i2pd‑exporter

Tiny, pure‑Rust Prometheus exporter for the i2pd (C++) router via I2PControl JSON‑RPC (API=1). Not compatible with the Java I2P router.

• Serves metrics at /metrics (default listen: 0.0.0.0:9600)
• Handles token auth and retries once on token errors
• Exposes router metrics (status, uptime, bandwidth, IPv4/IPv6 network status, tunnels, NetDB, totals) + exporter self‑metrics
• Small static binary (LTO, stripped)

Quick start

# Build
cargo build --release

# Version
./target/release/i2pd-exporter --version

# Run (defaults to https://127.0.0.1:7650 for I2PControl)
RUST_LOG=info ./target/release/i2pd-exporter

Optional cross‑build for Linux (x86_64): ./build-linux-docker.sh → ./dist/i2pd-exporter.

Configuration

Provide the base I2PControl URL without /jsonrpc. The exporter appends /jsonrpc.

TLS tip: Self‑signed loopback (127.0.0.1/localhost) is automatically allowed; for remote HTTPS targets, prefer proper certificates.

HTTP

• GET /: → 404 Not Found

• GET /metrics → OpenMetrics text format

  • Content-Type: application/openmetrics-text; version=1.0.0; charset=utf-8
  • Cache-Control: no-store

Note: The server always emits OpenMetrics text (1.0.0). Prometheus and many agents request this via Accept: application/openmetrics-text;version=1.0.0. Some browsers may download the response rather than rendering it inline if OpenMetrics is not explicitly accepted.

Scrape timeout (required header)

Prometheus must send X-Prometheus-Scrape-Timeout-Seconds. The exporter computes:

candidate = (header_secs > 3.0) ? header_secs - 0.5 : header_secs
effective = min(candidate, MAX_SCRAPE_TIMEOUT_SECONDS)
effective is clamped to >= 0.1s

• Missing/invalid header → 400 Bad Request
• Budget exceeded → 504 Gateway Timeout
• Self‑metrics always include the computed budget.

Metrics (overview)

Router:

• i2p_router_status
• i2p_router_build_info{version}
• i2p_router_uptime_seconds
• i2p_router_net_bw_bytes_per_second{direction,window} (inbound,outbound,transit; 1s,15s)
• i2p_router_net_status{state} + i2p_router_net_status_code (IPv4+IPv6, includes stan)
• i2p_router_net_error{error} + i2p_router_net_error_code (IPv4+IPv6)
• i2p_router_net_testing / i2p_router_net_testing_v6
• i2p_router_tunnels_participating, _inbound, _outbound, _queue, _tbmqueue, _success_ratio, _total_success_ratio
• i2p_router_netdb_activepeers, _knownpeers, _floodfills, _leasesets
• i2p_router_net_bytes_total{direction} (inbound,outbound,transit)

Exporter:

• i2pd_exporter_build_info{version}
• i2pd_exporter_scrape_duration_seconds
• i2pd_exporter_effective_scrape_timeout_seconds
• i2pd_exporter_last_scrape_error

Development

pre-commit runs the project checks locally:

• cargo fmt --all -- --check
• cargo check --all-targets --all-features
• cargo clippy --all-targets --all-features -- -D warnings
• cargo test --all-targets --all-features

Install the git hook with pre-commit install. Run everything manually with pre-commit run --all-files.

Releases

GitHub Releases include prebuilt Linux archives for x86_64-unknown-linux-gnu and aarch64-unknown-linux-gnu, plus sha256sums.txt.

License

MIT