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nikhilbhatia08nikhilbhatia08
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[resource_detectors] implementation of process resource detector as per semconv (open-telemetry#3591)
* [resource_detectors] implementation of process resource detector as per semconv * removed unclear changes * fixes suggested by copilot * disable clang-format for windows * test addition and details folder * test for GetCommand and format fix * minor error fix * todo for darwin * buffer len fix ---------
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13 files changed

+444
-7
lines changed

13 files changed

+444
-7
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‎resource_detectors/BUILD‎

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@@ -14,7 +14,10 @@ cc_library(
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srcs = [
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"container_detector.cc",
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"container_detector_utils.cc",
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"process_detector.cc",
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"process_detector_utils.cc",
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],
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copts = ["-fexceptions"],
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deps = [
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"//api",
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"//resource_detectors:headers",

‎resource_detectors/CMakeLists.txt‎

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# Copyright The OpenTelemetry Authors
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# SPDX-License-Identifier: Apache-2.0
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add_library(opentelemetry_resource_detectors container_detector_utils.cc
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container_detector.cc)
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add_library(
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opentelemetry_resource_detectors
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container_detector_utils.cc container_detector.cc process_detector.cc
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process_detector_utils.cc)
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set_target_properties(opentelemetry_resource_detectors
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PROPERTIES EXPORT_NAME resource_detectors)
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PATTERN
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"*.h"
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PATTERN
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"container_detector_utils.h"
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"resource_detectors/detail/*"
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EXCLUDE)
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if(BUILD_TESTING)

‎resource_detectors/container_detector.cc‎

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#include "opentelemetry/resource_detectors/container_detector.h"
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#include "opentelemetry/nostd/variant.h"
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#include "opentelemetry/resource_detectors/container_detector_utils.h"
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#include "opentelemetry/resource_detectors/detail/container_detector_utils.h"
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#include "opentelemetry/sdk/resource/resource.h"
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#include "opentelemetry/sdk/resource/resource_detector.h"
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#include "opentelemetry/semconv/incubating/container_attributes.h"

‎resource_detectors/container_detector_utils.cc‎

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// Copyright The OpenTelemetry Authors
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// SPDX-License-Identifier: Apache-2.0
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#include "opentelemetry/resource_detectors/container_detector_utils.h"
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#include "opentelemetry/resource_detectors/detail/container_detector_utils.h"
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#include "opentelemetry/nostd/string_view.h"
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#include <fstream>

‎resource_detectors/include/opentelemetry/resource_detectors/container_detector_utils.h‎ renamed to ‎resource_detectors/include/opentelemetry/resource_detectors/detail/container_detector_utils.h‎

File renamed without changes.

‎resource_detectors/include/opentelemetry/resource_detectors/detail/process_detector_utils.h‎

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// Copyright The OpenTelemetry Authors
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// SPDX-License-Identifier: Apache-2.0
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#pragma once
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#include <stdint.h>
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#include <string>
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#include "opentelemetry/version.h"
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OPENTELEMETRY_BEGIN_NAMESPACE
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namespace resource_detector
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{
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namespace detail
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{
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/**
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* Forms a file path for a process type based on the given PID.
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* for example - /proc/<pid>/cmdline, /proc/<pid>/exe
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*/
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std::string FormFilePath(const int32_t &pid, const char *process_type);
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/**
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* Retrieves the absolute file system path to the executable for a given PID.
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* Platform-specific behavior:
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* - Windows: Uses OpenProcess() + GetProcessImageFileNameW().
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* - Linux/Unix: Reads the /proc/<pid>/exe symbolic link.
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* - TODO: Need to implement for Darwin
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*
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* @param pid Process ID.
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*/
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std::string GetExecutablePath(const int32_t &pid);
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/**
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* Retrieves the command used to launch the process for a given PID.
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* Platform-specific behavior:
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* - Windows: Uses GetCommandLineW() to get the command of the current process.
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* - Linux/Unix: Reads the zeroth string of /proc/<pid>/cmdline file.
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* - TODO: Need to implement for Darwin
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*/
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std::string ExtractCommand(const std::string &command_line_path);
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/**
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* Retrieves the command used to launch the process for a given PID.
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* This function is a wrapper around ExtractCommand() and is provided for convenience and
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* testability of ExtractCommand().
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*/
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std::string GetCommand(const int32_t &pid);
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} // namespace detail
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} // namespace resource_detector
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OPENTELEMETRY_END_NAMESPACE

