fix: take into consideration that load_yaml is called more than once

Signed-off-by: Andrea Terzolo <andreaterzolo3@gmail.com>

unit_tests/falco/app/actions/test_load_config.cpp

@@ -18,17 +18,182 @@ limitations under the License.
 #include "app_action_helpers.h"
 #include "falco_test_var.h"
 
-TEST(ActionLoadConfig, check_depracated_falco_038_configs)
-{
-	auto action = falco::app::actions::load_config;
+auto action = falco::app::actions::load_config;
 
-	// todo!: remove in 0.38.0 since we don't have anymore any precedence
-	{
-		falco::app::state s;
-		s.options.conf_filename = ENGINE_SELECTION_TEST_CONFIG;
-		EXPECT_ACTION_OK(action(s));
-		EXPECT_EQ(s.config->m_modern_ebpf.m_buf_size_preset, 5);
-		EXPECT_TRUE(s.config->m_modern_ebpf.m_drop_failed_exit);
-		EXPECT_EQ(s.config->m_modern_ebpf.m_cpus_for_each_syscall_buffer, 3);
-	}
+TEST(ActionLoadConfig, check_engine_config_is_correctly_parsed)
+{
+	falco::app::state s = {};
+	s.options.conf_filename = NEW_ENGINE_CONFIG_CHANGED;
+	// TODO: understand why load_yaml is called more times
+	EXPECT_ACTION_OK(action(s));
+
+	// Check that the engine is the kmod
+	EXPECT_TRUE(s.config->m_engine_mode == engine_kind_t::KMOD);
+
+	// Check that kmod params are the ones specified in the config
+	EXPECT_EQ(s.config->m_kmod.m_buf_size_preset, 2);
+	EXPECT_FALSE(s.config->m_kmod.m_drop_failed_exit);
+
+	// Check that all other engine params are empty
+	EXPECT_TRUE(s.config->m_ebpf.m_probe_path.empty());
+	EXPECT_EQ(s.config->m_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_ebpf.m_drop_failed_exit);
+
+	EXPECT_EQ(s.config->m_modern_ebpf.m_cpus_for_each_syscall_buffer, 0);
+	EXPECT_EQ(s.config->m_modern_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_modern_ebpf.m_drop_failed_exit);
+
+	EXPECT_TRUE(s.config->m_replay.m_trace_file.empty());
+
+	EXPECT_TRUE(s.config->m_gvisor.m_config.empty());
+	EXPECT_TRUE(s.config->m_gvisor.m_root.empty());
+
+	// Check that deprecated configs are not populated since we are using
+	// the new config.
+	EXPECT_EQ(s.config->m_syscall_buf_size_preset, 0);
+	EXPECT_EQ(s.config->m_cpus_for_each_syscall_buffer, 0);
+	EXPECT_FALSE(s.config->m_syscall_drop_failed_exit);
+}
+
+// Equal to the one above but checks that the command line options are not parsed
+TEST(ActionLoadConfig, check_command_line_options_are_not_used)
+{
+	falco::app::state s;
+	s.options.modern_bpf = true;
+	s.options.conf_filename = NEW_ENGINE_CONFIG_CHANGED;
+	EXPECT_ACTION_OK(action(s));
+
+	// Check that the engine is the kmod
+	EXPECT_TRUE(s.config->m_engine_mode == engine_kind_t::KMOD);
+
+	// Check that kmod params are the ones specified in the config
+	EXPECT_EQ(s.config->m_kmod.m_buf_size_preset, 2);
+	EXPECT_FALSE(s.config->m_kmod.m_drop_failed_exit);
+
+	// Check that all other engine params are empty
+	EXPECT_TRUE(s.config->m_ebpf.m_probe_path.empty());
+	EXPECT_EQ(s.config->m_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_ebpf.m_drop_failed_exit);
+
+	EXPECT_EQ(s.config->m_modern_ebpf.m_cpus_for_each_syscall_buffer, 0);
+	EXPECT_EQ(s.config->m_modern_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_modern_ebpf.m_drop_failed_exit);
+
+	EXPECT_TRUE(s.config->m_replay.m_trace_file.empty());
+
+	EXPECT_TRUE(s.config->m_gvisor.m_config.empty());
+	EXPECT_TRUE(s.config->m_gvisor.m_root.empty());
+
+	// Check that deprecated configs are not populated since we are using
+	// the new config.
+	EXPECT_EQ(s.config->m_syscall_buf_size_preset, 0);
+	EXPECT_EQ(s.config->m_cpus_for_each_syscall_buffer, 0);
+	EXPECT_FALSE(s.config->m_syscall_drop_failed_exit);
+}
+
+TEST(ActionLoadConfig, check_kmod_with_syscall_configs)
+{
+	falco::app::state s;
+	s.options.conf_filename = NEW_ENGINE_CONFIG_UNCHANGED;
+	EXPECT_ACTION_OK(action(s));
+
+	// Check that the engine is the kmod
