ZeroTierOne/ext/opentelemetry-cpp-1.21.0/CONTRIBUTING.md

Contributing to opentelemetry-cpp

The OpenTelemetry C/C++ special interest group (SIG) meets regularly. See the OpenTelemetry community repo for information on this and other language SIGs.

See the public meeting notes for a summary description of past meetings. To request edit access, join the meeting or get in touch on Slack.

See the community membership document on how to become a Member, Approver and Maintainer.

Development

OpenTelemetry C++ uses the Google naming convention.

Code is formatted automatically and enforced by CI.

Build and Run Code Examples

Note: these instructions apply to examples configured with Bazel, see example-specific documentation for other build automation tools.

Install the latest bazel version by following the steps listed here.

Select an example of interest from the examples folder. Inside each example directory is a BUILD file containing instructions for Bazel. Find the binary name of your example by inspecting the contents of this BUILD file.

Build the example from the root of the opentelemetry-cpp directory using Bazel. Replace <binary name> with the identifier found in the previous step:

bazel build //examples/<example directory name>:<binary name>

Run the resulting executable to see telemetry from the application as it calls the instrumented library:

bazel-bin/examples/<example directory name>/<binary name>

For instance, building and running the simple example can be done as follows:

bazel build //examples/simple:example_simple
bazel-bin/examples/simple/example_simple

DevContainer Setup for Project

This guide provides instructions on how to set up and use the development container (devcontainer) environment to streamline testing and development for this project. With the DevContainer, you can work in a consistent environment configured with all the necessary dependencies and tools.

Prerequisites

Before getting started, ensure you have the following installed:

• Docker: DevContainers require Docker for containerization.
• Visual Studio Code (VSCode) with the Remote - Containers extension.

Getting Started

• Open the Project in DevContainer:

Open the project in VSCode. When prompted to "Reopen in Container," select this option. If you’re not prompted, you can manually open the container by selecting Remote-Containers: Reopen in Container from the command palette (F1 or Ctrl+Shift+P).

• Container Setup:

The DevContainer environment will automatically build based on the configuration files provided (e.g., .devcontainer/devcontainer.json). This setup will install required dependencies, tools, and environment variables needed for the project.

• Container Customization: See .devcontainer/README.md for devcontainer configuration options.

Available Commands

Once inside the DevContainer, you can use the following commands to run tests and CI workflows.

1. Run Tests with Bazelisk

To run tests with Bazelisk using specific compilation options, use:

bazelisk-linux-amd64 test --copt=-DENABLE_LOGS_PREVIEW
--test_output=errors --cache_test_results=no --copt=-DENABLE_TEST //exporters/otlp/...

Command Breakdown

• --copt=-DENABLE_LOGS_PREVIEW: Enables preview logs.
• --test_output=errors: Shows only the errors in the test output.
• --cache_test_results=no: Forces Bazel to re-run tests without caching.
• --copt=-DENABLE_TEST: Enables testing capabilities for the target code.
• //exporters/otlp/...: Specifies the test target path.

2. Run CI Script

You can also run the CI script provided to perform testing with the following command as an example:

bash ci/do_ci.sh cmake.exporter.otprotocol.test

This command initiates the CI pipeline, executing tests specifically for the cmake.exporter.otprotocol module.

Troubleshooting

If you encounter issues:

• Rebuild the DevContainer: From the command palette, run Remote-Containers: Rebuild Container to reinitialize the environment.
• Check Bazelisk and CI Script Logs: Inspect logs for any configuration or dependency issues.

Additional Notes

• You can adjust compiler options (--copt) as needed to test additional flags or enable/disable specific features.
• The test results will be displayed in the terminal within the DevContainer for easy debugging.

Resources

• Bazelisk Documentation: https://github.com/bazelbuild/bazelisk
• VSCode DevContainer Documentation: https://code.visualstudio.com/docs/remote/containers

Docker Development Image

The .devcontainer/Dockerfile.dev dockerfile can be built directly with the following command.

 docker build -t opentelemetry-cpp-dev -f ./.devcontainer/Dockerfile.dev .

