Add context to errors. Remove unnecessary code

plugins/inputs/irqstat/irqstat.go

@@ -10,9 +10,7 @@ import (
 	"strings"
 )
 
-type Irqstat struct {
-	Include []string
-}
+type Irqstat struct{}
 
 type IRQ struct {
 	ID     string
@@ -26,9 +24,10 @@ func NewIRQ(id string) *IRQ {
 }
 
 const sampleConfig = `
-  ## A list of IRQs to include for metric ingestion, if not specified
-  ## will default to collecting all IRQs.
-  # include = ["0", "1", "30", "NET_RX"]
+  ## To filter which IRQs to collect
+  ## make use of tagpass / tagdrop, i.e.
+  # [inputs.irqstat.tagdrop]
+    # irq = [ "NET_RX", "TASKLET" ]
 `
 
 func (s *Irqstat) Description() string {
@@ -39,8 +38,7 @@ func (s *Irqstat) SampleConfig() string {
 	return sampleConfig
 }
 
-func parseInterrupts(irqdata string, include []string) ([]IRQ, error) {
-	var err error
+func parseInterrupts(irqdata string) ([]IRQ, error) {
 	var irqs []IRQ
 	var cpucount int
 	scanner := bufio.NewScanner(strings.NewReader(irqdata))
@@ -69,7 +67,7 @@ func parseInterrupts(irqdata string, include []string) ([]IRQ, error) {
 			if i < len(fields) {
 				irqval, err = strconv.ParseInt(fields[i], 10, 64)
 				if err != nil {
-					return irqs, err
+					return irqs, fmt.Errorf("Unable to parse %q from %q: %s", fields[i], scanner.Text(), err)
 				}
 				irq.Values[cpu] = irqval
 			}
@@ -78,33 +76,24 @@ func parseInterrupts(irqdata string, include []string) ([]IRQ, error) {
 		irq.Type = irqtype
 		irq.Device = irqdevice
 		irq.Values["total"] = irqtotal
-		if len(include) == 0 || stringInSlice(irq.ID, include) {
-			irqs = append(irqs, *irq)
-		}
-	}
-	return irqs, err
-}
-
-func stringInSlice(x string, list []string) bool {
-	for _, y := range list {
-		if y == x {
-			return true
-		}
+		irqs = append(irqs, *irq)
 	}
-	return false
+	return irqs, nil
 }
 
 func (s *Irqstat) Gather(acc telegraf.Accumulator) error {
 	files := []string{"/proc/interrupts", "/proc/softirqs"}
 	for _, file := range files {
 		data, err := ioutil.ReadFile(file)
 		if err != nil {
-			acc.AddError(err)
+			acc.AddError(fmt.Errorf("Reading %s: %s", file, err))
+			continue
 		}
 		irqdata := string(data)
-		irqs, err := parseInterrupts(irqdata, s.Include)
+		irqs, err := parseInterrupts(irqdata)
 		if err != nil {
-			acc.AddError(err)
+			acc.AddError(fmt.Errorf("Parsing %s: %s", file, err))
+			continue
 		}
 		for _, irq := range irqs {
 			tags := map[string]string{"irq": irq.ID, "type": irq.Type, "device": irq.Device}

plugins/inputs/irqstat/irqstat_test.go

@@ -7,7 +7,6 @@ import (
 )
 
 func TestParseInterrupts(t *testing.T) {
-	include := []string{}
 	interruptStr := `           CPU0       CPU1       
   0:        134          0   IO-APIC-edge      timer
   1:          7          3   IO-APIC-edge      i8042
@@ -26,7 +25,7 @@ TASKLET:	205			0`
 		IRQ{ID: "NET_RX", Values: map[string]interface{}{"CPU0": int64(867028), "CPU1": int64(225), "total": int64(867253)}},
 		IRQ{ID: "TASKLET", Values: map[string]interface{}{"CPU0": int64(205), "CPU1": int64(0), "total": int64(205)}},
 	}
-	got, err := parseInterrupts(interruptStr, include)
+	got, err := parseInterrupts(interruptStr)
 	require.Equal(t, nil, err)
 	require.NotEqual(t, 0, len(got))
 	require.Equal(t, len(got), len(parsed))