+	EXPECT_TRUE(s.config->m_engine_mode == engine_kind_t::KMOD);
+
+	// Kmod params should be populated with the syscall configs
+	// since the `engine` block is untouched.
+	EXPECT_EQ(s.config->m_kmod.m_buf_size_preset, 6);
+	EXPECT_TRUE(s.config->m_kmod.m_drop_failed_exit);
+
+	// Check that all other engine params are empty
+	EXPECT_TRUE(s.config->m_ebpf.m_probe_path.empty());
+	EXPECT_EQ(s.config->m_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_ebpf.m_drop_failed_exit);
+
+	EXPECT_EQ(s.config->m_modern_ebpf.m_cpus_for_each_syscall_buffer, 0);
+	EXPECT_EQ(s.config->m_modern_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_modern_ebpf.m_drop_failed_exit);
+
+	EXPECT_TRUE(s.config->m_replay.m_trace_file.empty());
+
+	EXPECT_TRUE(s.config->m_gvisor.m_config.empty());
+	EXPECT_TRUE(s.config->m_gvisor.m_root.empty());
+
+	// Check that deprecated configs are populated
+	EXPECT_EQ(s.config->m_syscall_buf_size_preset, 6);
+	EXPECT_EQ(s.config->m_cpus_for_each_syscall_buffer, 3);
+	EXPECT_TRUE(s.config->m_syscall_drop_failed_exit);
+}
+
+TEST(ActionLoadConfig, check_override_command_line_modern)
+{
+	falco::app::state s;
+	// The comman line options should be correctly applied since the
+	// config is unchanged
+	s.options.modern_bpf = true;
+	s.options.conf_filename = NEW_ENGINE_CONFIG_UNCHANGED;
+	EXPECT_ACTION_OK(action(s));
+
+	// Check that the engine is the kmod
+	EXPECT_TRUE(s.is_modern_ebpf());
+
+	// Check that the modern ebpf engine uses the default syscall configs
+	// and not the ones in the `engine` block
+	EXPECT_EQ(s.config->m_modern_ebpf.m_cpus_for_each_syscall_buffer, 3);
+	EXPECT_EQ(s.config->m_modern_ebpf.m_buf_size_preset, 6);
+	EXPECT_TRUE(s.config->m_modern_ebpf.m_drop_failed_exit);
+
+	// Kmod params should be always populated since the kmod is the default
+	EXPECT_EQ(s.config->m_kmod.m_buf_size_preset, 6);
+	EXPECT_TRUE(s.config->m_kmod.m_drop_failed_exit);
+
+	// Check that all other engine params are empty
+	EXPECT_TRUE(s.config->m_ebpf.m_probe_path.empty());
+	EXPECT_EQ(s.config->m_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_ebpf.m_drop_failed_exit);
+
+	EXPECT_TRUE(s.config->m_replay.m_trace_file.empty());
+
+	EXPECT_TRUE(s.config->m_gvisor.m_config.empty());
+	EXPECT_TRUE(s.config->m_gvisor.m_root.empty());
+
+	// Check that deprecated configs are populated
+	EXPECT_EQ(s.config->m_syscall_buf_size_preset, 6);
+	EXPECT_EQ(s.config->m_cpus_for_each_syscall_buffer, 3);
+	EXPECT_TRUE(s.config->m_syscall_drop_failed_exit);
+}
+
+TEST(ActionLoadConfig, check_override_command_line_gvisor)
+{
+	falco::app::state s;
+	// The comman line options should be correctly applied since the
+	// config is unchanged
+	s.options.gvisor_config = "config";
+	s.options.conf_filename = NEW_ENGINE_CONFIG_UNCHANGED;
+	EXPECT_ACTION_OK(action(s));
+
+	// Check that the engine is the kmod
+	EXPECT_TRUE(s.is_gvisor());
+	EXPECT_EQ(s.config->m_gvisor.m_config, "config");
+	EXPECT_TRUE(s.config->m_gvisor.m_root.empty());
+
+	// Kmod params should be always populated since the kmod is the default
+	EXPECT_EQ(s.config->m_kmod.m_buf_size_preset, 6);
+	EXPECT_TRUE(s.config->m_kmod.m_drop_failed_exit);
+
+	// Check that all other engine params are empty
+	EXPECT_TRUE(s.config->m_ebpf.m_probe_path.empty());
+	EXPECT_EQ(s.config->m_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_ebpf.m_drop_failed_exit);
+
+	EXPECT_EQ(s.config->m_modern_ebpf.m_cpus_for_each_syscall_buffer, 0);
+	EXPECT_EQ(s.config->m_modern_ebpf.m_buf_size_preset, 0);
+	EXPECT_FALSE(s.config->m_modern_ebpf.m_drop_failed_exit);
+
+	EXPECT_TRUE(s.config->m_replay.m_trace_file.empty());
+
+	// Check that deprecated configs are populated
+	EXPECT_EQ(s.config->m_syscall_buf_size_preset, 6);
+	EXPECT_EQ(s.config->m_cpus_for_each_syscall_buffer, 3);
+	EXPECT_TRUE(s.config->m_syscall_drop_failed_exit);
 }

