Collect agent info and apply the env for remote config

Signed-off-by: Bob Weinand <bob.weinand@datadoghq.com>

components-rs/common.h

@@ -821,6 +821,8 @@ typedef struct ddog_ContextKey {
   enum ddog_MetricType _1;
 } ddog_ContextKey;
 
+typedef struct ddog_AgentInfoReader ddog_AgentInfoReader;
+
 typedef struct ddog_AgentRemoteConfigReader ddog_AgentRemoteConfigReader;
 
 typedef struct ddog_AgentRemoteConfigWriter_ShmHandle ddog_AgentRemoteConfigWriter_ShmHandle;

components-rs/sidecar.h

@@ -306,4 +306,19 @@ void ddog_sidecar_reconnect(struct ddog_SidecarTransport **transport,
  */
 ddog_CharSlice ddog_sidecar_get_crashtracker_unix_socket_path(void);
 
+/**
+ * Gets an agent info reader.
+ */
+struct ddog_AgentInfoReader *ddog_get_agent_info_reader(const struct ddog_Endpoint *endpoint);
+
+/**
+ * Gets the current agent info environment (or empty if not existing)
+ */
+ddog_CharSlice ddog_get_agent_info_env(struct ddog_AgentInfoReader *reader, bool *changed);
+
+/**
+ * Drops the agent info reader.
+ */
+void ddog_drop_agent_info_reader(struct ddog_AgentInfoReader*);
+
 #endif /* DDOG_SIDECAR_H */

config.m4

@@ -164,6 +164,7 @@ if test "$PHP_DDTRACE" != "no"; then
   dnl ddtrace.c comes first, then everything else alphabetically
   DD_TRACE_PHP_SOURCES="$EXTRA_PHP_SOURCES \
     ext/ddtrace.c \
+    ext/agent_info.c \
     ext/arrays.c \
     ext/auto_flush.c \
     ext/autoload_php_files.c \

config.w32

@@ -15,7 +15,8 @@ if (PHP_DDTRACE != 'no') {
 
 	var version = PHP_VERSION * 100 + PHP_MINOR_VERSION;
 
-	var DDTRACE_EXT_SOURCES = "arrays.c";
+	var DDTRACE_EXT_SOURCES = "agent_info.c";
+	DDTRACE_EXT_SOURCES += " arrays.c";
 	DDTRACE_EXT_SOURCES += " auto_flush.c";
 	DDTRACE_EXT_SOURCES += " autoload_php_files.c";
 	DDTRACE_EXT_SOURCES += " collect_backtrace.c";

dockerfiles/services/request-replayer/src/index.php

@@ -78,6 +78,7 @@ function decodeDogStatsDMetrics($metrics)
 define('REQUEST_RC_CONFIGS_FILE', getenv('REQUEST_RC_CONFIGS_FILE') ?: ("$temp_location/rc_configs.json"));
 define('REQUEST_METRICS_FILE', getenv('REQUEST_METRICS_FILE') ?: ("$temp_location/metrics.json"));
 define('REQUEST_METRICS_LOG_FILE', getenv('REQUEST_METRICS_LOG_FILE') ?: ("$temp_location/metrics-log.txt"));
+define('REQUEST_AGENT_INFO_FILE', getenv('REQUEST_AGENT_INFO_FILE') ?: ("$temp_location/agent-info.txt"));
 
 function logRequest($message, $data = '')
 {
@@ -91,8 +92,8 @@ function logRequest($message, $data = '')
 }
 
 set_error_handler(function ($number, $message, $errfile, $errline) {
-    if (error_reporting() == 0) {
-        return;
+    if (!($number & error_reporting())) {
+        return true;
     }
     logRequest("Triggered error $number $message in $errfile on line $errline: " . (new \Exception)->getTraceAsString());
     trigger_error($message, $number);
@@ -142,6 +143,9 @@ function logRequest($message, $data = '')
         if (file_exists(REQUEST_NEXT_RESPONSE_FILE)) {
             unlink(REQUEST_NEXT_RESPONSE_FILE);
         }
+        if (file_exists(REQUEST_AGENT_INFO_FILE)) {
+            unlink(REQUEST_AGENT_INFO_FILE);
+        }
         logRequest('Deleted request log');
         break;
     case '/next-response':
@@ -214,6 +218,16 @@ function logRequest($message, $data = '')
             file_put_contents(REQUEST_METRICS_FILE, json_encode($allMetrics));
         }
         break;
+    case '/set-agent-info':
+        $raw = file_get_contents('php://input');
+        file_put_contents(REQUEST_AGENT_INFO_FILE, $raw);
+        break;
+    case '/info':
+        $file = @file_get_contents(REQUEST_AGENT_INFO_FILE) ?: "{}";
+        logRequest('Requested /info endpoint, returning ' . $file);
+        header("datadog-agent-state: " . sha1($file));
+        echo $file;
+        break;
     default:
         $headers = getallheaders();
         if (isset($headers['X-Datadog-Diagnostic-Check']) || isset($headers['x-datadog-diagnostic-check'])) {

