Go practices

Go concurrency exercises, an HTTP client example, and a JWT-protected HTTP server. The repository uses one module, github.com/jaysonhurd/go-practices, with Go 1.24.2 or later. Run commands from the repository root.

Examples

go run ./concurrency/channels
go run ./concurrency/waitgroups
go run ./concurrency/worker

The waitgroups example requires fixtures/1mb-examplefile-com.txt, which is not included; supply that fixture before running it.

Concurrency examples read text under fixtures/ and print to stdout. Their structured application logs are appended to logs/go-practices.log. These are learning exercises, not production worker services; the channel example has a ten-second deadline and deliberately delays output.

For the HTTP client example, supply your own Polygon credential through POLYGON_API_KEY, then run go run ./httpmusings. It listens on port 8080 and proxies the previous-close response for AAPL. The API key is never stored in code. The client uses a ten-second timeout and releases response bodies. Unit tests inject ClientDoer without reaching Polygon. The existing handler response behavior is preserved, including an empty response when the upstream call fails. A credential previously embedded in source should be rotated with its provider; removing it here does not remove it from Git history.

See HTTP server usage for JWT configuration, routes, and graceful shutdown. It also listens on port 8080, so run the HTTP examples separately.

Observability and compatibility

All executables use log/slog with JSON file output under logs/. Generated logs, local .codex/ state, IDE files, and JSON files are ignored. No JSON exceptions are currently required. go.sum remains versioned for reproducible dependency checks.

HTTP executables initialize OpenTelemetry tracing and request metrics. Set OTEL_STDOUT_ENABLED=true to export JSON traces and metrics to stdout (otherwise no telemetry is exported). Exporters are flushed during normal executable cleanup; both HTTP servers drain requests first. No collector or credentials are needed. Spans use a fixed name; metrics label only normalized HTTP methods. Request URLs, headers, and JWT claims are excluded. No global provider is replaced.

OpenTelemetry Go v1.35.0 API, SDK, and stdout exporters provide this opt-in instrumentation while retaining Go 1.24.2 compatibility. These are new production dependencies; zerolog is removed. JSON continues to use encoding/json because encoding/json/v2 is unavailable on the declared minimum toolchain. No Go upgrade or experiment is enabled.

Validation

Prerequisites: Go 1.24.2+ (go and gofmt on PATH), Python 3.9+, Git, and Bash. There are no external-service requirements or build tags for tests.

python3 scripts/validate.py

This runs Python checker regression tests, repository structure checks, formatting checks, and go build ./..., go test -race -cover ./..., and go vet ./... in every discovered nonignored Go module. Formatting failures do not modify files. For targeted work, use native Go commands from the module root:

go build ./...
go test -race -cover ./...
go vet ./...
python3 -m unittest discover -s scripts -p 'test_*.py'
python3 scripts/check_repository.py

The structural checker covers tracked and new nonignored files. It checks basic single-line skill frontmatter, inline local Markdown links and heading anchors, and Bash syntax for .sh scripts. It does not check remote links, full YAML, reference-style Markdown links, or skill behavior. Ignored local .codex/ skills are not distributed or checked by CI. Vendored sources are excluded from Go formatting and module discovery. Tests report coverage; 95% is a goal, not an artificial pass threshold for executable examples and lifecycle error branches.

GitHub Actions runs the same validation command for pull requests to and pushes to main. Its stable check name is Repository validation, with read-only token permissions, a timeout, SHA-pinned Actions, and no persisted checkout credentials. Remote branch protections and security settings are not configured by these files.

See project instructions. The original README's personal-preferences installation guide is preserved as reference documentation.