ZeroTierOne/ext/opentelemetry-cpp-1.21.0/docs/dependencies.md
2025-07-11 10:37:21 -07:00

101 lines
4.1 KiB
Markdown

# Dependencies and Licenses
There are
- External dependencies as linkable libraries or externally installed headers, and
- Internal dependencies as the part of code from external libraries
backported/copied in main repo.
Both these dependencies are listed here:
## Internal dependencies
- [nostd::variant](/api/include/opentelemetry/nostd/internal/absl/types/variant.h):
This is backported from [Abseil C++
libraries](https://github.com/abseil/abseil-cpp) and used as default variant
implementation. License: `Apache License 2.0`
- [TraceLoggingDynamic](/exporters/etw/include/opentelemetry/exporters/etw/TraceLoggingDynamic.h):
Dynamic TraceLogging Provider API for C++ used by ETW exporter. License: `MIT License`
## External dependencies
- [API](/api)
&
[SDK](/sdk):
- Uses Standard C++ library for latest features (std::string_view,
std::variant, std::span, std::shared_ptr, std::unique_ptr) with C++14/17/20
compiler if cmake option `WITH_STL` is enabled
or macro `OPENTELEMETRY_STL_VERSION` is defined.
License: `GNU General Public License`
- For C++14/17 compilers, fallback to gsl::span if [GSL C++
library](https://github.com/microsoft/GSL) is installed. License: `MIT
License`
- libc++ 14.0.0 do not support construct std::span from a range or container
.We don't use the std::span in this situation.Users can also define
`OPENTELEMETRY_OPTION_USE_STD_SPAN=0` to indicate nostd:span will always
not be a alias for std::span.
- [OTLP/HTTP+JSON](/exporters/otlp)
exporter:
- [protobuf](https://github.com/protocolbuffers/protobuf): Library to
serialize structured data.
- OTLP messages are constructed as protobuf payloads.
- `protoc` compiler is used to generate C++ stubs for proto files provided
by `opentelemetry-proto`.
- `libprotobuf` library is used for generating serialized trace/metrics/log
data to be sent to opentelemetry collector.
- License: The library is licensed
[here](https://github.com/protocolbuffers/protobuf/blob/master/LICENSE).
The code generated by protoc compiler is owned by the owner of `.proto`
file.
- [libcurl](https://curl.se/libcurl/) : the multiprotocol file transfer
library.
- Export connects with opentelemetry collector over HTTP protocol using
libcurl library
- License: Inspired by `MIT/X` but not same.
<https://curl.se/docs/copyright.html>
- [nlohmann/json](https://github.com/nlohmann/json): JSON for Modern C++.
- protobuf serialized otlp messages are encoded in JSON format using this
library.
- License: `MIT License`
- [zlib](https://www.zlib.net/): A Massively Spiffy Yet Delicately
Unobtrusive Compression Library.
- The `http_client` utilizes zlib to compress the message body and send
it in gzip format.
- License: The library is licensed
[here](https://www.zlib.net/zlib_license.html)
- [OTLP/gRPC](/exporters/otlp)
exporter:
- `protobuf` OTLP messages are constructed as protobuf payloads.
- [gRPC](https://github.com/grpc/grpc): An RPC library and framework
- Exporter communicates with OTLP collector using gRPC transport mechanism.
- License: `Apache License 2.0`
- [Zipkin](/exporters/zipkin)
exporter:
- `libcurl` for connecting with Zipkin server over HTTP protocol.
- `nlohmann/json` for encoding Zipkin messages.
- [ETW](/exporters/etw)
exporter:
- `nlohmann/json` for generating MessagePack serialization for message to be
transmitted to ETW.
- [Prometheus](/exporters/prometheus)
exporter:
- [`prometheus-cpp`](https://github.com/jupp0r/prometheus-cpp) Prometheus
Client Library for Modern C++
- License: `MIT License`
- [ElasticSearch](/exporters/elasticsearch)
exporter:
- `libcurl` for connecting with Elasticsearch server over HTTP protocol.
- `nlohmann/json` for encoding Elastic Search messages.
- [Opentracing](/opentracing-shim)
shim:
- [`opentracing-cpp`](https://github.com/opentracing/opentracing-cpp)
OpenTracing API for C++
- A bridge layer implementing the OpenTracing API using the OpenTelemetry API
- License: `Apache License 2.0`