ext/agent_info.c

@@ -0,0 +1,22 @@
+#include "agent_info.h"
+#include "ddtrace.h"
+#include "sidecar.h"
+#include "configuration.h"
+
+ZEND_EXTERN_MODULE_GLOBALS(ddtrace);
+
+void ddtrace_check_agent_info_env() {
+    if (DDTRACE_G(agent_info_reader) && ZSTR_LEN(get_DD_ENV()) == 0) {
+        bool changed;
+        ddog_CharSlice env = ddog_get_agent_info_env(DDTRACE_G(agent_info_reader), &changed);
+        if (env.len) {
+            zend_alter_ini_entry_chars(zai_config_memoized_entries[DDTRACE_CONFIG_DD_ENV].ini_entries[0]->name, env.ptr, env.len, ZEND_INI_USER, ZEND_INI_STAGE_RUNTIME);
+        }
+    }
+}
+
+void ddtrace_agent_info_rinit() {
+    if (ddtrace_endpoint && !ZSTR_LEN(get_global_DD_ENV())) {
+        DDTRACE_G(agent_info_reader) = ddog_get_agent_info_reader(ddtrace_endpoint);
+    }
+}

ext/agent_info.h

@@ -0,0 +1,7 @@
+#ifndef DD_AGENT_INFO_H
+#define DD_AGENT_INFO_H
+
+void ddtrace_check_agent_info_env(void);
+void ddtrace_agent_info_rinit(void);
+
+#endif // DD_AGENT_INFO_H

ext/ddtrace.c

@@ -99,6 +99,7 @@
 #include "ddtrace_arginfo.h"
 #include "distributed_tracing_headers.h"
 #include "live_debugger.h"
+#include "agent_info.h"
 
 #if PHP_VERSION_ID < 70200
 #pragma pop_macro("ZVAL_EMPTY_STRING")
@@ -655,6 +656,9 @@ static PHP_GSHUTDOWN_FUNCTION(ddtrace) {
     if (ddtrace_globals->remote_config_state) {
         ddog_shutdown_remote_config(ddtrace_globals->remote_config_state);
     }
+    if (ddtrace_globals->agent_info_reader) {
+        ddog_drop_agent_info_reader(ddtrace_globals->agent_info_reader);
+    }
     zai_hook_gshutdown();
     if (ddtrace_globals->telemetry_buffer) {
         ddog_sidecar_telemetry_buffer_drop(ddtrace_globals->telemetry_buffer);
@@ -1497,7 +1501,6 @@ static void dd_rinit_once(void) {
 static pthread_once_t dd_rinit_once_control = PTHREAD_ONCE_INIT;
 
 static void dd_initialize_request(void) {
-    DDTRACE_G(request_initialized) = true;
     DDTRACE_G(distributed_trace_id) = (ddtrace_trace_id){0};
     DDTRACE_G(distributed_parent_trace_id) = 0;
     DDTRACE_G(additional_global_tags) = zend_new_array(0);
@@ -1507,6 +1510,12 @@ static void dd_initialize_request(void) {
     zend_hash_init(&DDTRACE_G(propagated_root_span_tags), 8, unused, ZVAL_PTR_DTOR, 0);
     zend_hash_init(&DDTRACE_G(tracestate_unknown_dd_keys), 8, unused, ZVAL_PTR_DTOR, 0);
 
+    // Check for the env first, before the first RC
+    ddtrace_check_agent_info_env();
+
+    // Do after env check, so that RC data is not updated before RC init
+    DDTRACE_G(request_initialized) = true;
+
     ddtrace_sidecar_rinit();
 
     // Things that should only run on the first RINIT after each minit.
@@ -1546,6 +1555,8 @@ static void dd_initialize_request(void) {
     }
 #endif
 
+    ddtrace_agent_info_rinit();
+
     // Reset compile time after request init hook has compiled
     ddtrace_compile_time_reset();
 
