linux and windows done

providers/linux/host_linux.go

@@ -18,11 +18,14 @@
 package linux
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"github.com/joeshaw/multierror"
@@ -138,7 +141,7 @@ func (h *host) CPUTime() (types.CPUTimes, error) {
 }
 
 func newHost(fs procFS) (*host, error) {
-	stat, err := fs.NewStat()
+	stat, err := fs.Stat()
 	if err != nil {
 		return nil, fmt.Errorf("failed to read proc stat: %w", err)
 	}
@@ -149,11 +152,13 @@ func newHost(fs procFS) (*host, error) {
 	r.bootTime(h)
 	r.containerized(h)
 	r.hostname(h)
+	r.fqdn(h)
 	r.network(h)
 	r.kernelVersion(h)
 	r.os(h)
 	r.time(h)
 	r.uniqueID(h)
+
 	return h, r.Err()
 }
 
@@ -210,6 +215,24 @@ func (r *reader) hostname(h *host) {
 	h.info.Hostname = v
 }
 
+func (r *reader) fqdn(h *host) {
+	const cmdPath, args = "/bin/hostname", "-f"
+	cmd := exec.Command(cmdPath, args)
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+	if err != nil {
+		r.addErr(fmt.Errorf("could not get linux FQDN:'%s %s' failed to run: %q: %w",
+			cmdPath, args, strings.Trim(stderr.String(), "\n"), err))
+		return
+	}
+
+	h.info.FQDN = strings.Trim(stdout.String(), "\n")
+}
+
 func (r *reader) network(h *host) {
 	ips, macs, err := shared.Network()
 	if r.addErr(err) {

providers/windows/host_windows.go

@@ -19,15 +19,18 @@ package windows
 
 import (
 	"errors"
+	"fmt"
 	"os"
+	"syscall"
 	"time"
 
-	windows "github.com/elastic/go-windows"
 	"github.com/joeshaw/multierror"
+	stdwindows "golang.org/x/sys/windows"
 
 	"github.com/elastic/go-sysinfo/internal/registry"
 	"github.com/elastic/go-sysinfo/providers/shared"
 	"github.com/elastic/go-sysinfo/types"
+	"github.com/elastic/go-windows"
 )
 
 func init() {
@@ -137,6 +140,39 @@ func (r *reader) hostname(h *host) {
 	h.info.Hostname = v
 }
 
+func (r *reader) fqdn(h *host) {
+	size := uint32(64)
+	for {
+		buff := make([]uint16, size)
+		err := stdwindows.GetComputerNameEx(
+			stdwindows.ComputerNamePhysicalDnsFullyQualified, &buff[0], &size)
+		if err == nil {
+			h.info.FQDN = syscall.UTF16ToString(buff[:size])
+			return
+		}
+
+		// ERROR_MORE_DATA means buff is too small and size is set to the
+		// number of bytes needed to store the FQDN. For details, see
+		// https://learn.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getcomputernameexw#return-value
+		if errors.Is(err, syscall.ERROR_MORE_DATA) {
+			if size <= uint32(len(buff)) {
+				// Safeguard to avoid an infinite loop.
+				r.addErr(fmt.Errorf(
+					"windows.GetComputerNameEx returned ERROR_MORE_DATA, " +
+						"but data size should fit into buffer"))
+				return
+			} else {
+				// Grow the buffer and try again.
+				// Should we limit its growth?
+				buff = make([]uint16, size)
+				continue
+			}
+		}
+
+		r.addErr(fmt.Errorf("could not get windows FQDN: could not get windows.ComputerNamePhysicalDnsFullyQualified: %w", err))
+	}
+}
+
 func (r *reader) network(h *host) {
 	ips, macs, err := shared.Network()
 	if r.addErr(err) {

providers/windows/host_windows_test.go

@@ -0,0 +1,21 @@
+package windows
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/elastic/go-sysinfo/internal/registry"
+)
+
+var _ registry.HostProvider = windowsSystem{}
+
+func TestHost(t *testing.T) {
+	host, err := windowsSystem{}.Host()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	info := host.Info()
+	data, _ := json.MarshalIndent(info, "", "  ")
+	t.Log(string(data))
+}

types/host.go

@@ -67,6 +67,7 @@ type HostInfo struct {
 	BootTime          time.Time `json:"boot_time"`               // Host boot time.
 	Containerized     *bool     `json:"containerized,omitempty"` // Is the process containerized.
 	Hostname          string    `json:"name"`                    // Hostname
+	FQDN              string    `json:"fqdn"`                    // FQDN
 	IPs               []string  `json:"ip,omitempty"`            // List of all IPs.
 	KernelVersion     string    `json:"kernel_version"`          // Kernel version.
 	MACs              []string  `json:"mac"`                     // List of MAC addresses.