1// +build !windows 2 3/* 4Copyright 2017 The Kubernetes Authors. 5 6Licensed under the Apache License, Version 2.0 (the "License"); 7you may not use this file except in compliance with the License. 8You may obtain a copy of the License at 9 10 http://www.apache.org/licenses/LICENSE-2.0 11 12Unless required by applicable law or agreed to in writing, software 13distributed under the License is distributed on an "AS IS" BASIS, 14WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15See the License for the specific language governing permissions and 16limitations under the License. 17*/ 18 19package initsystem 20 21import ( 22 "fmt" 23 "os/exec" 24 "strings" 25) 26 27// OpenRCInitSystem defines openrc 28type OpenRCInitSystem struct{} 29 30// ServiceStart tries to start a specific service 31func (openrc OpenRCInitSystem) ServiceStart(service string) error { 32 args := []string{service, "start"} 33 return exec.Command("rc-service", args...).Run() 34} 35 36// ServiceStop tries to stop a specific service 37func (openrc OpenRCInitSystem) ServiceStop(service string) error { 38 args := []string{service, "stop"} 39 return exec.Command("rc-service", args...).Run() 40} 41 42// ServiceRestart tries to reload the environment and restart the specific service 43func (openrc OpenRCInitSystem) ServiceRestart(service string) error { 44 args := []string{service, "restart"} 45 return exec.Command("rc-service", args...).Run() 46} 47 48// ServiceExists ensures the service is defined for this init system. 49// openrc writes to stderr if a service is not found or not enabled 50// this is in contrast to systemd which only writes to stdout. 51// Hence, we use the Combinedoutput, and ignore the error. 52func (openrc OpenRCInitSystem) ServiceExists(service string) bool { 53 args := []string{service, "status"} 54 outBytes, _ := exec.Command("rc-service", args...).CombinedOutput() 55 return !strings.Contains(string(outBytes), "does not exist") 56} 57 58// ServiceIsEnabled ensures the service is enabled to start on each boot. 59func (openrc OpenRCInitSystem) ServiceIsEnabled(service string) bool { 60 args := []string{"show", "default"} 61 outBytes, _ := exec.Command("rc-update", args...).Output() 62 return strings.Contains(string(outBytes), service) 63} 64 65// ServiceIsActive ensures the service is running, or attempting to run. (crash looping in the case of kubelet) 66func (openrc OpenRCInitSystem) ServiceIsActive(service string) bool { 67 args := []string{service, "status"} 68 outBytes, _ := exec.Command("rc-service", args...).CombinedOutput() 69 outStr := string(outBytes) 70 return !strings.Contains(outStr, "stopped") && !strings.Contains(outStr, "does not exist") 71} 72 73// EnableCommand return a string describing how to enable a service 74func (openrc OpenRCInitSystem) EnableCommand(service string) string { 75 return fmt.Sprintf("rc-update add %s default", service) 76} 77 78// SystemdInitSystem defines systemd 79type SystemdInitSystem struct{} 80 81// EnableCommand return a string describing how to enable a service 82func (sysd SystemdInitSystem) EnableCommand(service string) string { 83 return fmt.Sprintf("systemctl enable %s.service", service) 84} 85 86// reloadSystemd reloads the systemd daemon 87func (sysd SystemdInitSystem) reloadSystemd() error { 88 if err := exec.Command("systemctl", "daemon-reload").Run(); err != nil { 89 return fmt.Errorf("failed to reload systemd: %v", err) 90 } 91 return nil 92} 93 94// ServiceStart tries to start a specific service 95func (sysd SystemdInitSystem) ServiceStart(service string) error { 96 // Before we try to start any service, make sure that systemd is ready 97 if err := sysd.reloadSystemd(); err != nil { 98 return err 99 } 100 args := []string{"start", service} 101 return exec.Command("systemctl", args...).Run() 102} 103 104// ServiceRestart tries to reload the environment and restart the specific service 105func (sysd SystemdInitSystem) ServiceRestart(service string) error { 106 // Before we try to restart any service, make sure that systemd is ready 107 if err := sysd.reloadSystemd(); err != nil { 108 return err 109 } 110 args := []string{"restart", service} 111 return exec.Command("systemctl", args...).Run() 112} 113 114// ServiceStop tries to stop a specific service 115func (sysd SystemdInitSystem) ServiceStop(service string) error { 116 args := []string{"stop", service} 117 return exec.Command("systemctl", args...).Run() 118} 119 120// ServiceExists ensures the service is defined for this init system. 121func (sysd SystemdInitSystem) ServiceExists(service string) bool { 122 args := []string{"status", service} 123 outBytes, _ := exec.Command("systemctl", args...).Output() 124 output := string(outBytes) 125 return !strings.Contains(output, "Loaded: not-found") 126} 127 128// ServiceIsEnabled ensures the service is enabled to start on each boot. 129func (sysd SystemdInitSystem) ServiceIsEnabled(service string) bool { 130 args := []string{"is-enabled", service} 131 err := exec.Command("systemctl", args...).Run() 132 return err == nil 133} 134 135// ServiceIsActive will check is the service is "active". In the case of 136// crash looping services (kubelet in our case) status will return as 137// "activating", so we will consider this active as well. 138func (sysd SystemdInitSystem) ServiceIsActive(service string) bool { 139 args := []string{"is-active", service} 140 // Ignoring error here, command returns non-0 if in "activating" status: 141 outBytes, _ := exec.Command("systemctl", args...).Output() 142 output := strings.TrimSpace(string(outBytes)) 143 if output == "active" || output == "activating" { 144 return true 145 } 146 return false 147} 148 149// GetInitSystem returns an InitSystem for the current system, or nil 150// if we cannot detect a supported init system. 151// This indicates we will skip init system checks, not an error. 152func GetInitSystem() (InitSystem, error) { 153 // Assume existence of systemctl in path implies this is a systemd system: 154 _, err := exec.LookPath("systemctl") 155 if err == nil { 156 return &SystemdInitSystem{}, nil 157 } 158 _, err = exec.LookPath("openrc") 159 if err == nil { 160 return &OpenRCInitSystem{}, nil 161 } 162 163 return nil, fmt.Errorf("no supported init system detected, skipping checking for services") 164} 165