Imported from ekneg54/loggen-rs (AGENTS.md). Install upstream with npx skills add ekneg54/loggen-rs. Copyright stays with the author.

loggen-rs

Early-stage Rust log generator. Binary + library crate. Phase 1 (§1.1–1.2) of Plan.md is implemented; §1.3+ and Phase 2 are stubs.

Commands

cargo build                           # std build
cargo build --features kafka          # Kafka support (needs librdkafka / system lib)
cargo test                            # all tests
cargo test --lib                      # inline #[cfg(test)] tests only
cargo test --test mod                 # integration tests only (test binary name is "mod")
cargo bench                           # criterion benchmarks (harness=false)
cargo clippy --all-targets -- -D warnings   # CI-recommended lint check
cargo audit                           # CI security audit
loggen generate [--count N]           # run binary

Key modules

• src/lib.rs — re-exports all public items
• src/main.rs — clap::Parser + Subcommand derive; prog <subcommand> help workaround at main.rs:135-143
• src/cli.rs — load_base_config, apply_cli_args, create_writer, write_entries
• src/generator.rs — Generator with Tera template mode and legacy fallback; generate() returns Vec<LogEntry>, CLI uses streaming generate_to_writer()
• src/config.rs — Config, OutputConfig, LogEntry, YAML deser via serde_yaml
• src/output.rs — LogWriter trait, StdoutWriter, FileWriter (append by default, configurable truncate + rotate_bytes), BufferedLogWriter, HttpWriter (full impl with batching/retry), KafkaWriter (feature-gated via --features kafka), ProgressReporter

Quirks

• --output flag sets target: "file" automatically (cli.rs:43-49)
• FileWriter default is append mode (never truncates unless output.append: false)
• Template validation panics at Generator::new() on unknown variables
• Streaming has 3 paths: write_legacy_stream (sequential), write_template_stream (sequential), write_template_parallel_stream (rayon via mpsc, only when random_intensity >= 1.0 and no simulation)
• Simulation mode (sim_delay, sim_rotation) makes streaming infinite (until Ctrl+C via ctrlc)
• ProgressReporter auto-enables when count >= 100,000 and target != stdout
• Default config.count is 1 (not user-friendly but deliberate)
• config.seed enables reproducible output; no seed = random
• Config::has_templates() is the canonical template-mode check
• Cargo.lock is committed despite being in .gitignore — keep both
• Container image via nix build .#container (Nix flake)
• Release workflow cross-compiles 4 targets + container via Nix (ghcr.io)

Testing

• Inline tests (#[cfg(test)]) in config.rs, generator.rs, output.rs
• Integration tests in tests/unit/ (wired via tests/mod.rs)
• Tests write files to CWD (no tempfile crate): test_config*.yaml, test_output*.log, test_new_file.log, test_template_mode.log, test_cli_gen.log, output.log
• Integration tests at tests/unit/test_config.rs read from examples/ — must run from repo root
• Benchmarks: benches/benchmarks.rs via criterion

Dependencies

clap (derive), clap_complete, serde/serde_yaml, tera, rand, rayon, regex, chrono, ureq (HTTP), serde_json, ctrlc. Optional: rdkafka behind kafka feature.

Security history

StdoutWriter::template_mode, FileWriter::template_mode, and all BufferedLogWriter fields are pub(crate) (were pub in earlier versions). Public setter methods (set_template_mode) were added for external consumers.