feat(ffe): wire remote config lifecycle

components-rs/Cargo.toml

@@ -16,7 +16,7 @@ datadog-live-debugger = { path = "../libdatadog/datadog-live-debugger" }
 datadog-live-debugger-ffi = { path = "../libdatadog/datadog-live-debugger-ffi", default-features = false }
 datadog-ipc = { path = "../libdatadog/datadog-ipc" }
 datadog-ffe = { path = "../libdatadog/datadog-ffe" }
-datadog-remote-config = { path = "../libdatadog/datadog-remote-config" }
+datadog-remote-config = { path = "../libdatadog/datadog-remote-config", features = ["ffe"] }
 datadog-sidecar = { path = "../libdatadog/datadog-sidecar" }
 datadog-sidecar-ffi = { path = "../libdatadog/datadog-sidecar-ffi" }
 libdd-data-pipeline = { path = "../libdatadog/libdd-data-pipeline" }

components-rs/common.h

@@ -480,6 +480,19 @@ typedef struct ddog_SidecarTransport ddog_SidecarTransport;
  */
 typedef struct ddog_SpanConcentrator ddog_SpanConcentrator;
 
+/**
+ * Flags selecting which Remote Config products/capabilities to subscribe to.
+ *
+ * Passed as a single C-ABI struct so call sites can use designated initializers
+ * and name the flags, instead of a positional sequence of bool args.
+ */
+typedef struct ddog_DdogRemoteConfigFlags {
+  bool live_debugging_enabled;
+  bool appsec_activation;
+  bool appsec_config;
+  bool ffe_enabled;
+} ddog_DdogRemoteConfigFlags;
+
 /**
  * Holds the raw parts of a Rust Vec; it should only be created from Rust,
  * never from C.

components-rs/ddtrace.h

@@ -144,9 +144,7 @@ void ddog_reset_logger(void);
 
 uint32_t ddog_get_logs_count(ddog_CharSlice level);
 
-void ddog_init_remote_config(bool live_debugging_enabled,
-                             bool appsec_activation,
-                             bool appsec_config);
+void ddog_init_remote_config(struct ddog_DdogRemoteConfigFlags flags);
 
 struct ddog_RemoteConfigState *ddog_init_remote_config_state(const struct ddog_Endpoint *endpoint,
                                                              bool di_enabled);

components-rs/remote_config.rs

@@ -1,4 +1,5 @@
 use crate::sidecar::MaybeShmLimiter;
+use datadog_ffe::rules_based::Configuration;
 use datadog_live_debugger::debugger_defs::{DebuggerData, DebuggerPayload};
 use datadog_live_debugger::{FilterList, LiveDebuggingData, ServiceConfiguration};
 use datadog_live_debugger_ffi::data::Probe;
@@ -116,13 +117,28 @@ pub struct LiveDebuggerState {
     pub di_enabled: bool,
 }
 
+/// Flags selecting which Remote Config products/capabilities to subscribe to.
+///
+/// Passed as a single C-ABI struct so call sites can use designated initializers
+/// and name the flags, instead of a positional sequence of bool args.
+#[repr(C)]
+pub struct DdogRemoteConfigFlags {
+    pub live_debugging_enabled: bool,
+    pub appsec_activation: bool,
+    pub appsec_config: bool,
+    pub ffe_enabled: bool,
+}
+
 #[no_mangle]
 #[allow(static_mut_refs)]
-pub unsafe extern "C" fn ddog_init_remote_config(
-    live_debugging_enabled: bool,
-    appsec_activation: bool,
-    appsec_config: bool,
-) {
+pub unsafe extern "C" fn ddog_init_remote_config(flags: DdogRemoteConfigFlags) {
+    let DdogRemoteConfigFlags {
+        live_debugging_enabled,
+        appsec_activation,
+        appsec_config,
+        ffe_enabled,
+    } = flags;
+
     DDTRACE_REMOTE_CONFIG_PRODUCTS.push(RemoteConfigProduct::ApmTracing);
     DDTRACE_REMOTE_CONFIG_CAPABILITIES.push(RemoteConfigCapabilities::ApmTracingCustomTags);
     DDTRACE_REMOTE_CONFIG_CAPABILITIES.push(RemoteConfigCapabilities::ApmTracingEnabled);
@@ -139,6 +155,11 @@ pub unsafe extern "C" fn ddog_init_remote_config(
         DDTRACE_REMOTE_CONFIG_CAPABILITIES.push(RemoteConfigCapabilities::AsmActivation);
     }
 
+    if ffe_enabled {
+        DDTRACE_REMOTE_CONFIG_PRODUCTS.push(RemoteConfigProduct::FfeFlags);
+        DDTRACE_REMOTE_CONFIG_CAPABILITIES.push(RemoteConfigCapabilities::FfeFlagConfigurationRules);
+    }
+
     if live_debugging_enabled {
         DDTRACE_REMOTE_CONFIG_PRODUCTS.push(RemoteConfigProduct::LiveDebugger)
     }
@@ -377,6 +398,10 @@ pub extern "C" fn ddog_process_remote_configs(remote_config: &mut RemoteConfigSt
                         );
                     }
                 }
+                RemoteConfigData::FfeFlags(ufc) => {
+                    debug!("Received FFE flags configuration");
+                    crate::ffe::store_config(Configuration::from_server_response(ufc));
+                }
                 RemoteConfigData::Ignored(_) => (),
                 RemoteConfigData::TracerFlareConfig(_) => {}
                 RemoteConfigData::TracerFlareTask(_) => {}
@@ -402,6 +427,10 @@ pub extern "C" fn ddog_process_remote_configs(remote_config: &mut RemoteConfigSt
                         }
                     }
                 }
+                RemoteConfigProduct::FfeFlags => {
+                    debug!("FFE flags configuration removed");
+                    crate::ffe::clear_config();
+                }
                 _ => (),
             },
         }

