feat: publish Linux OTel contexts

.gitlab/build-sidecar.sh

@@ -21,4 +21,5 @@ fi
 
 SHARED=1 PROFILE=tracer-release host_os="${HOST_OS}" ./compile_rust.sh
 cp -v "${CARGO_TARGET_DIR:-target}/tracer-release/libdatadog_php.a" "libdatadog_php_$(uname -m)${suffix}.a"
-objcopy --compress-debug-sections "${CARGO_TARGET_DIR:-target}/tracer-release/libdatadog_php.so" "libdatadog_php_$(uname -m)${suffix}.so"
+output="libdatadog_php_$(uname -m)${suffix}.so"
+objcopy --compress-debug-sections "${CARGO_TARGET_DIR:-target}/tracer-release/libdatadog_php.so" "${output}"

.gitlab/compile_extension.sh

@@ -25,5 +25,10 @@ make -j static &
 wait
 
 # Link extension
-sed -i 's/-export-symbols .*\/datadog\.sym/-Wl,--retain-symbols-file=datadog.sym/g' ${EXTENSION_DIR}/ddtrace.ldflags
+if [ "$(uname -s)" = "Linux" ]; then
+  export_symbols_file="datadog-linux.sym"
+else
+  export_symbols_file="datadog.sym"
+fi
+sed -i -E "s#-export-symbols [^ ]+#-Wl,--retain-symbols-file=${export_symbols_file}#g" "${EXTENSION_DIR}/ddtrace.ldflags"
 cc -shared -Wl,-whole-archive ${MODULES_DIR}/ddtrace.a -Wl,-no-whole-archive $(cat ${EXTENSION_DIR}/ddtrace.ldflags) ${CARGO_TARGET_DIR}/debug/libdatadog_php.a -Wl,-soname -Wl,ddtrace.so -o ${MODULES_DIR}/ddtrace.so

.gitlab/link-tracing-extension.sh

@@ -3,7 +3,11 @@ set -e -o pipefail
 
 suffix="${1:-}"
 
-sed -i 's/-export-symbols .*\/datadog\.sym/-Wl,--retain-symbols-file=datadog.sym/g' "ddtrace_$(uname -m)${suffix}.ldflags"
+export_symbols_file="datadog.sym"
+if [ "$(uname -s)" = "Linux" ]; then
+  export_symbols_file="datadog-linux.sym"
+fi
+sed -i -E "s#-export-symbols [^ ]+#-Wl,--retain-symbols-file=${export_symbols_file}#g" "ddtrace_$(uname -m)${suffix}.ldflags"
 pids=()
 for archive in extensions_$(uname -m)/*.a; do
   (

Cargo.toml

@@ -42,22 +42,21 @@ inherits = "release"
 # level, so they are mirrored here too.
 [workspace.dependencies]
 anyhow = { version = "1.0", default-features = false }
-arc-swap = "1.7.1"
-hyper = { version = "1.6", features = [
-  "http1",
-  "client",
-], default-features = false }
-hyper-util = { version = "0.1.10", features = [
-  "http1",
-  "client",
-  "client-legacy",
-] }
+arc-swap = { version = "1.7.1", default-features = false }
+futures = { version = "0.3", default-features = false }
+hyper = { version = "1.6", default-features = false }
+hyper-util = { version = "0.1.10", default-features = false }
+io-lifetimes = { version = "1.0", default-features = false }
+libc = { version = "0.2", default-features = true }
 prost-build = { version = "0.14.1", default-features = false }
 protoc-bin-vendored = { version = "3.0.0", default-features = false }
+rustls = { version = "0.23", default-features = false }
 serde = { version = "1.0", default-features = false }
 serde_json = { version = "1.0", default-features = false, features = ["alloc"] }
+syn = { version = "^2", default-features = false }
 tokio = { version = "1.36", default-features = false }
 tracing = { version = "0.1", default-features = false }
+uuid = { version = "1.7.0", default-features = false }
 
