chore: pre-release gap fixes

.github/workflows/ci.yaml

@@ -16,7 +16,7 @@ jobs:
         go-version-file: go.mod
     - uses: golangci/golangci-lint-action@1e7e51e771db61008b38414a730f564565cf7c20 # v9.2.0
       with:
-        version: v2.5.0
+        version: v2.11.3
 
   test:
     runs-on: ubuntu-latest

Makefile

@@ -0,0 +1,48 @@
+# Makefile for github.com/zakame/speedtest-go-exporter
+
+BINARY      := speedtest-go-exporter
+CMD         := ./cmd/$(BINARY)
+BIN_DIR     := ./bin
+CGO_ENABLED ?= 0
+
+.DEFAULT_GOAL := help
+
+.PHONY: help build test cover lint vet fmt run clean
+
+help: ## Show this help message
+	@echo "Usage: make <target>"
+	@echo ""
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) \
+		| sort \
+		| awk 'BEGIN {FS = ":.*?## "}; {printf "  \033[36m%-10s\033[0m %s\n", $$1, $$2}'
+
+build: ## Compile the binary to ./bin/speedtest-go-exporter
+	@mkdir -p $(BIN_DIR)
+	CGO_ENABLED=$(CGO_ENABLED) go build -o $(BIN_DIR)/$(BINARY) $(CMD)
+
+test: ## Run all tests
+	go test -v -count=1 ./...
+
+cover: ## Run tests with coverage report
+	go test -cover -coverpkg=./... -coverprofile=coverage.txt -covermode=atomic ./...
+	go tool cover -func=coverage.txt
+
+lint: ## Run golangci-lint if available, otherwise fall back to go vet
+	@if command -v golangci-lint >/dev/null 2>&1; then \
+		golangci-lint run; \
+	else \
+		echo "golangci-lint not found, falling back to go vet"; \
+		go vet ./...; \
+	fi
+
+vet: ## Run go vet
+	go vet ./...
+
+fmt: ## Check formatting (exits non-zero if files need formatting)
+	@test -z "$$(gofmt -l .)" || (gofmt -l . && exit 1)
+
+run: build ## Build and run the exporter (env: SPEEDTEST_PORT, SPEEDTEST_SERVER, SPEEDTEST_EXPORTER_DEBUG)
+	$(BIN_DIR)/$(BINARY)
+
+clean: ## Remove build artifacts (./bin/, coverage.txt)
+	rm -rf $(BIN_DIR) coverage.txt

README.md

@@ -37,7 +37,7 @@ Download the latest release from the [releases page](https://github.com/zakame/s
 ### Building from Source
 
