package initialize import ( "bufio" "errors" "fmt" "os" "path" "strings" "github.com/coreos/coreos-cloudinit/system" ) const ( locksmithUnit = "locksmithd.service" ) // updateOption represents a configurable update option, which, if set, will be // written into update.conf, replacing any existing value for the option type updateOption struct { key string // key used to configure this option in cloud-config valid []string // valid values for the option prefix string // prefix for the option in the update.conf file value string // used to store the new value in update.conf (including prefix) seen bool // whether the option has been seen in any existing update.conf } // updateOptions defines the update options understood by cloud-config. // The keys represent the string used in cloud-config to configure the option. var updateOptions = []*updateOption{ &updateOption{ key: "reboot-strategy", prefix: "REBOOT_STRATEGY=", valid: []string{"best-effort", "etcd-lock", "reboot", "off"}, }, &updateOption{ key: "group", prefix: "GROUP=", valid: []string{"master", "beta", "alpha", "stable"}, }, &updateOption{ key: "server", prefix: "SERVER=", }, } // isValid checks whether a supplied value is valid for this option func (uo updateOption) isValid(val string) bool { if len(uo.valid) == 0 { return true } for _, v := range uo.valid { if val == v { return true } } return false } type UpdateConfig map[string]string // File generates an `/etc/coreos/update.conf` file (if any update // configuration options are set in cloud-config) by either rewriting the // existing file on disk, or starting from `/usr/share/coreos/update.conf` func (uc UpdateConfig) File(root string) (*system.File, error) { if len(uc) < 1 { return nil, nil } var out string // Generate the list of possible substitutions to be performed based on the options that are configured subs := make([]*updateOption, 0) for _, uo := range updateOptions { val, ok := uc[uo.key] if !ok { continue } if !uo.isValid(val) { return nil, errors.New(fmt.Sprintf("invalid value %v for option %v (valid options: %v)", val, uo.key, uo.valid)) } uo.value = uo.prefix + val subs = append(subs, uo) } etcUpdate := path.Join(root, "etc", "coreos", "update.conf") usrUpdate := path.Join(root, "usr", "share", "coreos", "update.conf") conf, err := os.Open(etcUpdate) if os.IsNotExist(err) { conf, err = os.Open(usrUpdate) } if err != nil { return nil, err } scanner := bufio.NewScanner(conf) for scanner.Scan() { line := scanner.Text() for _, s := range subs { if strings.HasPrefix(line, s.prefix) { line = s.value s.seen = true break } } out += line out += "\n" if err := scanner.Err(); err != nil { return nil, err } } for _, s := range subs { if !s.seen { out += s.value out += "\n" } } return &system.File{ Path: path.Join("etc", "coreos", "update.conf"), RawFilePermissions: "0644", Content: out, }, nil } // GetUnit generates a locksmith system.Unit, if reboot-strategy was set in // cloud-config, for the cloud-init initializer to act on appropriately func (uc UpdateConfig) Unit(root string) (*system.Unit, error) { strategy, ok := uc["reboot-strategy"] if !ok { return nil, nil } u := &system.Unit{ Name: locksmithUnit, Command: "restart", Mask: false, } if strategy == "off" { u.Command = "stop" u.Mask = true } return u, nil }