 [workspace.lints]
 # empty for compat with libdatadog

Makefile

@@ -48,7 +48,7 @@ RUN_TESTS_CMD := DD_SERVICE= DD_ENV= REPORT_EXIT_STATUS=1 TEST_PHP_SRCDIR=$(PROJ
 
 C_FILES = $(shell find components components-rs ext src/dogstatsd tracer zend_abstract_interface -name '*.c' -o -name '*.h' | awk '{ printf "$(BUILD_DIR)/%s\n", $$1 }' )
 TEST_FILES = $(shell find tests/ext -name '*.php*' -o -name '*.inc' -o -name '*.json' -o -name '*.yaml' -o -name 'CONFLICTS' | awk '{ printf "$(BUILD_DIR)/%s\n", $$1 }' )
-RUST_FILES = $(BUILD_DIR)/Cargo.toml $(BUILD_DIR)/Cargo.lock $(shell find components-rs -name '*.c' -o -name '*.rs' -o -name 'Cargo.toml' | awk '{ printf "$(BUILD_DIR)/%s\n", $$1 }' ) $(shell find libdatadog/{build-common,datadog-ffe,datadog-ipc,datadog-ipc-macros,datadog-live-debugger,datadog-live-debugger-ffi,libdd-remote-config,datadog-sidecar,datadog-sidecar-ffi,datadog-sidecar-macros,libdd-alloc,libdd-capabilities,libdd-capabilities-impl,libdd-common,libdd-common-ffi,libdd-crashtracker,libdd-crashtracker-ffi,libdd-data-pipeline,libdd-ddsketch,libdd-dogstatsd-client,libdd-library-config,libdd-library-config-ffi,libdd-log,libdd-shared-runtime,libdd-telemetry,libdd-telemetry-ffi,libdd-tinybytes,libdd-trace-*,spawn_worker,tools/{cc_utils,sidecar_mockgen},libdd-trace-*,Cargo.toml} \( -type l -o -type f \) \( -path "*/src*" -o -path "*/examples*" -o -path "*Cargo.toml" -o -path "*/build.rs" -o -path "*/tests/dataservice.rs" -o -path "*/tests/service_functional.rs" \) -not -path "*/datadog-ipc/build.rs" -not -path "*/datadog-sidecar-ffi/build.rs")
+RUST_FILES = $(BUILD_DIR)/Cargo.toml $(BUILD_DIR)/Cargo.lock $(shell find components-rs -name '*.c' -o -name '*.rs' -o -name 'Cargo.toml' | awk '{ printf "$(BUILD_DIR)/%s\n", $$1 }' ) $(shell find libdatadog/{build-common,datadog-ffe,datadog-ipc,datadog-ipc-macros,datadog-live-debugger,datadog-live-debugger-ffi,libdd-remote-config,datadog-sidecar,datadog-sidecar-ffi,datadog-sidecar-macros,libdd-alloc,libdd-capabilities,libdd-capabilities-impl,libdd-common,libdd-common-ffi,libdd-crashtracker,libdd-crashtracker-ffi,libdd-data-pipeline,libdd-ddsketch,libdd-dogstatsd-client,libdd-library-config,libdd-library-config-ffi,libdd-log,libdd-otel-thread-ctx,libdd-shared-runtime,libdd-telemetry,libdd-telemetry-ffi,libdd-tinybytes,libdd-trace-*,spawn_worker,tools/{cc_utils,sidecar_mockgen},libdd-trace-*,Cargo.toml} \( -type l -o -type f \) \( -path "*/src*" -o -path "*/examples*" -o -path "*Cargo.toml" -o -path "*/build.rs" -o -path "*/tests/dataservice.rs" -o -path "*/tests/service_functional.rs" \) -not -path "*/datadog-ipc/build.rs" -not -path "*/datadog-sidecar-ffi/build.rs")
 ALL_OBJECT_FILES = $(C_FILES) $(RUST_FILES) $(BUILD_DIR)/Makefile
 TEST_OPCACHE_FILES = $(shell find tests/opcache -name '*.php*' -o -name '.gitkeep' | awk '{ printf "$(BUILD_DIR)/%s\n", $$1 }' )
 TEST_STUB_FILES = $(shell find tests/ext -type d -name 'stubs' -exec find '{}' -type f \; | awk '{ printf "$(BUILD_DIR)/%s\n", $$1 }' )
@@ -106,7 +106,7 @@ JUNIT_RESULTS_DIR := $(shell pwd)
 