unit_tests/falco/test_configs/new_engine_config_changed.yaml

@@ -21,31 +21,32 @@
 ################
 
 engine:
-  kind: modern-ebpf
+  kind: kmod
   kmod:
-    buf_size_preset: 4
+    buf_size_preset: 2 # changed default value
     drop_failed_exit: false
   ebpf:
     probe: /path/to/probe.o
     buf_size_preset: 4
     drop_failed_exit: false
   modern-ebpf:
-    cpus_for_each_syscall_buffer: 1
-    buf_size_preset: 5 # This should win over the other config
+    cpus_for_each_syscall_buffer: 2
+    buf_size_preset: 4
     drop_failed_exit: false
   replay:
     trace_file: /path/to/file.scap
   gvisor:
-    config: /path/to/gvisor.yaml
-    root: /gvisor/root
+    config: /path/to/gvisor_config.yaml
+    root: ""
 
 #######################################
 # Falco performance tuning (advanced) #
 #######################################
 
-syscall_buf_size_preset: 4
+# These configs should be ignored since we have changed the `engine` config
+syscall_buf_size_preset: 6
 
-syscall_drop_failed_exit: true # This should win over the other config
+syscall_drop_failed_exit: true
 
 modern_bpf:
-  cpus_for_each_syscall_buffer: 3 # Should win this 3 over the 1 in the other config
+  cpus_for_each_syscall_buffer: 7

unit_tests/falco/test_configs/new_engine_config_unchanged.yaml

@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright (C) 2023 The Falco Authors.
+#
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+################
+# Falco engine #
+################
+
+# Unchanged
+engine:
+  kind: kmod
+  kmod:
+    buf_size_preset: 4
+    drop_failed_exit: false
+  ebpf:
+    probe: /path/to/probe.o
+    buf_size_preset: 4
+    drop_failed_exit: false
+  modern-ebpf:
+    cpus_for_each_syscall_buffer: 2
+    buf_size_preset: 4
+    drop_failed_exit: false
+  replay:
+    trace_file: /path/to/file.scap
+  gvisor:
+    config: /path/to/gvisor_config.yaml
+    root: ""
+
+#######################################
+# Falco performance tuning (advanced) #
+#######################################
+
+# The `engine` config is unchanged so these configs are used
+syscall_buf_size_preset: 6
+
+syscall_drop_failed_exit: true
+
+modern_bpf:
+  cpus_for_each_syscall_buffer: 3

unit_tests/falco_test_var.h.in

@@ -1,3 +1,4 @@
 #pragma once
 
-#define ENGINE_SELECTION_TEST_CONFIG "${CMAKE_SOURCE_DIR}/unit_tests/falco/test_configs/test_engine_selection_precedence.yaml"
+#define NEW_ENGINE_CONFIG_CHANGED "${CMAKE_SOURCE_DIR}/unit_tests/falco/test_configs/new_engine_config_changed.yaml"
+#define NEW_ENGINE_CONFIG_UNCHANGED "${CMAKE_SOURCE_DIR}/unit_tests/falco/test_configs/new_engine_config_unchanged.yaml"

userspace/falco/configuration.cpp

@@ -184,7 +184,12 @@ void falco_configuration::load_engine_config(const std::string& config_name, con
 	}
 	
 	// If we arrive here it means we have at least one change in the `engine` config.
+	// Please note that `load_config` is called more than one time during initialization
+	// so the last time wins
 	m_changes_in_engine_config = true;
+	m_syscall_buf_size_preset = 0;
+	m_cpus_for_each_syscall_buffer = 0;
+	m_syscall_drop_failed_exit = false;
 }
 
 void falco_configuration::load_yaml(const std::string& config_name, const yaml_helper& config)

userspace/falco/configuration.h

@@ -172,9 +172,9 @@ public:
 	// used to keep track if the `engine` config is used.
 	bool m_changes_in_engine_config = false;
 	// Index corresponding to the syscall buffer dimension.
-	uint16_t m_syscall_buf_size_preset = 4;
+	uint16_t m_syscall_buf_size_preset = 0;
 	// Number of CPUs associated with a single ring buffer.
-	uint16_t m_cpus_for_each_syscall_buffer = 2;
+	uint16_t m_cpus_for_each_syscall_buffer = 0;
 	bool m_syscall_drop_failed_exit = false;
 
 private: