Supplement non-CPU sensor output with identified sysfs temperature

When lm-sensors returns disk or other readings without a CPU chip, retain those readings and add a bounded, identified SoC temperature from sysfs. Preserve existing CPU output and ignore unusable optional sysfs data. Cover combined and precedence paths for Pulse #2311.

Change-source: pulse-maintainer

internal/sensors/collector.go

@@ -2,6 +2,7 @@ package sensors
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -26,9 +27,9 @@ var (
 	hwmonRoot                = "/sys/class/hwmon"
 )
 
-// CollectLocal reads lm-sensors JSON, or a recognised CPU thermal sysfs source
-// when lm-sensors is unavailable or returns no data. A valid lm-sensors result
-// is kept intact so drive, GPU and fan readings are not lost.
+// CollectLocal reads lm-sensors JSON and supplements it with a recognised CPU
+// thermal sysfs source when it contains no CPU chip. Other lm-sensors readings
+// are retained; sysfs is also used when lm-sensors is unavailable or empty.
 func CollectLocal(ctx context.Context) (string, error) {
 	ctx = normalizeCollectionContext(ctx)
 
@@ -47,7 +48,7 @@ func CollectLocal(ctx context.Context) (string, error) {
 		}
 		outputStr := strings.TrimSpace(string(output))
 		if outputStr != "" && outputStr != "{}" {
-			return outputStr, nil
+			return addMissingSysfsCPU(ctx, outputStr), nil
 		}
 		if cmdCtx.Err() != nil {
 			return "", fmt.Errorf("failed to execute sensors: %w", cmdCtx.Err())
@@ -67,6 +68,37 @@ func CollectLocal(ctx context.Context) (string, error) {
 	return "", fmt.Errorf("sensors returned empty output and CPU thermal fallback failed: %w", fallbackErr)
 }
 
+// addMissingSysfsCPU leaves existing output unchanged unless it is a JSON
+// object without a recognised CPU chip and an identified sysfs source is
+// available. A failed optional lookup must not discard working sensors data.
+func addMissingSysfsCPU(ctx context.Context, sensorsJSON string) string {
+	var chips map[string]json.RawMessage
+	if err := json.Unmarshal([]byte(sensorsJSON), &chips); err != nil || chips == nil {
+		return sensorsJSON
+	}
+	for name := range chips {
+		if isCPUChip(strings.ToLower(name)) {
+			return sensorsJSON
+		}
+	}
+	fallbackJSON, err := collectSysfsCPUTemperature(ctx)
+	if err != nil {
+		return sensorsJSON
+	}
+	var fallback map[string]json.RawMessage
+	if err := json.Unmarshal([]byte(fallbackJSON), &fallback); err != nil {
+		return sensorsJSON
+	}
+	for name, value := range fallback {
+		chips[name] = value
+	}
+	merged, err := json.Marshal(chips)
+	if err != nil || len(merged) > maxSensorsOutputSizeBytes {
+		return sensorsJSON
+	}
+	return string(merged)
+}
+
 // collectSysfsCPUTemperature deliberately accepts only identified CPU/SoC
 // sensors. thermal_zone0 is not necessarily a CPU on every Linux machine.
 func collectSysfsCPUTemperature(ctx context.Context) (string, error) {

internal/sensors/collector_additional_test.go

@@ -82,7 +82,7 @@ func TestCollectLocal_SysfsContinuesPastBadSource(t *testing.T) {
 	}
 }
 
-func TestCollectLocal_SensorsJSONPrecedesSysfs(t *testing.T) {
+func TestCollectLocal_SensorsJSONGainsMissingSysfsCPU(t *testing.T) {
 	dir := t.TempDir()
 	writeScript(t, dir, "sensors", "#!/bin/sh\necho '{\"nvme-pci-0100\":{\"Composite\":{\"temp1_input\":39}}}'\n")
 	t.Setenv("PATH", dir+":"+os.Getenv("PATH"))
@@ -92,8 +92,44 @@ func TestCollectLocal_SensorsJSONPrecedesSysfs(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if !strings.Contains(out, "nvme-pci-0100") || strings.Contains(out, "cpu_thermal") {
-		t.Fatalf("lm-sensors result was replaced: %s", out)
+	parsed, err := Parse(out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if parsed.CPUPackage != 57 || parsed.NVMe["nvme0"] != 39 {
+		t.Fatalf("lm-sensors data and sysfs CPU were not combined: %+v", parsed)
+	}
+}
+
+func TestCollectLocal_ExistingCPUPrecedesSysfs(t *testing.T) {
+	dir := t.TempDir()
+	const original = `{"coretemp-isa-0000":{"Package id 0":{"temp1_input":42}}}`
+	writeScript(t, dir, "sensors", "#!/bin/sh\necho '"+original+"'\n")
+	t.Setenv("PATH", dir+":"+os.Getenv("PATH"))
+	thermal, _ := useTestSysfsRoots(t)
+	writeSysfsSensor(t, thermal, "thermal_zone0", "type", "armada_thermal", "57000")
+	out, err := CollectLocal(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out != original {
+		t.Fatalf("existing CPU reading was changed: %s", out)
+	}
+}
+
+func TestCollectLocal_InvalidSysfsDoesNotDiscardOtherSensors(t *testing.T) {
+	dir := t.TempDir()
+	const original = `{"nvme-pci-0100":{"Composite":{"temp1_input":39}}}`
+	writeScript(t, dir, "sensors", "#!/bin/sh\necho '"+original+"'\n")
+	t.Setenv("PATH", dir+":"+os.Getenv("PATH"))
+	thermal, _ := useTestSysfsRoots(t)
+	writeSysfsSensor(t, thermal, "thermal_zone0", "type", "armada_thermal", "bad")
+	out, err := CollectLocal(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out != original {
+		t.Fatalf("valid lm-sensors data was discarded: %s", out)
 	}
 }