Golangci lint fixes (#195)

* Add golangci-lin as make target
* Fix: could omit type ... from declaration; it will be inferred from the right-hand side (staticcheck)
* Fix func intArrayContains is unused (unused)
* Fix: could use strings.ReplaceAll instead (staticcheck)
* Fix: could expand call to math.Pow (staticcheck)
* Fix: could use tagged switch on `...` (staticcheck)
* Fix: Error return value of `...` is not checked (errcheck)
* Fix: ineffectual assignment to err (ineffassign)
* Fix: There is no need to wait for command completion
* Add cpustat, diskstat and schedstat config
* Use slices to exclude metrics
* Replaced stringArrayContains by slices.Contains
* Replace m[k]=v loop with maps.Copy
* Use module slices from the standard library. Remove use of golang.org/x/exp/slices
* Use SplitSeq and max to modernize code

collectors/ipmiMetric.go

@@ -14,7 +14,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"log"
 	"os/exec"
 	"strconv"
 	"strings"
@@ -44,7 +43,9 @@ func (m *IpmiCollector) Init(config json.RawMessage) error {
 	}
 
 	m.name = "IpmiCollector"
-	m.setup()
+	if err := m.setup(); err != nil {
+		return fmt.Errorf("%s Init(): setup() call failed: %w", m.name, err)
+	}
 	m.parallel = true
 	m.meta = map[string]string{
 		"source": m.name,
@@ -116,15 +117,16 @@ func (m *IpmiCollector) readIpmiTool(cmd string, output chan lp.CCMessage) {
 		}
 		v, err := strconv.ParseFloat(strings.TrimSpace(lv[1]), 64)
 		if err == nil {
-			name := strings.ToLower(strings.Replace(strings.TrimSpace(lv[0]), " ", "_", -1))
+			name := strings.ToLower(strings.ReplaceAll(strings.TrimSpace(lv[0]), " ", "_"))
 			unit := strings.TrimSpace(lv[2])
-			if unit == "Volts" {
+			switch unit {
+			case "Volts":
 				unit = "Volts"
-			} else if unit == "degrees C" {
+			case "degrees C":
 				unit = "degC"
-			} else if unit == "degrees F" {
+			case "degrees F":
 				unit = "degF"
-			} else if unit == "Watts" {
+			case "Watts":
 				unit = "Watts"
 			}
 
@@ -150,22 +152,29 @@ func (m *IpmiCollector) readIpmiTool(cmd string, output chan lp.CCMessage) {
 
 func (m *IpmiCollector) readIpmiSensors(cmd string, output chan lp.CCMessage) {
 
+	// Setup ipmisensors command
 	command := exec.Command(cmd, "--comma-separated-output", "--sdr-cache-recreate")
-	command.Wait()
-	stdout, err := command.Output()
-	if err != nil {
-		log.Print(err)
+	stdout, _ := command.StdoutPipe()
+	errBuf := new(bytes.Buffer)
+	command.Stderr = errBuf
+
+	// start command
+	if err := command.Start(); err != nil {
+		cclog.ComponentError(
+			m.name,
+			fmt.Sprintf("readIpmiSensors(): Failed to start command \"%s\": %v", command.String(), err),
+		)
 		return
 	}
 
-	ll := strings.Split(string(stdout), "\n")
-
-	for _, line := range ll {
-		lv := strings.Split(line, ",")
+	// Read command output
+	scanner := bufio.NewScanner(stdout)
+	for scanner.Scan() {
+		lv := strings.Split(scanner.Text(), ",")
 		if len(lv) > 3 {
 			v, err := strconv.ParseFloat(lv[3], 64)
 			if err == nil {
-				name := strings.ToLower(strings.Replace(lv[1], " ", "_", -1))
+				name := strings.ToLower(strings.ReplaceAll(lv[1], " ", "_"))
 				y, err := lp.NewMessage(name, map[string]string{"type": "node"}, m.meta, map[string]interface{}{"value": v}, time.Now())
 				if err == nil {
 					if len(lv) > 4 {
@@ -176,6 +185,18 @@ func (m *IpmiCollector) readIpmiSensors(cmd string, output chan lp.CCMessage) {
 			}
 		}
 	}
+
+	// Wait for command end
+	if err := command.Wait(); err != nil {
+		errMsg, _ := io.ReadAll(errBuf)
+		cclog.ComponentError(
+			m.name,
+			fmt.Sprintf("readIpmiSensors(): Failed to wait for the end of command \"%s\": %v\n", command.String(), err),
+		)
+		cclog.ComponentError(m.name, fmt.Sprintf("readIpmiSensors(): command stderr: \"%s\"\n", strings.TrimSpace(string(errMsg))))
+		return
+	}
+
 }
 
 func (m *IpmiCollector) Read(interval time.Duration, output chan lp.CCMessage) {