[host]: add not implemented methods.

Makefile

@@ -20,7 +20,7 @@ build_test:  ## test only buildable
 	CGO_ENABLED=1 GOOS=darwin go test ./... | $(BUILD_FAIL_PATTERN)
 	GOOS=windows go test ./... | $(BUILD_FAIL_PATTERN)
 	# Operating systems supported for building only (not implemented error if used)
-	GOOS=dragonfly go test ./... | $(BUILD_FAIL_PATTERN)
-	GOOS=netbsd go test ./... | $(BUILD_FAIL_PATTERN)
 	GOOS=solaris go test ./... | $(BUILD_FAIL_PATTERN)
+#	GOOS=dragonfly go test ./... | $(BUILD_FAIL_PATTERN)
+	GOOS=netbsd go test ./... | $(BUILD_FAIL_PATTERN)
 	@echo 'Successfully built on all known operating systems'

disk/disk_fallback.go

@@ -1,4 +1,4 @@
-// +build !darwin,!linux,!freebsd,!openbsd,!windows
+// +build !darwin,!linux,!freebsd,!openbsd,!windows,!solaris
 
 package disk
 

host/host_darwin.go

@@ -181,8 +181,10 @@ func PlatformInformation() (string, string, string, error) {
 }
 
 func Virtualization() (string, string, error) {
-	system := ""
-	role := ""
+	return "", "", common.ErrNotImplementedError
+}
 
-	return system, role, nil
+func KernelVersion() (string, error) {
+	_, _, version, err := PlatformInformation()
+	return version, err
 }

host/host_fallback.go

@@ -19,3 +19,11 @@ func Uptime() (uint64, error) {
 func Users() ([]UserStat, error) {
 	return []UserStat{}, common.ErrNotImplementedError
 }
+
+func Virtualization() (string, string, error) {
+	return "", "", common.ErrNotImplementedError
+}
+
+func KernelVersion() (string, error) {
+	return "", common.ErrNotImplementedError
+}

host/host_freebsd.go

@@ -174,10 +174,7 @@ func PlatformInformation() (string, string, string, error) {
 }
 
 func Virtualization() (string, string, error) {
-	system := ""
-	role := ""
-
-	return system, role, nil
+	return "", "", common.ErrNotImplementedError
 }
 
 // before 9.0
@@ -222,3 +219,8 @@ func getUsersFromUtmp(utmpfile string) ([]UserStat, error) {
 func SensorsTemperatures() ([]TemperatureStat, error) {
 	return []TemperatureStat{}, common.ErrNotImplementedError
 }
+
+func KernelVersion() (string, error) {
+	_, _, version, err := PlatformInformation()
+	return version, err
+}

host/host_openbsd.go

@@ -110,10 +110,7 @@ func PlatformInformation() (string, string, string, error) {
 }
 
 func Virtualization() (string, string, error) {
-	system := ""
-	role := ""
-
-	return system, role, nil
+	return "", "", common.ErrNotImplementedError
 }
 
 func Users() ([]UserStat, error) {
@@ -158,3 +155,8 @@ func Users() ([]UserStat, error) {
 func SensorsTemperatures() ([]TemperatureStat, error) {
 	return []TemperatureStat{}, common.ErrNotImplementedError
 }
+
+func KernelVersion() (string, error) {
+	_, _, version, err := PlatformInformation()
+	return version, err
+}

host/host_solaris.go

@@ -179,3 +179,26 @@ func Users() ([]UserStat, error) {
 func SensorsTemperatures() ([]TemperatureStat, error) {
 	return []TemperatureStat{}, common.ErrNotImplementedError
 }
+
+func Virtualization() (string, string, error) {
+	return "", "", common.ErrNotImplementedError
+}
+
+func KernelVersion() (string, error) {
+	// Parse versions from output of `uname(1)`
+	uname, err := exec.LookPath("/usr/bin/uname")
+	if err != nil {
+		return "", err
+	}
+
+	out, err := invoke.Command(uname, "-srv")
+	if err != nil {
+		return "", err
+	}
+
+	fields := strings.Fields(string(out))
+	if len(fields) >= 2 {
+		return fields[1], nil
+	}
+	return "", fmt.Errorf("could not get kernel version")
+}

host/host_test.go

@@ -126,3 +126,15 @@ func TestVirtualization(t *testing.T) {
 
 	t.Logf("Virtualization(): %s, %s", system, role)
 }
+
+func TestKernelVersion(t *testing.T) {
+	version, err := KernelVersion()
+	if err != nil {
+		t.Errorf("KernelVersion() failed, %v", err)
+	}
+	if version == "" {
+		t.Errorf("KernelVersion() retuns empty: %s", version)
+	}
+
+	t.Logf("KernelVersion(): %s", version)
+}

host/host_windows.go

@@ -192,3 +192,8 @@ func SensorsTemperatures() ([]TemperatureStat, error) {
 func Virtualization() (string, string, error) {
 	return "", "", common.ErrNotImplementedError
 }
+
+func KernelVersion() (string, error) {
+	_, _, version, err := PlatformInformation()
+	return version, err
+}