Merge pull request coreos#354 from hudeng-go/master-new

sdjournal: add GetBootID support

Author: Luca Bruno

sdjournal/journal.go

@@ -300,6 +300,24 @@ package sdjournal
 //   return sd_journal_get_catalog(j, ret);
 // }
 //
+// int
+// my_sd_id128_get_boot(void *f, sd_id128_t *boot_id)
+// {
+//   int(*sd_id128_get_boot)(sd_id128_t *);
+//
+//   sd_id128_get_boot = f;
+//   return sd_id128_get_boot(boot_id);
+// }
+//
+// char *
+// my_sd_id128_to_string(void *f, sd_id128_t boot_id, char s[_SD_ARRAY_STATIC SD_ID128_STRING_MAX])
+// {
+//   char *(*sd_id128_to_string)(sd_id128_t, char *);
+//
+//   sd_id128_to_string = f;
+//   return sd_id128_to_string(boot_id, s);
+// }
+//
 import "C"
 import (
 	"bytes"
@@ -1118,3 +1136,33 @@ func (j *Journal) GetCatalog() (string, error) {
 
 	return catalog, nil
 }
+
+// GetBootID get systemd boot id
+func (j *Journal) GetBootID() (string, error) {
+	sd_id128_get_boot, err := getFunction("sd_id128_get_boot")
+	if err != nil {
+		return "", err
+	}
+
+	var boot_id C.sd_id128_t
+	r := C.my_sd_id128_get_boot(sd_id128_get_boot, &boot_id)
+	if r < 0 {
+		return "", fmt.Errorf("failed to get boot id: %s", syscall.Errno(-r).Error())
+	}
+
+	sd_id128_to_string, err := getFunction("sd_id128_to_string")
+	if err != nil {
+		return "", err
+	}
+
+	c := (*C.char)(C.malloc(33))
+	defer C.free(unsafe.Pointer(c))
+	C.my_sd_id128_to_string(sd_id128_to_string, boot_id, c)
+
+	bootID := C.GoString(c)
+	if len(bootID) <= 0 {
+		return "", fmt.Errorf("get boot id %s is not valid", bootID)
+	}
+
+	return bootID, nil
+}

sdjournal/journal_test.go

@@ -470,6 +470,27 @@ func TestJournalGetCatalog(t *testing.T) {
 	}
 }
 
+func TestJournalGetBootID(t *testing.T) {
+	j, err := NewJournal()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	defer j.Close()
+
+	bootID, err := j.GetBootID()
+
+	if err != nil {
+		t.Fatalf("Failed to get bootID : %s", err)
+	}
+
+	if len(bootID) <= 0 {
+		t.Fatalf("Get bootID: %s is Null", bootID)
+	}
+
+	fmt.Printf("Test GetBootID: %s", bootID)
+}
+
 func contains(s []string, v string) bool {
 	for _, entry := range s {
 		if entry == v {