ext/configuration.h

@@ -278,6 +278,7 @@ enum ddtrace_sidecar_connection_mode {
     CONFIG(INT, DD_CODE_ORIGIN_MAX_USER_FRAMES, "8")                                                           \
     CONFIG(BOOL, DD_TRACE_RESOURCE_RENAMING_ENABLED, "false")                                                  \
     CONFIG(BOOL, DD_TRACE_RESOURCE_RENAMING_ALWAYS_SIMPLIFIED_ENDPOINT, "false")                               \
+    CONFIG(BOOL, DD_EXPERIMENTAL_FLAGGING_PROVIDER_ENABLED, "false")                                           \
     CONFIG(BOOL, DD_EXPERIMENTAL_PROPAGATE_PROCESS_TAGS_ENABLED, "true")                                       \
     CONFIG(BOOL, DD_TRACE_STATS_COMPUTATION_ENABLED, "false")                                                  \
     DD_INTEGRATIONS

ext/sidecar.c

@@ -390,7 +390,12 @@ void ddtrace_sidecar_setup(bool appsec_activation, bool appsec_config) {
     ddtrace_set_non_resettable_sidecar_globals();
     ddtrace_set_resettable_sidecar_globals();
 
-    ddog_init_remote_config(get_global_DD_INSTRUMENTATION_TELEMETRY_ENABLED(), appsec_activation, appsec_config);
+    ddog_init_remote_config((struct ddog_DdogRemoteConfigFlags){
+        .live_debugging_enabled = get_global_DD_INSTRUMENTATION_TELEMETRY_ENABLED(),
+        .appsec_activation = appsec_activation,
+        .appsec_config = appsec_config,
+        .ffe_enabled = get_global_DD_EXPERIMENTAL_FLAGGING_PROVIDER_ENABLED(),
+    });
 
     zend_long mode = get_global_DD_TRACE_SIDECAR_CONNECTION_MODE();
 

metadata/supported-configurations.json

@@ -382,6 +382,13 @@
         "default": "false"
       }
     ],
+    "DD_EXPERIMENTAL_FLAGGING_PROVIDER_ENABLED": [
+      {
+        "implementation": "A",
+        "type": "boolean",
+        "default": "false"
+      }
+    ],
     "DD_EXPERIMENTAL_PROPAGATE_PROCESS_TAGS_ENABLED": [
       {
         "implementation": "B",

tests/ext/ffe/remote_config_lifecycle.phpt

@@ -0,0 +1,90 @@
+--TEST--
+FFE Remote Config loads and removes UFC config
+--SKIPIF--
+<?php include __DIR__ . '/../includes/skipif_no_dev_env.inc'; ?>
+--ENV--
+DD_AGENT_HOST=request-replayer
+DD_TRACE_AGENT_PORT=80
+DD_TRACE_GENERATE_ROOT_SPAN=0
+DD_REMOTE_CONFIG_POLL_INTERVAL_SECONDS=0.01
+DD_EXPERIMENTAL_FLAGGING_PROVIDER_ENABLED=1
+--INI--
+datadog.trace.agent_test_session_token=ffe/remote_config_lifecycle
+--FILE--
+<?php
+require __DIR__ . "/../remote_config/remote_config.inc";
+include __DIR__ . '/../includes/request_replayer.inc';
+
+function show($label, $value) {
+    echo $label . '=' . json_encode($value, JSON_UNESCAPED_SLASHES) . "\n";
+}
+
+function put_ffe_config_file($json) {
+    $path = "datadog/2/FFE_FLAGS/" . sha1($json) . "/config";
+    put_rc_file($path, $json);
+    return $path;
+}
+
+function wait_for_ffe_config($expected) {
+    for ($i = 0; $i < 200; $i++) {
+        if (\DDTrace\ffe_has_config() === $expected) {
+            return true;
+        }
+        usleep(100000);
+    }
+    return false;
+}
+
+reset_request_replayer();
+show('before', \DDTrace\ffe_has_config());
+
+$config = <<<'JSON'
+{
+  "createdAt": "2024-01-01T00:00:00Z",
+  "environment": {"name": "test"},
+  "flags": {
+    "string.flag": {
+      "key": "string.flag",
+      "enabled": true,
+      "variationType": "STRING",
+      "variations": {
+        "blue": {"key": "blue", "value": "blue"}
+      },
+      "allocations": [{
+        "key": "alloc-string",
+        "rules": [],
+        "splits": [{"variationKey": "blue", "serialId": 7, "shards": []}],
+        "doLog": true
+      }]
+    }
+  }
+}
+JSON;
+
+$path = put_ffe_config_file($config);
+\DDTrace\start_span();
+
+show('loaded', wait_for_ffe_config(true));
+show('has_config_after_add', \DDTrace\ffe_has_config());
+show('success', \DDTrace\ffe_evaluate('string.flag', 0, 'user-1', array()));
+
+$version = \DDTrace\ffe_config_version();
+del_rc_file($path);
+
+show('removed', wait_for_ffe_config(false));
+show('has_config_after_remove', \DDTrace\ffe_has_config());
+show('version_increased', \DDTrace\ffe_config_version() > $version);
+?>
+--CLEAN--
+<?php
+require __DIR__ . "/../remote_config/remote_config.inc";
+reset_request_replayer();
+?>
+--EXPECT--
+before=false
+loaded=true
+has_config_after_add=true
+success={"value_json":"\"blue\"","variant":"blue","allocation_key":"alloc-string","reason":0,"error_code":0,"do_log":true}
+removed=true
+has_config_after_remove=false
+version_increased=true