorts(const types::ColumnWrapperRecordBatch& rb,
                                            const std::vector<size_t>& indices) {
   std::vector<int64_t> addrs;