Add getServiceFiles function.

The CIS benchmark check for node checks 2 config files for kubelet:
  - kubelet config file (kubelet.conf)
  - kubelet systemd unitfile (10-kubeadm.conf)

The getServiceFiles function gets candidates for kubelet systemd
unitfile and returns valid untifiles.

cmd/common.go

@@ -79,11 +79,13 @@ func runChecks(nodetype check.NodeType) {
 	typeConf = viper.Sub(string(nodetype))
 	binmap := getBinaries(typeConf)
 	confmap := getConfigFiles(typeConf)
+	svcmap := getServiceFiles(typeConf)
 
 	// Variable substitutions. Replace all occurrences of variables in controls files.
 	s := string(in)
 	s = makeSubstitutions(s, "bin", binmap)
 	s = makeSubstitutions(s, "conf", confmap)
+	s = makeSubstitutions(s, "svc", svcmap)
 
 	controls, err := check.NewControls(nodetype, []byte(s))
 	if err != nil {

cmd/util.go

@@ -172,8 +172,6 @@ func decrementVersion(version string) string {
 }
 
 // getConfigFiles finds which of the set of candidate config files exist
-// accepts a string 't' which indicates the type of config file, conf,
-// podspec or untifile.
 func getConfigFiles(v *viper.Viper) map[string]string {
 	confmap := make(map[string]string)
 
@@ -204,6 +202,37 @@ func getConfigFiles(v *viper.Viper) map[string]string {
 	return confmap
 }
 
+// getServiceFiles finds which of the set of candidate service files exist
+func getServiceFiles(v *viper.Viper) map[string]string {
+	svcmap := make(map[string]string)
+
+	for _, component := range v.GetStringSlice("components") {
+		s := v.Sub(component)
+		if s == nil {
+			continue
+		}
+
+		// See if any of the candidate config files exist
+		svc := findConfigFile(s.GetStringSlice("svc"))
+		if svc == "" {
+			if s.IsSet("defaultsvc") {
+				svc = s.GetString("defaultsvc")
+				glog.V(2).Info(fmt.Sprintf("Using default service file name '%s' for component %s", svc, component))
+			} else {
+				// Default the service file name that we'll substitute to the name of the component
+				glog.V(2).Info(fmt.Sprintf("Missing service file for %s", component))
+				svc = component
+			}
+		} else {
+			glog.V(2).Info(fmt.Sprintf("Component %s uses service file '%s'", component, svc))
+		}
+
+		svcmap[component] = svc
+	}
+
+	return svcmap
+}
+
 // verifyBin checks that the binary specified is running
 func verifyBin(bin string) bool {
 

cmd/util_test.go

@@ -289,6 +289,81 @@ func TestGetConfigFiles(t *testing.T) {
 	}
 }
 
+func TestGetServiceFiles(t *testing.T) {
+	cases := []struct {
+		config      map[string]interface{}
+		exp         map[string]string
+		statResults []error
+	}{
+		{
+			config: map[string]interface{}{
+				"components": []string{"kubelet"},
+				"kubelet":    map[string]interface{}{"svc": []string{"kubelet", "10-kubeadm.conf"}},
+			},
+			statResults: []error{os.ErrNotExist, nil},
+			exp:         map[string]string{"kubelet": "10-kubeadm.conf"},
+		},
+		{
+			// Component "thing" isn't included in the list of components
+			config: map[string]interface{}{
+				"components": []string{"kubelet"},
+				"kubelet":    map[string]interface{}{"svc": []string{"kubelet", "10-kubeadm.conf"}},
+				"thing":      map[string]interface{}{"svc": []string{"/my/file/thing"}},
+			},
+			statResults: []error{os.ErrNotExist, nil},
+			exp:         map[string]string{"kubelet": "10-kubeadm.conf"},
+		},
+		{
+			// More than one component
+			config: map[string]interface{}{
+				"components": []string{"kubelet", "thing"},
+				"kubelet":    map[string]interface{}{"svc": []string{"kubelet", "10-kubeadm.conf"}},
+				"thing":      map[string]interface{}{"svc": []string{"/my/file/thing"}},
+			},
+			statResults: []error{os.ErrNotExist, nil, nil},
+			exp:         map[string]string{"kubelet": "10-kubeadm.conf", "thing": "/my/file/thing"},
+		},
+		{
+			// Default thing to specified default service
+			config: map[string]interface{}{
+				"components": []string{"kubelet", "thing"},
+				"kubelet":    map[string]interface{}{"svc": []string{"kubelet", "10-kubeadm.conf"}},
+				"thing":      map[string]interface{}{"svc": []string{"/my/file/thing"}, "defaultsvc": "another/thing"},
+			},
+			statResults: []error{os.ErrNotExist, nil, os.ErrNotExist},
+			exp:         map[string]string{"kubelet": "10-kubeadm.conf", "thing": "another/thing"},
+		},
+		{
+			// Default thing to component name
+			config: map[string]interface{}{
+				"components": []string{"kubelet", "thing"},
+				"kubelet":    map[string]interface{}{"svc": []string{"kubelet", "10-kubeadm.conf"}},
+				"thing":      map[string]interface{}{"svc": []string{"/my/file/thing"}},
+			},
+			statResults: []error{os.ErrNotExist, nil, os.ErrNotExist},
+			exp:         map[string]string{"kubelet": "10-kubeadm.conf", "thing": "thing"},
+		},
+	}
+
+	v := viper.New()
+	statFunc = fakestat
+
+	for id, c := range cases {
+		t.Run(strconv.Itoa(id), func(t *testing.T) {
+			for k, val := range c.config {
+				v.Set(k, val)
+			}
+			e = c.statResults
+			eIndex = 0
+
+			m := getServiceFiles(v)
+			if !reflect.DeepEqual(m, c.exp) {
+				t.Fatalf("Got %v\nExpected %v", m, c.exp)
+			}
+		})
+	}
+}
+
 func TestMakeSubsitutions(t *testing.T) {
 	cases := []struct {
 		input string