 all: $(BUILD_DIR)/configure $(SO_FILE)
 
-$(BUILD_DIR)/configure: $(M4_FILES) $(BUILD_DIR)/datadog.sym $(BUILD_DIR)/VERSION
+$(BUILD_DIR)/configure: $(M4_FILES) $(BUILD_DIR)/datadog.sym $(BUILD_DIR)/datadog-linux.sym $(BUILD_DIR)/VERSION
 	$(Q) (cd $(BUILD_DIR); phpize && $(SED_I) 's/\/FAILED/\/\\bFAILED/' $(BUILD_DIR)/run-tests.php) # Fix PHP 5.4 exit code bug when running selected tests (FAILED vs XFAILED)
 
 $(BUILD_DIR)/run-tests.php: $(if $(ASSUME_COMPILED),, $(BUILD_DIR)/configure)

appsec/cmake/ddtrace.cmake

@@ -26,9 +26,9 @@ add_custom_target(libdatadog_stamp
 if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
 set(EXPORTS_FILE "${CMAKE_BINARY_DIR}/ddtrace_exports.version")
 add_custom_target(ddtrace_exports
-    COMMAND bash -c "{ echo -e '{\\nglobal:'; sed 's/$/;/' '${CMAKE_SOURCE_DIR}'/../datadog.sym; echo -e 'local:\\n*;\\n};'; } > '${EXPORTS_FILE}'"
+    COMMAND bash -c "{ echo -e '{\\nglobal:'; sed 's/$/;/' '${CMAKE_SOURCE_DIR}'/../datadog-linux.sym; echo -e 'local:\\n*;\\n};'; } > '${EXPORTS_FILE}'"
     BYPRODUCTS ${EXPORTS_FILE}
-    DEPENDS ${CMAKE_SOURCE_DIR}/../datadog.sym
+    DEPENDS ${CMAKE_SOURCE_DIR}/../datadog-linux.sym
     VERBATIM
 )
 elseif(APPLE)

components-rs/Cargo.toml

@@ -56,6 +56,9 @@ libc = "0.2"
 bincode = { version = "1.3.3" }
 hashbrown = "0.15"
 
+[target.'cfg(target_os = "linux")'.dependencies]
+libdd-library-config = { path = "../libdatadog/libdd-library-config", default-features = false, features = ["otel-thread-ctx"] }
+
 [build-dependencies]
 cbindgen = "0.27"
 

components-rs/build.rs

@@ -1,6 +1,6 @@
 fn main() {
     // On Linux, set ddog_spawn_direct_entry as the ELF entry point for the
-    // cdylib build (libdatadog_php.so in SSI deployments).  This allows ld.so
+    // cdylib build (libdatadog_php.so in SSI deployments). This allows ld.so
     // to exec the library directly without a trampoline binary.
     if std::env::var("CARGO_CFG_TARGET_OS").as_deref() == Ok("linux") {
         println!("cargo:rustc-cdylib-link-arg=-Wl,-e,ddog_spawn_direct_entry");

components-rs/datadog.h

@@ -41,6 +41,11 @@ void datadog_generate_session_id(void);
 
 void datadog_format_runtime_id(uint8_t (*buf)[36]);
 