@@ -2240,6 +2251,10 @@ void dd_internal_handle_fork(void) {
         ddog_shutdown_remote_config(DDTRACE_G(remote_config_state));
         DDTRACE_G(remote_config_state) = NULL;
     }
+    if (DDTRACE_G(agent_info_reader)) {
+        ddog_drop_agent_info_reader(DDTRACE_G(agent_info_reader));
+        DDTRACE_G(agent_info_reader) = NULL;
+    }
     ddtrace_seed_prng();
     ddtrace_generate_runtime_id();
     ddtrace_reset_sidecar_globals();

ext/ddtrace.h

@@ -133,6 +133,7 @@ ZEND_BEGIN_MODULE_GLOBALS(ddtrace)
     ddog_QueueId sidecar_queue_id;
     ddog_AgentRemoteConfigReader *agent_config_reader;
     ddog_RemoteConfigState *remote_config_state;
+    ddog_AgentInfoReader *agent_info_reader;
     zend_arena *debugger_capture_arena;
     ddog_Vec_DebuggerPayload exception_debugger_buffer;
     HashTable active_rc_hooks;

ext/priority_sampling/priority_sampling.c

@@ -13,6 +13,7 @@
 #include "ddtrace.h"
 #include "span.h"
 #include "components/log/log.h"
+#include "agent_info.h"
 
 ZEND_EXTERN_MODULE_GLOBALS(ddtrace);
 
@@ -217,6 +218,9 @@ static void dd_decide_on_sampling(ddtrace_root_span_data *span) {
     bool explicit_rule = true;
 
     if (is_trace_root) {
+        // when we sample, we need to fetch the env first
+        ddtrace_check_agent_info_env();
+
         double default_sample_rate = get_DD_TRACE_SAMPLE_RATE();
         sample_rate = default_sample_rate >= 0 ? default_sample_rate : 1;
 
@@ -227,16 +231,22 @@ static void dd_decide_on_sampling(ddtrace_root_span_data *span) {
         } else {
             explicit_rule = false;
 
+            zval *env = zend_hash_str_find(ddtrace_property_array(&span->property_meta), ZEND_STRL("env"));
+            if (!env) {
+                env = &span->property_env;
+            }
+
             ddtrace_try_read_agent_rate();
+            // if we have an empty env... we can default to the cluster env.
+            if (ZSTR_LEN(get_DD_ENV()) && Z_TYPE_P(env) == IS_STRING && Z_STRLEN_P(env) == 0) {
+                zval_ptr_dtor(env);
+                ZVAL_STR_COPY(env, get_DD_ENV());
+            }
 
             if (DDTRACE_G(agent_rate_by_service)) {
-                zval *env = zend_hash_str_find(ddtrace_property_array(&span->property_meta), ZEND_STRL("env"));
-                if (!env) {
-                    env = &span->property_env;
-                }
                 zval *sample_rate_zv = NULL;
                 zval *service = &span->property_service;
-                if (Z_TYPE_P(service) == IS_STRING && env && Z_TYPE_P(env) == IS_STRING) {
+                if (Z_TYPE_P(service) == IS_STRING && Z_TYPE_P(env) == IS_STRING) {
                     zend_string *sample_key = zend_strpprintf(0, "service:%.*s,env:%.*s", (int) Z_STRLEN_P(service), Z_STRVAL_P(service),
                                                               (int) Z_STRLEN_P(env), Z_STRVAL_P(env));
                     sample_rate_zv = zend_hash_find(DDTRACE_G(agent_rate_by_service), sample_key);

ext/serializer.c

@@ -44,6 +44,7 @@
 #include "sidecar.h"
 #include "live_debugger.h"
 #include "exception_serialize.h"
+#include "agent_info.h"
 
 ZEND_EXTERN_MODULE_GLOBALS(ddtrace);
 

tests/ext/request-replayer/dd_trace_agent_env.phpt

@@ -0,0 +1,37 @@
+--TEST--
+DDTrace\ExceptionSpanEvent serialization with overridden attributes
+--SKIPIF--
+<?php include __DIR__ . '/../includes/skipif_no_dev_env.inc'; ?>
+<?php
+echo "nocache\n";
+$ctx = stream_context_create([
+    'http' => [
+        'method' => 'PUT',
+        "header" => [
+            "Content-Type: application/json",
+            "X-Datadog-Test-Session-Token: dd_trace_agent_env",
+        ],
+        'content' => '{"config":{"default_env":"test_env"}}'
+    ]
+]);
+file_get_contents("http://request-replayer/set-agent-info", false, $ctx);
+?>
+--ENV--
+DD_AGENT_HOST=request-replayer
+DD_TRACE_AGENT_PORT=80
+DD_TRACE_AGENT_FLUSH_INTERVAL=333
+DD_TRACE_GENERATE_ROOT_SPAN=0
+--INI--
+datadog.env=
+datadog.trace.agent_test_session_token=dd_trace_agent_env
+--FILE--
+<?php
+
+$span = \DDTrace\start_span();
+usleep(500000);
+\DDTrace\close_span();
+var_dump($span->env);
+
+?>
+--EXPECTF--
+string(8) "test_env"