refactor: combine functions into one file

pkg/system/system.go

@@ -0,0 +1,131 @@
+package system
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+// file to check to determine Operating System
+const etcOsRelease = "/etc/os-release"
+
+// getSysInfo gets sysinfo.
+func getSysInfo() (*syscall.Sysinfo_t, error) {
+	si := &syscall.Sysinfo_t{}
+	err := syscall.Sysinfo(si)
+	if err != nil {
+		return nil, err
+	}
+	return si, nil
+}
+
+// GetTotalMem gets total ram of host.
+func GetTotalMem() (uint64, error) {
+	si, err := getSysInfo()
+	if err != nil {
+		return 0, err
+	}
+	return si.Totalram, nil
+}
+
+// GetDevID returns device id via syscall according to the input directory.
+func GetDevID(dir string) (uint64, error) {
+	var st syscall.Stat_t
+	if err := syscall.Stat(dir, &st); err != nil {
+		return 0, errors.Wrapf(err, "failed to get device id of directory: (%s)", dir)
+	}
+	return st.Dev, nil
+}
+
+// GetSerialNumber gets serial number or a machine.
+func GetSerialNumber() string {
+	var sn string
+	if b, e := exec.Command("dmidecode", "-s", "system-serial-number").CombinedOutput(); e == nil {
+		scanner := bufio.NewScanner(bytes.NewReader(b))
+		for scanner.Scan() {
+			sn = scanner.Text()
+		}
+	}
+	if len(strings.Fields(sn)) != 0 {
+		sn = strings.Fields(sn)[0]
+	}
+	for i := 0; i < 10; i++ {
+		if _, ex := os.Stat("/usr/alisys/dragoon/libexec/armory/bin/armoryinfo"); ex == nil {
+			if b, e := exec.Command("/usr/alisys/dragoon/libexec/armory/bin/armoryinfo", "sn").CombinedOutput(); e == nil {
+				sn = strings.TrimSpace(string(b))
+			}
+		}
+		if sn != "" {
+			break
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+	return sn
+}
+
+// GetNodeIP fetches node ip via command hostname.
+// If it fails to get this, return empty string directly.
+func GetNodeIP() string {
+	output, err := exec.Command("hostname", "-i").CombinedOutput()
+	if err != nil {
+		return ""
+	}
+
+	scanner := bufio.NewScanner(bytes.NewReader(output))
+	for scanner.Scan() {
+		ip := scanner.Text()
+		if net.ParseIP(ip) != nil {
+			return ip
+		}
+	}
+	return ""
+}
+
+// GetOSName gets data in /etc/os-release and gets OS name.
+// For example, in a Ubuntu host, fetched data are like:
+// root@i-8brpbc9t:~# cat /etc/os-release
+// NAME="Ubuntu"
+// VERSION="16.04.2 LTS (Xenial Xerus)"
+// ID=ubuntu
+// ID_LIKE=debian
+// PRETTY_NAME="Ubuntu 16.04.2 LTS"
+// VERSION_ID="16.04"
+// HOME_URL="http://www.ubuntu.com/"
+// SUPPORT_URL="http://help.ubuntu.com/"
+// BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
+// VERSION_CODENAME=xenial
+// UBUNTU_CODENAME=xenial
+func GetOSName() (string, error) {
+	etcOsReleaseFile, err := os.Open(etcOsRelease)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return "", fmt.Errorf("failed to open %s: %v", etcOsRelease, err)
+		}
+	}
+	defer etcOsReleaseFile.Close()
+
+	var prettyName string
+
+	scanner := bufio.NewScanner(etcOsReleaseFile)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if !strings.HasPrefix(line, "PRETTY_NAME=") {
+			continue
+		}
+
+		data := strings.SplitN(line, "=", 2)
+		prettyName = data[1]
+		return prettyName, nil
+	}
+
+	return "Linux", nil
+
+}