You can customize the image using build arguments to match permissions with the host user.

 docker build -t opentelemetry-cpp-dev \
  --build-arg USER_UID="$(id -u)" \
  --build-arg USER_GID="$(id -g)" \
  -f ./.devcontainer/Dockerfile.dev .

Run an interactive bash session binding your host opentelemetry-cpp directory to the container's workspace:

docker run -it -v "$PWD:/workspaces/opentelemetry-cpp" opentelemetry-cpp-dev bash

Pull Requests

How to Send Pull Requests

Everyone is welcome to contribute code to opentelemetry-cpp via GitHub pull requests (PRs).

To create a new PR, fork the project in GitHub and clone the upstream repo:

git clone --recursive https://github.com/open-telemetry/opentelemetry-cpp.git

Add your fork as a remote:

git remote add fork https://github.com/YOUR_GITHUB_USERNAME/opentelemetry-cpp.git

If you haven't, make sure you are loading the submodules required to build OpenTelemetry

git submodule init
git submodule update

The source code is automatically formatted using clang-format.

The output can vary between versions, so make sure to install clang-format version 10.0, and have clang-format-10 in your execution path, so that the helper script tools/format.sh can find it.

Check out a new branch, make modifications and push the branch to your fork:

git checkout -b feature
# edit files
tools/format.sh
git commit
git push fork feature

If you made changes to the Markdown documents (*.md files), install the latest markdownlint-cli and run:

markdownlint .

If you modified shell scripts (*.sh files), install shellcheck and run:

shellcheck --severity=error <path to shell script>.sh

Open a pull request against the main opentelemetry-cpp repo.

To run tests locally, please read the CI instructions.

How to Receive Comments

• If the PR is not ready for review, please put [WIP] in the title, tag it as work-in-progress, or mark it as draft.
• Make sure CLA is signed and CI is clear.
• For non-trivial changes, please update the CHANGELOG.

How to Get PRs Merged

A PR is considered to be ready to merge when:

• It has received two approvals with at least one approval from Approver / Maintainer (at different company).
• A pull request opened by an Approver / Maintainer can be merged with only one approval from Approver / Maintainer (at different company).
• Major feedback items/points are resolved.
• It has been open for review for at least one working day. This gives people reasonable time to review.
• Trivial changes (typo, cosmetic, doc, etc.) don't have to wait for one day.
• Urgent fixes can take exceptions as long as it has been actively communicated.

Any Maintainer can merge the PR once it is ready to merge. Maintainer can make conscious judgement to merge pull requests which have not strictly met above mentioned requirements.

If a PR has been stuck (e.g. there are lots of debates and people couldn't agree on each other), the owner should try to get people aligned by:

• Consolidating the perspectives and putting a summary in the PR. It is recommended to add a link into the PR description, which points to a comment with a summary in the PR conversation
• Stepping back to see if it makes sense to narrow down the scope of the PR or split it up.

If none of the above worked and the PR has been stuck for more than 2 weeks, the owner should bring it to the OpenTelemetry C++ SIG meeting. See README.md for the meeting link.

Design Choices

As with other OpenTelemetry clients, opentelemetry-cpp follows the opentelemetry-specification.

It's especially valuable to read through the library guidelines.

Useful Resources

Hi! If you’re looking at this document, these resources will provide you the knowledge to get started as a newcomer to the OpenTelemetry project. They will help you understand the OpenTelemetry Project, its components, and specifically the C++ repository.

Reading Resources

• Medium article (October 2019) on how to start contributing to the OpenTelemetry project.
• Medium article (January 2020) describing the overarching goals and use cases for OpenTelemetry.

Relevant Documentation

• OpenTelemetry Specification

• The OpenTelemetry Specification describes the requirements and expectations of for all OpenTelemetry implementations.

• Read through the OpenTelemetry C++ documentation

• The API and SDK documentation provides a lot of information on what the classes and their functions are used for.

Please contribute! You’re welcome to add more information if you come across any helpful resources.