+#ifdef __linux__
+bool datadog_publish_otel_process_context(ddog_CharSlice process_tags);
+
+#endif
+
 ddog_CharSlice ddtrace_get_container_id(void);
 
 void ddtrace_set_container_cgroup_path(ddog_CharSlice path);

components-rs/lib.rs

@@ -90,6 +90,72 @@ pub extern "C" fn datadog_format_runtime_id(buf: &mut [u8; 36]) {
     unsafe { datadog_runtime_id.as_hyphenated().encode_lower(buf) };
 }
 
+#[cfg(target_os = "linux")]
+fn char_slice_string(value: CharSlice<'_>) -> String {
+    value.to_utf8_lossy().into_owned()
+}
+
+#[cfg(target_os = "linux")]
+fn hostname() -> String {
+    let max_len = unsafe { libc::sysconf(libc::_SC_HOST_NAME_MAX) };
+    let max_len = usize::try_from(max_len).unwrap_or(255);
+    let mut buffer = vec![0; max_len.saturating_add(1)];
+
+    if unsafe { libc::gethostname(buffer.as_mut_ptr().cast(), buffer.len()) } != 0 {
+        return String::new();
+    }
+
+    let len = buffer
+        .iter()
+        .position(|&byte| byte == 0)
+        .unwrap_or(buffer.len());
+    String::from_utf8_lossy(&buffer[..len]).into_owned()
+}
+
+/// Publish or update dd-trace-php's standard Linux OTel Process Context.
+#[cfg(target_os = "linux")]
+#[no_mangle]
+pub extern "C" fn datadog_publish_otel_process_context(process_tags: CharSlice<'_>) -> bool {
+    use libdd_library_config::otel_process_ctx;
+    use libdd_library_config::tracer_metadata::{ThreadLocalMetadata, TracerMetadata};
+
+    let metadata = TracerMetadata {
+        // Safety: the runtime ID is only mutated from single-threaded contexts.
+        runtime_id: Some(unsafe { datadog_runtime_id.as_hyphenated().to_string() }),
+        tracer_language: "php".to_owned(),
+        tracer_version: include_str!("../VERSION").trim().to_owned(),
+        hostname: hostname(),
+        process_tags: Some(char_slice_string(process_tags)),
+        container_id: get_container_id().map(str::to_owned),
+        threadlocal_metadata: Some(ThreadLocalMetadata {
+            attribute_keys: vec![
+                "service.name".to_owned(),
+                "deployment.environment.name".to_owned(),
+                "service.version".to_owned(),
+                "thread.id".to_owned(),
+            ],
+            ..Default::default()
+        }),
+        ..Default::default()
+    };
+
+    let mut context = metadata.to_otel_process_ctx();
+    // TracerMetadata emits empty resource attributes for absent optional fields to advertise
+    // support. These values can vary independently on every PHP request, so their values and
+    // resource keys must be omitted from the process-wide context. The keys remain discoverable
+    // through threadlocal.attribute_key_map.
+    if let Some(resource) = context.resource.as_mut() {
+        resource.attributes.retain(|attribute| {
+            !matches!(
+                attribute.key.as_str(),
+                "service.name" | "service.version" | "deployment.environment.name"
+            )
+        });
+    }
+
+    otel_process_ctx::publish(&context).is_ok()
+}
+
 #[must_use]
 #[no_mangle]
 pub extern "C" fn ddtrace_get_container_id() -> CharSlice<'static> {

config.m4

@@ -100,6 +100,19 @@ if test "$PHP_DDTRACE" != "no"; then
       EXTRA_CFLAGS="$EXTRA_CFLAGS -Wno-microsoft-anon-tag"
     ])
 
