cleanup: rename none into nodriver

Signed-off-by: Andrea Terzolo <[email protected]>
Co-authored-by: Luca Guerra <[email protected]>

falco.yaml

@@ -179,7 +179,8 @@ rules_file:
 # - `modern_ebpf`: Modern eBPF (CO-RE eBPF probe)
 # - `gvisor`: gVisor (gVisor sandbox)
 # - `replay`: Replay a scap trace file
-# - `none`: No event producer loaded, useful to run with plugins.
+# - `nodriver`: No driver is injected into the system.
+#   This is useful to debug and to run plugins with 'syscall' source.
 #
 # Only one engine can be specified in the `kind` key.
 # Moreover, for each engine multiple options might be available,

userspace/falco/app/actions/load_config.cpp

@@ -125,8 +125,8 @@ static falco::app::run_result apply_deprecated_options(falco::app::state& s)
 	}
 	if (s.options.nodriver)
 	{
-		falco_logger::log(falco_logger::level::WARNING, "DEPRECATION NOTICE: the '--nodriver' command line option is deprecated and will be removed in Falco 0.38! Set 'engine.kind: none' instead in falco.yaml\n");
-		s.config->m_engine_mode =  engine_kind_t::NONE;
+		falco_logger::log(falco_logger::level::WARNING, "DEPRECATION NOTICE: the '--nodriver' command line option is deprecated and will be removed in Falco 0.38! Set 'engine.kind: nodriver' instead in falco.yaml\n");
+		s.config->m_engine_mode =  engine_kind_t::NODRIVER;
 	}
 	if (!s.options.capture_file.empty())
 	{

userspace/falco/app/state.h

@@ -168,7 +168,7 @@ struct state
 
     inline bool is_nodriver() const
     {
-        return config->m_engine_mode == engine_kind_t::NONE;
+        return config->m_engine_mode == engine_kind_t::NODRIVER;
     }
 
     inline bool is_source_enabled(const std::string& src) const

userspace/falco/configuration.cpp

@@ -109,7 +109,7 @@ void falco_configuration::load_engine_config(const std::string& config_name, con
 		{"modern_ebpf",engine_kind_t::MODERN_EBPF},
 		{"replay",engine_kind_t::REPLAY},
 		{"gvisor",engine_kind_t::GVISOR},
-		{"none",engine_kind_t::NONE},
+		{"nodriver",engine_kind_t::NODRIVER},
 	};
 
 	auto driver_mode_str = config.get_scalar<std::string>("engine.kind", "kmod");
@@ -172,7 +172,7 @@ void falco_configuration::load_engine_config(const std::string& config_name, con
 		}
 		m_gvisor.m_root = config.get_scalar<std::string>("engine.gvisor.root", "");
 		break;
-	case engine_kind_t::NONE:
+	case engine_kind_t::NODRIVER:
 	default:
 		break;
 	}

userspace/falco/configuration.h

@@ -49,7 +49,7 @@ enum class engine_kind_t : uint8_t
 	MODERN_EBPF,
 	REPLAY,
 	GVISOR,
-	NONE
+	NODRIVER
 };
 
 class falco_configuration