‎resource_detectors/include/opentelemetry/resource_detectors/process_detector.h‎

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// Copyright The OpenTelemetry Authors
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// SPDX-License-Identifier: Apache-2.0
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#pragma once
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#include "opentelemetry/sdk/resource/resource.h"
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#include "opentelemetry/sdk/resource/resource_detector.h"
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#include "opentelemetry/version.h"
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OPENTELEMETRY_BEGIN_NAMESPACE
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namespace resource_detector
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{
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/**
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* ProcessResourceDetector to detect resource attributes when running in a process.
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* This detector extracts metadata such as process ID, executable path, and command line arguments
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* and sets attributes like process.pid, process.executable.path, and process.command following
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* the OpenTelemetry semantic conventions.
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*/
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class ProcessResourceDetector : public opentelemetry::sdk::resource::ResourceDetector
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{
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public:
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/**
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* Detect retrieves the resource attributes for the current process.
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* It reads:
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* - process.pid from the current process ID
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* - process.executable.path from the executable path of the current process
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* - process.command from the command used to launch the process
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* and returns a Resource with these attributes set.
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*/
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opentelemetry::sdk::resource::Resource Detect() noexcept override;
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};
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} // namespace resource_detector
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OPENTELEMETRY_END_NAMESPACE

‎resource_detectors/process_detector.cc‎

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// Copyright The OpenTelemetry Authors
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// SPDX-License-Identifier: Apache-2.0
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#include "opentelemetry/resource_detectors/process_detector.h"
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#include "opentelemetry/nostd/variant.h"
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#include "opentelemetry/resource_detectors/detail/process_detector_utils.h"
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#include "opentelemetry/sdk/common/global_log_handler.h"
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#include "opentelemetry/sdk/resource/resource.h"
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#include "opentelemetry/sdk/resource/resource_detector.h"
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#include "opentelemetry/semconv/incubating/process_attributes.h"
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#include "opentelemetry/version.h"
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#include <stdint.h>
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#include <exception>
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#include <ostream>
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#include <string>
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#include <unordered_map>
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#include <utility>
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#ifdef _MSC_VER
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# include <process.h>
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# define getpid _getpid
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#else
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# include <unistd.h>
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#endif
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OPENTELEMETRY_BEGIN_NAMESPACE
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namespace resource_detector
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{
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opentelemetry::sdk::resource::Resource ProcessResourceDetector::Detect() noexcept
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{
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int32_t pid = getpid();
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opentelemetry::sdk::resource::ResourceAttributes attributes;
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attributes[semconv::process::kProcessPid] = pid;
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try
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{
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std::string executable_path = opentelemetry::resource_detector::detail::GetExecutablePath(pid);
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if (!executable_path.empty())
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{
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attributes[semconv::process::kProcessExecutablePath] = std::move(executable_path);
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}
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}
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catch (const ::std::exception &ex)
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{
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OTEL_INTERNAL_LOG_ERROR("[Process Resource Detector] "
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<< "Error extracting the executable path: " << ex.what());
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}
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try
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{
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std::string command = opentelemetry::resource_detector::detail::GetCommand(pid);
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if (!command.empty())
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{
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attributes[semconv::process::kProcessCommand] = std::move(command);
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}
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}
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catch (const std::exception &ex)
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{
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OTEL_INTERNAL_LOG_ERROR("[Process Resource Detector] " << "Error extracting command: "
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<< ex.what());
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}
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return ResourceDetector::Create(attributes);
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}
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} // namespace resource_detector
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OPENTELEMETRY_END_NAMESPACE