+  case "$host_os:$host_cpu" in
+    linux*:x86_64)
+      AC_LIBTOOL_COMPILER_OPTION([whether -mtls-dialect=gnu2 is a valid compiler argument],
+        lt_cv_ddtrace_tls_dialect_gnu2,
+        [-mtls-dialect=gnu2], [],
+        [
+          CFLAGS="$CFLAGS -mtls-dialect=gnu2"
+          EXTRA_CFLAGS="$EXTRA_CFLAGS -mtls-dialect=gnu2"
+        ],
+        [AC_MSG_ERROR([x86-64 Linux OTel context sharing requires compiler support for -mtls-dialect=gnu2])])
+      ;;
+  esac
+
   DD_TRACE_VENDOR_SOURCES="\
     tracer/vendor/mpack/mpack.c \
     tracer/vendor/mt19937/mt19937-64.c \
@@ -168,6 +181,12 @@ if test "$PHP_DDTRACE" != "no"; then
     "
   fi
 
+  case "$host_os" in
+    linux*)
+      EXTRA_TRACER_SOURCES="$EXTRA_TRACER_SOURCES tracer/otel_context.c"
+      ;;
+  esac
+
   dnl datadog.c/ddtrace.c comes first, then everything else alphabetically
   DATADOG_PHP_SOURCES="$EXTRA_DATADOG_SOURCES \
     ext/datadog.c
@@ -307,10 +326,14 @@ if test "$PHP_DDTRACE" != "no"; then
   AC_CHECK_HEADER(time.h, [], [AC_MSG_ERROR([Cannot find or include time.h])])
 
   if test "$ext_shared" = "yes"; then
-    dnl Only export symbols defined in datadog.sym, which should all be marked as
+    dnl Only export the platform's listed symbols, which should all be marked as
     dnl DATADOG_PUBLIC in their source files as well.
     EXTRA_CFLAGS="$EXTRA_CFLAGS -fvisibility=hidden"
-    EXTRA_LDFLAGS="$EXTRA_LDFLAGS -export-symbols $ext_srcdir/datadog.sym -flto -fuse-linker-plugin"
+    case $host_os in
+      linux*) DDTRACE_EXPORT_SYMBOLS="$ext_srcdir/datadog-linux.sym" ;;
+      *) DDTRACE_EXPORT_SYMBOLS="$ext_srcdir/datadog.sym" ;;
+    esac
+    EXTRA_LDFLAGS="$EXTRA_LDFLAGS -export-symbols $DDTRACE_EXPORT_SYMBOLS -flto -fuse-linker-plugin"
 
     dnl On Linux: set the ELF entry point so ddtrace.so can be exec'd directly by ld.so
     dnl for sidecar spawning (no trampoline binary, no memfd, no temp files).

datadog-linux.sym

@@ -0,0 +1,46 @@
+ddtrace_close_all_spans_and_flush
+datadog_get_formatted_session_id
+ddtrace_get_profiling_context
+ddtrace_get_root_span
+datadog_process_tags_get_serialized
+datadog_get_sidecar_queue_id
+ddtrace_get_priority_sampling_on_span_zobj
+ddtrace_set_priority_sampling_on_span_zobj
+ddtrace_add_propagated_tag_on_span_zobj
+datadog_runtime_id
+ddtrace_user_req_add_listeners
+ddtrace_ip_extraction_find
+datadog_set_all_thread_vm_interrupt
+datadog_get_telemetry_rc_info
+datadog_metric_register_buffer
+datadog_metric_add_point
+ddtrace_emit_asm_event
+datadog_loaded_by_ssi
+datadog_ssi_forced_injection_enabled
+ddtrace_guess_endpoint_from_url
+ddog_remote_config_reader_for_path
+ddog_remote_config_read
+ddog_remote_config_reader_drop
+get_module
+ddog_crashtracker_entry_point
+ddog_daemon_entry_point
+ddog_set_rc_notify_fn
+ddog_remote_config_path
+ddog_remote_config_path_free
+ddog_library_configurator_new
+ddog_library_configurator_with_local_path
+ddog_library_configurator_with_fleet_path
+ddog_library_configurator_with_detect_process_info
+ddog_library_configurator_get
+ddog_library_config_source_to_string
+ddog_library_config_drop
+ddog_Error_message
+ddog_Error_drop
+ddog_library_configurator_drop
+ddog_sidecar_enqueue_telemetry_log
+ddog_sidecar_enqueue_telemetry_point
+ddog_sidecar_enqueue_telemetry_metric
+ddog_sidecar_connect
+ddog_sidecar_ping
+ddog_sidecar_transport_drop
+otel_thread_ctx_v1