 Requirements:
-- Go 1.25 or later
+- Go 1.26 or later
 
 ```bash
 git clone https://github.com/zakame/speedtest-go-exporter.git
@@ -61,7 +61,7 @@ Configuration is done via environment variables:
 |----------|-------------|---------|
 | `SPEEDTEST_PORT` | Port to listen on | `9798` |
 | `SPEEDTEST_SERVER` | Speedtest server ID to use (optional, auto-selects if not set) | `` |
-| `SPEEDTEST_EXPORTER_DEBUG` | Enable debug mode (adds Go runtime and process metrics) | `false` |
+| `SPEEDTEST_EXPORTER_DEBUG` | Enable debug mode — any non-empty value enables it (adds Go runtime and process metrics) | `` |
 
 ### Example
 
@@ -74,22 +74,48 @@ export SPEEDTEST_EXPORTER_DEBUG=1
 
 ## Metrics
 
-The exporter provides the following Prometheus metrics:
+The exporter provides the following Prometheus metrics. None carry labels.
 
-| Metric | Type | Description |
-|--------|------|-------------|
-| `speedtest_server_id` | Gauge | Speedtest server ID used for the test |
-| `speedtest_jitter_latency_milliseconds` | Gauge | Jitter latency in milliseconds |
-| `speedtest_ping_latency_milliseconds` | Gauge | Ping latency in milliseconds |
-| `speedtest_download_bits_per_second` | Gauge | Download speed in bits per second |
-| `speedtest_upload_bits_per_second` | Gauge | Upload speed in bits per second |
-| `speedtest_up` | Gauge | Speedtest up status (`1` = successful, `0` = failed) |
+| Metric | Type | Unit | Description |
+|--------|------|------|-------------|
+| `speedtest_server_id` | Gauge | — | Numeric ID of the speedtest server used for the test |
+| `speedtest_jitter_latency_milliseconds` | Gauge | milliseconds | Jitter latency |
+| `speedtest_ping_latency_milliseconds` | Gauge | milliseconds | Ping (round-trip) latency |
+| `speedtest_download_bits_per_second` | Gauge | bits/second | Download speed |
+| `speedtest_upload_bits_per_second` | Gauge | bits/second | Upload speed |
+| `speedtest_up` | Gauge | — | `1` if the last speedtest succeeded, `0` if it failed |
+
+### Example output
+
+```
+# HELP speedtest_download_bits_per_second Speedtest download speed in bits per second.
+# TYPE speedtest_download_bits_per_second gauge
+speedtest_download_bits_per_second 9.4e+08
+# HELP speedtest_jitter_latency_milliseconds Speedtest jitter latency in milliseconds.
+# TYPE speedtest_jitter_latency_milliseconds gauge
+speedtest_jitter_latency_milliseconds 0.512
+# HELP speedtest_ping_latency_milliseconds Speedtest ping latency in milliseconds.
+# TYPE speedtest_ping_latency_milliseconds gauge
+speedtest_ping_latency_milliseconds 7.25
+# HELP speedtest_server_id Speedtest server ID.
+# TYPE speedtest_server_id gauge
+speedtest_server_id 12345
+# HELP speedtest_up Speedtest up status.
+# TYPE speedtest_up gauge
+speedtest_up 1
+# HELP speedtest_upload_bits_per_second Speedtest upload speed in bits per second.
+# TYPE speedtest_upload_bits_per_second gauge
+speedtest_upload_bits_per_second 5.2e+08
+```
+
+### Failure behaviour
 
 When a speedtest fails (network error, server unreachable, timeout), `speedtest_up` is set to `0`
 and all other metrics are set to `0`. Use `speedtest_up == 0` as the signal in alerts — the
 zeroed values for speed/latency metrics on failure should be ignored.
 
-When `SPEEDTEST_EXPORTER_DEBUG` is enabled, additional Go runtime metrics are also exposed.
+When `SPEEDTEST_EXPORTER_DEBUG` is set, additional Go runtime metrics (`go_*`) and process
+metrics (`process_*`) from the standard Prometheus Go client collectors are also exposed.
 
 ## Kubernetes Deployment
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/zakame/speedtest-go-exporter
 
-go 1.25
+go 1.26
 
 require (
 	github.com/prometheus/client_golang v1.23.2

internal/exporter/collector.go

@@ -4,6 +4,7 @@ package exporter
 
 import (
 	"context"
+	"errors"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -71,7 +72,21 @@ func (se SpeedtestCollector) Collect(ch chan<- prometheus.Metric) {
 
 	s, err := se.runner.Run(ctx)
 	if err != nil {
-		log.WithError(err).Error("Speedtest failed")
+		if errors.Is(err, context.DeadlineExceeded) {
+			log.WithError(err).Error("Speedtest timed out")
+		} else {
+			log.WithError(err).Error("Speedtest failed")
+		}
+		ch <- prometheus.MustNewConstMetric(server, prometheus.GaugeValue, 0)
+		ch <- prometheus.MustNewConstMetric(jitter, prometheus.GaugeValue, 0)
+		ch <- prometheus.MustNewConstMetric(ping, prometheus.GaugeValue, 0)
+		ch <- prometheus.MustNewConstMetric(downloadSpeed, prometheus.GaugeValue, 0)
+		ch <- prometheus.MustNewConstMetric(uploadSpeed, prometheus.GaugeValue, 0)
+		ch <- prometheus.MustNewConstMetric(up, prometheus.GaugeValue, 0)
+		return
+	}
+	if s == nil {
+		log.Error("Speedtest returned no result")
 		ch <- prometheus.MustNewConstMetric(server, prometheus.GaugeValue, 0)
 		ch <- prometheus.MustNewConstMetric(jitter, prometheus.GaugeValue, 0)
 		ch <- prometheus.MustNewConstMetric(ping, prometheus.GaugeValue, 0)