// StartDHCP ListenAndServe for dhcp on port 67, binds on interface=ifName if it's
// not empty
func StartDHCP(ifName string, serverIP net.IP, datasource datasource.DataSource) error {
handler := &Handler{
ifName: ifName,
serverIP: serverIP,
datasource: datasource,
bootMessage: fmt.Sprintf("Blacksmith (%s)", datasource.SelfInfo().Version),
}
log.WithFields(log.Fields{
"where": "dhcp.StartDHCP",
"action": "announce",
}).Infof("Listening on %s:67 (interface: %s)", serverIP.String(), ifName)
var err error
if ifName != "" {
err = dhcp4.ListenAndServeIf(ifName, handler)
} else {
err = dhcp4.ListenAndServe(handler)
}
// https://groups.google.com/forum/#!topic/coreos-user/Qbn3OdVtrZU
if len(datasource.ClusterName()) > 50 { // 63 - 12(mac) - 1(.)
log.WithField("where", "dhcp.StartDHCP").Warn(
"Warning: ClusterName is too long. It may break the behaviour of the DHCP clients")
}
rand.Seed(time.Now().UTC().UnixNano())
return err
}
func executeTemplate(rootTemplte *template.Template, templateName string,
ds datasource.DataSource, machineInterface datasource.MachineInterface,
webServerAddr string) (string, error) {
template := rootTemplte.Lookup(templateName)
if template == nil {
return "", fmt.Errorf("template with name=%s wasn't found for root=%v",
templateName, rootTemplte)
}
mac := machineInterface.Mac().String()
buf := new(bytes.Buffer)
template.Funcs(map[string]interface{}{
"V": func(key string) string {
value, err := machineInterface.GetVariable(key)
if err != nil {
log.WithField("where", "templating.executeTemplate").WithError(err).Warn(
"error while GetVariable")
}
return value
},
"b64": func(text string) string {
return base64.StdEncoding.EncodeToString([]byte(text))
},
"b64template": func(templateName string) string {
text, err := executeTemplate(rootTemplte, templateName, ds, machineInterface, webServerAddr)
if err != nil {
log.WithField("where", "templating.executeTemplate").WithError(err).Warnf(
"error while executeTemplate(templateName=%s machine=%s)",
templateName, mac)
return ""
}
return base64.StdEncoding.EncodeToString([]byte(text))
},
})
etcdMembers, _ := ds.EtcdMembers()
machine, err := machineInterface.Machine(false, nil)
if err != nil {
return "", err
}
data := struct {
Mac string
IP string
Hostname string
Domain string
WebServerAddr string
EtcdEndpoints string
}{
mac,
machine.IP.String(),
machineInterface.Hostname(),
ds.ClusterName(),
webServerAddr,
etcdMembers,
}
err = template.ExecuteTemplate(buf, templateName, &data)
if err != nil {
return "", err
}
str := buf.String()
str = strings.Trim(str, "\n")
return str, nil
}