ext/datadog.c

@@ -11,6 +11,7 @@
 #include "excluded_modules.h"
 #include "agent_info.h"
 #include "logging.h"
+#include "ffi_utils.h"
 #include "phpinfo.h"
 #include "process_tags.h"
 #include "remote_config.h"
@@ -547,6 +548,10 @@ static void dd_rinit_once(void) {
         datadog_process_tags_first_rinit();
         datadog_sidecar_update_process_tags();
     }
+#ifdef __linux__
+    zend_string *process_tags = datadog_process_tags_get_serialized();
+    datadog_publish_otel_process_context(dd_zend_string_to_CharSlice(process_tags));
+#endif
 
     // Uses config, cannot run earlier
 #ifndef _WIN32
@@ -704,7 +709,12 @@ static PHP_MINFO_FUNCTION(datadog) {
 
 void datadog_internal_handle_fork(void) {
     // CHILD PROCESS
+    datadog_generate_runtime_id();
     datadog_sidecar_handle_fork();
+#ifdef __linux__
+    zend_string *process_tags = datadog_process_tags_get_serialized();
+    datadog_publish_otel_process_context(dd_zend_string_to_CharSlice(process_tags));
+#endif
 
 #ifdef DDTRACE
     ddtrace_internal_handle_fork();

ext/sidecar.c

@@ -469,7 +469,11 @@ void datadog_sidecar_handle_fork(void) {
         return;
     }
 
-    datadog_force_new_instance_id();
+    if (datadog_sidecar_instance_id) {
+        ddog_sidecar_instanceId_drop(datadog_sidecar_instance_id);
+        datadog_sidecar_instance_id = NULL;
+    }
+    dd_set_resettable_sidecar_globals();
 
     // After fork only one thread (the one that called fork) survives, so we only
     // need to drop and reconnect the current thread's transport.

loader/dd_library_loader.c

@@ -322,6 +322,7 @@ injected_ext ddloader_injected_ext_config[EXT_COUNT] = {
             ZEND_MOD_OPTIONAL("ddtrace")
             ZEND_MOD_OPTIONAL("ddtrace_injected")
             ZEND_MOD_OPTIONAL("datadog-profiling")
+            ZEND_MOD_OPTIONAL("opentelemetry")
             ZEND_MOD_OPTIONAL("ev")
             ZEND_MOD_OPTIONAL("event")
             ZEND_MOD_OPTIONAL("libevent")

package.xml

@@ -75,6 +75,7 @@ ${changelog}
             <!-- code, PHP and test files -->${codefiles}
             <file name="config.m4" role="src" />
             <file name="config.w32" role="src" />
+            <file name="datadog-linux.sym" role="src" />
             <file name="datadog.sym" role="src" />
             <file name="compile_rust.sh" role="src" />
             <file name="VERSION" role="src" />

profiling/Cargo.toml

@@ -41,6 +41,10 @@ uuid = { version = "1.0", features = ["v4"] }
 [target.'cfg(target_vendor = "apple")'.dependencies]
 mach2 = "0.6.0"
 
+[target.'cfg(target_os = "linux")'.dependencies]
+libdd-library-config = { path = "../libdatadog/libdd-library-config", default-features = false, features = ["process-context-reader"] }
+libdd-trace-protobuf = { path = "../libdatadog/libdd-trace-protobuf" }
+
 [dependencies.tracing-subscriber]
 version = "0.3"
 optional = true