with vcpkg install opentelemetry-cpp[otlp_http], no libopentelemetry_exporter_otlp_http.a or exporters/otlp/*.h

[jodavaho]

Describe your environment

Distributor ID: Ubuntu
Description: Ubuntu 20.04.5 LTS
Release: 20.04
Codename: focal

vcpkg package management program version 2023-01-24-8a88d63f241d391772fbde69af9cab96c3c64c75

I am compiling just the http_main.cc file from examples/otlp/http_main.cc in a new project that uses vcpkg to satisfy dependencies, to test the vcpkg route to see if that works better than building/installing from source.

vcpkg.json:

{
  "name": "test-otel",
    "version-string": "0.1.0",
    "dependencies": [
    {
      "name": "opentelemetry-cpp",
      "default-features": true,
      "features":["otlp-http"]
    },
    "abseil",
    "protobuf"
    ]
}

Steps to reproduce

mkdir build && cd build
cp ~/<path to opentelemetry-cpp>/examples/otlp/http_main.cc ../src/main.cpp
#... make any old ../CMakeLists.txt that has
# find_package(opentelemetry-cpp CONFIG REQUIRED)
cmake .. -DCMAKE_TOOLCHAIN_FILE=~/<path to vcpkg>/scripts/buildsystems/vcpkg.cmake
... vcpkg does its thing ...
$ tree ../vcpkg_installed/x64-linux/include/opentelemetry/exporters/
../vcpkg_installed/x64-linux/include/opentelemetry/exporters/
├── memory
│   ├── in_memory_data.h
│   ├── in_memory_span_data.h
│   ├── in_memory_span_exporter_factory.h
│   └── in_memory_span_exporter.h
└── ostream
    ├── common_utils.h
    ├── log_record_exporter.h
    ├── metric_exporter.h
    ├── span_exporter_factory.h
    └── span_exporter.h

What is the expected behavior?

$ tree ../vcpkg_installed/x64-linux/include/opentelemetry/exporters/
../vcpkg_installed/x64-linux/include/opentelemetry/exporters/
├── otlp
│   └── otlp_http_exporter.h (etc)
├── memory
│   ├── in_memory_data.h
│   ├── in_memory_span_data.h
│   ├── in_memory_span_exporter_factory.h
│   └── in_memory_span_exporter.h
└── ostream
    ├── common_utils.h
    ├── log_record_exporter.h
    ├── metric_exporter.h
    ├── span_exporter_factory.h
    └── span_exporter.h

What is the actual behavior?

• no otlp_http related headers installed
• no libopentelemetry_exporter_otlp_http.a (or .so)

Additional context
Similar to #1975 , I suspect the exporter will not be built unless I also include opentelemetry-cpp[otlp,otlp_http], but that is highly undesirable because it pulls grpc, which is currently a showstopper for various reasons. Since grpc is not actually required, there should be a mutually exclusive option for http.

[jodavaho]

Side question from ignorance: Without exporters and headers, what am I actually pulling when I ask for otlp_http?

[lalitb]

Moving this to discussion, as the otel-cpp vcpkg is not officially distributed by OpenTelemetry C++. @ThomsonTan has created the latest vcpkg port v1.8.2, so he may be able to help here.

Without exporters and headers, what am I actually pulling when I ask for otlp_http?

It should bring exporter and it's headers.

[lalitb]

Oh my bad. We still need #1926 to get fixed, before this cleanup works properly. If vcpkg is broken for otlp-http, I don't know if Tom will have time to fix this before next release. Please feel free to raise a bug on vcpkg repo, and assign it to Tom.

[ThomsonTan]

I just tried the latest vcpkg with opentelemetry 1.8.2 (I did it on Windows, but assume Linux should have the same behavior). And grpc is not installed as dependency, so opentelemetry-cpp[otlp-http] only installs HTTP dependency. Is this the ask here?

vcpkg install opentelemetry-cpp[otlp-http]:x64-windows-static
dir /s/b otlp_http_exporter*
C:\gh\vcpkg\buildtrees\opentelemetry-cpp\src\v1.8.2-19a2a784eb.clean\exporters\otlp\include\opentelemetry\exporters\otlp\otlp_http_exporter.h

[jodavaho]

optenelemetry-cpp[otlp-http] does not install headers or libraries for the otlp_http functionality.

Try:

$ tree ../vcpkg_installed/x64-linux/include/opentelemetry/exporters/
../vcpkg_installed/x64-linux/include/opentelemetry/exporters/
├── otlp
│   └── otlp_http_exporter.h (< -- not present!)
├── memory
│   ├── in_memory_data.h
│   ├── in_memory_span_data.h
│   ├── in_memory_span_exporter_factory.h
│   └── in_memory_span_exporter.h
└── ostream
    ├── common_utils.h
    ├── log_record_exporter.h
    ├── metric_exporter.h
    ├── span_exporter_factory.h
    └── span_exporter.h

[jodavaho]

opentelemetry-cpp[otlp-http] is syntactically equivalent to WITH_OTLP_HTTP=On, but that essentially provides nothing. The correct flags to get the http exporter without grpc is for some reason WITH_OTLP=On WITH_OTLP_HTTP=On WITH_OTLP_GRPC=Off and that won't change, apparently. #1975 #1978

But there is no way to specify those three flags to vcpkg just get otlp-http, which is the pretty-obvious requirement when specifying opentelemetry-cpp[otlp-http]

[willie]

Did you ever find a workaround?