introduce basic fact collection

client/vendor/github.com/zcalusic/sysinfo/storage.go

@@ -0,0 +1,104 @@
+// Copyright © 2016 Zlatko Čalušić
+//
+// Use of this source code is governed by an MIT-style license that can be found in the LICENSE file.
+
+package sysinfo
+
+import (
+	"bufio"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+)
+
+// StorageDevice information.
+type StorageDevice struct {
+	Name   string `json:"name,omitempty"`
+	Driver string `json:"driver,omitempty"`
+	Vendor string `json:"vendor,omitempty"`
+	Model  string `json:"model,omitempty"`
+	Serial string `json:"serial,omitempty"`
+	Size   uint   `json:"size,omitempty"` // device size in GB
+}
+
+func getSerial(name, fullpath string) (serial string) {
+	var f *os.File
+	var err error
+
+	// Modern location/format of the udev database.
+	if dev := slurpFile(path.Join(fullpath, "dev")); dev != "" {
+		if f, err = os.Open(path.Join("/run/udev/data", "b"+dev)); err == nil {
+			goto scan
+		}
+	}
+
+	// Legacy location/format of the udev database.
+	if f, err = os.Open(path.Join("/dev/.udev/db", "block:"+name)); err == nil {
+		goto scan
+	}
+
+	// No serial :(
+	return
+
+scan:
+	defer f.Close()
+
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		if sl := strings.Split(s.Text(), "="); len(sl) == 2 {
+			if sl[0] == "E:ID_SERIAL_SHORT" {
+				serial = sl[1]
+				break
+			}
+		}
+	}
+
+	return
+}
+
+func (si *SysInfo) getStorageInfo() {
+	sysBlock := "/sys/block"
+	devices, err := os.ReadDir(sysBlock)
+	if err != nil {
+		return
+	}
+
+	si.Storage = make([]StorageDevice, 0)
+	for _, link := range devices {
+		fullpath := path.Join(sysBlock, link.Name())
+		dev, err := os.Readlink(fullpath)
+		if err != nil {
+			continue
+		}
+
+		if strings.HasPrefix(dev, "../devices/virtual/") {
+			continue
+		}
+
+		// We could filter all removable devices here, but some systems boot from USB flash disks, and then we
+		// would filter them, too. So, let's filter only floppies and CD/DVD devices, and see how it pans out.
+		if strings.HasPrefix(dev, "../devices/platform/floppy") || slurpFile(path.Join(fullpath, "device", "type")) == "5" {
+			continue
+		}
+
+		device := StorageDevice{
+			Name:   link.Name(),
+			Model:  slurpFile(path.Join(fullpath, "device", "model")),
+			Serial: getSerial(link.Name(), fullpath),
+		}
+
+		if driver, err := os.Readlink(path.Join(fullpath, "device", "driver")); err == nil {
+			device.Driver = path.Base(driver)
+		}
+
+		if vendor := slurpFile(path.Join(fullpath, "device", "vendor")); !strings.HasPrefix(vendor, "0x") {
+			device.Vendor = vendor
+		}
+
+		size, _ := strconv.ParseUint(slurpFile(path.Join(fullpath, "size")), 10, 64)
+		device.Size = uint(size) / 1953125 // GiB
+
+		si.Storage = append(si.Storage, device)
+	}
+}