‎resource_detectors/process_detector_utils.cc‎

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// Copyright The OpenTelemetry Authors
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// SPDX-License-Identifier: Apache-2.0
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#include "opentelemetry/resource_detectors/detail/process_detector_utils.h"
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#include <fstream>
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#include <string>
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#ifdef _MSC_VER
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// clang-format off
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# include <windows.h>
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# include <psapi.h>
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// clang-format on
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#else
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# include <sys/types.h>
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# include <unistd.h>
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# include <cstdio>
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#endif
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#include "opentelemetry/version.h"
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OPENTELEMETRY_BEGIN_NAMESPACE
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namespace resource_detector
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{
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namespace detail
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{
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constexpr const char *kExecutableName = "exe";
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constexpr const char *kCmdlineName = "cmdline";
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std::string GetExecutablePath(const int32_t &pid)
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{
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#ifdef _MSC_VER
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HANDLE hProcess =
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OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, static_cast<DWORD>(pid));
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if (!hProcess)
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{
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return std::string();
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}
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WCHAR wbuffer[MAX_PATH];
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DWORD len = GetProcessImageFileNameW(hProcess, wbuffer, MAX_PATH);
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CloseHandle(hProcess);
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if (len == 0)
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{
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return std::string();
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}
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// Convert UTF-16 to UTF-8
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int size_needed = WideCharToMultiByte(CP_UTF8, 0, wbuffer, len, NULL, 0, NULL, NULL);
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std::string utf8_path(size_needed, 0);
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WideCharToMultiByte(CP_UTF8, 0, wbuffer, len, &utf8_path[0], size_needed, NULL, NULL);
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return utf8_path;
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#else
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std::string path = FormFilePath(pid, kExecutableName);
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char buffer[4096];
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ssize_t len = readlink(path.c_str(), buffer, sizeof(buffer) - 1);
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if (len != -1)
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{
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buffer[len] = '\0';
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return std::string(buffer);
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}
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return std::string();
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#endif
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}
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std::string GetCommand(const int32_t &pid)
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{
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#ifdef _MSC_VER
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// On Windows, GetCommandLineW only works for the CURRENT process,
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// so we ignore `pid` and just return the current process's command line.
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LPCWSTR wcmd = GetCommandLineW();
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if (!wcmd)
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{
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return std::string();
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}
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// Convert UTF-16 to UTF-8
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int size_needed = WideCharToMultiByte(CP_UTF8, 0, wcmd, -1, NULL, 0, NULL, NULL);
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if (size_needed <= 0)
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{
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return std::string();
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}
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std::string utf8_command(size_needed - 1, 0); // exclude null terminator
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WideCharToMultiByte(CP_UTF8, 0, wcmd, -1, &utf8_command[0], size_needed, NULL, NULL);
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return utf8_command;
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#else
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// This is the path to get the command that was used to start the process
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std::string command_line_path = FormFilePath(pid, kCmdlineName);
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return ExtractCommand(command_line_path);
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#endif
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}
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std::string ExtractCommand(const std::string &command_line_path)
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{
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std::string command;
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std::ifstream command_line_file(command_line_path, std::ios::in | std::ios::binary);
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std::getline(command_line_file, command, '\0');
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return command;
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}
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std::string FormFilePath(const int32_t &pid, const char *process_type)
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{
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char buff[64];
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int len = std::snprintf(buff, sizeof(buff), "/proc/%d/%s", pid, process_type);
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if (len < 0)
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{
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// in case snprintf fails
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return std::string();
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}
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if (len >= static_cast<int>(sizeof(buff)))
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{
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return std::string(buff, sizeof(buff) - 1);
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}
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return std::string(buff, len);
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}
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} // namespace detail
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} // namespace resource_detector
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OPENTELEMETRY_END_NAMESPACE

‎resource_detectors/test/BUILD‎

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name = "resource_detector_test",
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srcs = [
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"container_detector_test.cc",
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"process_detector_test.cc",
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],
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tags = ["test"],
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deps = [

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