Fixed #5

cmd/sd-dbus-hooks/start.go

@@ -49,7 +49,8 @@ func (h unitStartHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 func start(conn *dbus.Conn, cfg *Config, u Unit, ch chan<- string) error {
 	// check if unit active
-	units, err := conn.ListUnitsByPatterns([]string{"active"}, []string{u.Name})
+	// units, err := conn.ListUnitsByPatterns([]string{"active"}, []string{u.Name})
+	units, err := listUnitsByPatterns(conn, []string{"active"}, []string{u.Name})
 	if err != nil {
 		return err
 	}
@@ -60,7 +61,8 @@ func start(conn *dbus.Conn, cfg *Config, u Unit, ch chan<- string) error {
 
 	if len(u.BlockedBy) > 0 {
 		// check if unit blocked by other active unit
-		blockUnits, err := conn.ListUnitsByPatterns([]string{"active"}, u.BlockedBy)
+		// blockUnits, err := conn.ListUnitsByPatterns([]string{"active"}, u.BlockedBy)
+		blockUnits, err := listUnitsByPatterns(conn, []string{"active"}, u.BlockedBy)
 		if err != nil {
 			return err
 		}

cmd/sd-dbus-hooks/status.go

@@ -34,7 +34,11 @@ func (h unitStatusHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	} else {
 		matchFilter = []string{name}
 	}
-	units, unitsErr := h.conn.ListUnitsByPatterns([]string{"active", "inactive", "failed"}, matchFilter)
+
+	// ListUnitsByPatterns is not available on systemd-219 (centos7)
+	//units, unitsErr := h.conn.ListUnitsByPatterns([]string{"active", "inactive", "failed"}, matchFilter)
+
+	units, unitsErr := listUnitsByPatterns(h.conn, []string{"active", "inactive", "failed"}, matchFilter)
 	if unitsErr != nil {
 		log.Printf("[ERROR] %s", unitsErr)
 		http.Error(w, unitsErr.Error(), http.StatusInternalServerError)

cmd/sd-dbus-hooks/utils.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"errors"
+	"log"
+	"path"
+
+	"github.com/coreos/go-systemd/dbus"
+)
+
+func listUnitsByPatterns(conn *dbus.Conn, states []string, patterns []string) ([]dbus.UnitStatus, error) {
+	var result []dbus.UnitStatus
+
+	units, err := conn.ListUnits()
+	if err != nil {
+		return nil, err
+	}
+
+	for _, unit := range units {
+		if contains(patterns, unit.Name) && contains(states, unit.ActiveState) {
+			result = append(result, unit)
+			continue
+		}
+	}
+
+	// systemd can doesn't show all loaded units in some cases (if there's no reason to keep it in memory)
+	// https://github.com/systemd/systemd/issues/5063
+	//
+	// so, list all units files for matched names and add it to results
+	unitFiles, err := conn.ListUnitFiles()
+	if err != nil {
+		return nil, err
+	}
+
+UNIT_FILES_LOOP:
+	for _, unitFile := range unitFiles {
+		name := path.Base(unitFile.Path)
+		// skip unit file if result already exist
+		for _, v := range result {
+			if name == v.Name {
+				log.Printf("[DEBUG] unit %v already in results", v.Name)
+				continue UNIT_FILES_LOOP
+			}
+		}
+		if contains(patterns, name) {
+			us := dbus.UnitStatus{
+				Name:        name,
+				Description: "",
+				LoadState:   "not in memory",
+				ActiveState: "not in memory",
+				SubState:    unitFile.Type,
+			}
+			result = append(result, us)
+			continue
+		}
+	}
+
+	if len(result) == 0 {
+		return result, errors.New("units not found")
+	}
+
+	return result, nil
+}
+
+// return true if string `v` contains in slice `s`
+func contains(s []string, v string) bool {
+	for _, i := range s {
+		if i == v {
+			return true
+		}
+	}
+
+	return false
+}

cmd/sd-dbus-hooks/utils_test.go

@@ -0,0 +1,14 @@
+package main
+
+import "testing"
+
+func TestUtils(t *testing.T) {
+	items := []string{"one", "two", "three"}
+	if !contains(items, "one") {
+		t.Errorf("contains: got false, expected true")
+	}
+
+	if contains(items, "four") {
+		t.Errorf("contains: got true, expected false")
+	}
+}