added switches package

Author: GrigoriyMikhalkin

cmdutils/switches/switches.go

@@ -0,0 +1,108 @@
+// Copyright 2021 OnMetal authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package switches provides new type that implements flag.Value interface -- Switches.
+// It can be used for enabling/disabling controllers/webhooks in your controller manager.
+package switches
+
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	defaultValue  = "*"
+	disablePrefix = "-"
+)
+
+type Switches struct {
+	settings map[string]bool
+}
+
+// New creates an instance of Switches
+func New(settings []string) *Switches {
+	s := &Switches{
+		settings: make(map[string]bool),
+	}
+	s.setSettings(settings)
+	return s
+}
+
+// Disable prepends disablePrefix prefix to a controller name
+func Disable(name string) string {
+	return disablePrefix + name
+}
+
+func (s *Switches) String() string {
+	return fmt.Sprintf("%v", s.settings)
+}
+
+func (s *Switches) Set(val string) error {
+	s.setSettings(strings.Split(val, ","))
+	return nil
+}
+
+// Enabled checks if controller is enabled
+func (s *Switches) Enabled(name string) bool {
+	return s.settings[name]
+}
+
+// All returns names of all controllers set in settings
+func (s *Switches) All() (names []string) {
+	for k := range s.settings {
+		names = append(names, k)
+	}
+
+	return
+}
+
+// DisabledByDefault returns names of all disabled controllers
+func (s *Switches) DisabledByDefault() (names []string) {
+	for k, enabled := range s.settings {
+		if !enabled {
+			names = append(names, k)
+		}
+	}
+
+	return
+}
+
+func (s *Switches) Type() string {
+	return "Switches"
+}
+
+func (s *Switches) setSettings(settings []string) {
+	if len(settings) == 1 && settings[0] == "" {
+		return
+	}
+
+	var isDefault bool
+	for _, v := range settings {
+		if v == defaultValue {
+			isDefault = true
+			break
+		}
+	}
+
+	if !isDefault {
+		s.settings = make(map[string]bool)
+	}
+
+	for _, v := range settings {
+		if v == defaultValue {
+			continue
+		}
+		s.settings[strings.TrimPrefix(v, disablePrefix)] = !strings.HasPrefix(v, disablePrefix)
+	}
+}

cmdutils/switches/switches_suite_test.go

@@ -0,0 +1,27 @@
+// Copyright 2021 OnMetal authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package switches
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+func TestCondition(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Condition Suite")
+}

cmdutils/switches/switches_test.go

@@ -0,0 +1,68 @@
+// Copyright 2021 OnMetal authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package switches
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("CMD Switches", func() {
+	Context("Setting switches values", func() {
+		It("should disable runner", func() {
+			s := New([]string{"runner-a", Disable("runner-b")})
+			Expect(s.Enabled("runner-a")).To(BeTrue())
+			Expect(s.Enabled("runner-b")).To(BeFalse())
+		})
+		It("should reuse default settings", func() {
+			s := New([]string{"runner-a", Disable("runner-b")})
+			defaults := make(map[string]bool, len(s.settings))
+			for k, v := range s.settings {
+				defaults[k] = v
+			}
+
+			By("updating settings with empty value")
+			Expect(s.Set("")).NotTo(HaveOccurred())
+			Expect(s.settings).To(Equal(defaults))
+
+			By("updating settings with *")
+			Expect(s.Set("*")).NotTo(HaveOccurred())
+			Expect(s.settings).To(Equal(defaults))
+		})
+		It("shouldn't reuse default settings", func() {
+			s := New([]string{"runner-a", Disable("runner-b")})
+			defaults := make(map[string]bool, len(s.settings))
+			for k, v := range s.settings {
+				defaults[k] = v
+			}
+
+			By("updating settings with new values")
+			Expect(s.Set("-runner-a,runner-b")).NotTo(HaveOccurred())
+			Expect(s.settings).ToNot(Equal(defaults))
+		})
+		It("overriding existing settings", func() {
+			s := New([]string{"runner-a", Disable("runner-b")})
+			defaults := make(map[string]bool, len(s.settings))
+			for k, v := range s.settings {
+				defaults[k] = v
+			}
+
+			By("overriding settings")
+			Expect(s.Set("*,runner-b")).NotTo(HaveOccurred())
+			Expect(s.settings).ToNot(Equal(defaults))
+			defaults["runner-b"] = true
+			Expect(s.settings).To(Equal(defaults))
+		})
+	})
+})