cloudinit/system/update.go
Jonathan Boulle be68a8e5cc *: switch to line comments for copyright
Build tags are not compatible with block comments. Also adds copyright
header to a few places it was missing.
2015-01-24 19:32:33 -08:00

152 lines
3.7 KiB
Go

// Copyright 2015 CoreOS, Inc.
//
// 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 system
import (
"bufio"
"fmt"
"io"
"os"
"path"
"reflect"
"sort"
"strings"
"github.com/coreos/coreos-cloudinit/config"
)
const (
locksmithUnit = "locksmithd.service"
updateEngineUnit = "update-engine.service"
)
// Update is a top-level structure which contains its underlying configuration,
// config.Update, a function for reading the configuration (the default
// implementation reading from the filesystem), and provides the system-specific
// File() and Unit().
type Update struct {
ReadConfig func() (io.Reader, error)
config.Update
}
func DefaultReadConfig() (io.Reader, error) {
etcUpdate := path.Join("/etc", "coreos", "update.conf")
usrUpdate := path.Join("/usr", "share", "coreos", "update.conf")
f, err := os.Open(etcUpdate)
if os.IsNotExist(err) {
f, err = os.Open(usrUpdate)
}
return f, err
}
// 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 Update) File() (*File, error) {
if config.IsZero(uc.Update) {
return nil, nil
}
if err := config.AssertStructValid(uc.Update); err != nil {
return nil, err
}
// Generate the list of possible substitutions to be performed based on the options that are configured
subs := map[string]string{}
uct := reflect.TypeOf(uc.Update)
ucv := reflect.ValueOf(uc.Update)
for i := 0; i < uct.NumField(); i++ {
val := ucv.Field(i).String()
if val == "" {
continue
}
env := uct.Field(i).Tag.Get("env")
subs[env] = fmt.Sprintf("%s=%s", env, val)
}
conf, err := uc.ReadConfig()
if err != nil {
return nil, err
}
scanner := bufio.NewScanner(conf)
var out string
for scanner.Scan() {
line := scanner.Text()
for env, value := range subs {
if strings.HasPrefix(line, env) {
line = value
delete(subs, env)
break
}
}
out += line
out += "\n"
if err := scanner.Err(); err != nil {
return nil, err
}
}
for _, key := range sortedKeys(subs) {
out += subs[key]
out += "\n"
}
return &File{config.File{
Path: path.Join("etc", "coreos", "update.conf"),
RawFilePermissions: "0644",
Content: out,
}}, nil
}
// Units generates units for the cloud-init initializer to act on:
// - a locksmith Unit, if "reboot-strategy" was set in cloud-config
// - an update_engine Unit, if "group" or "server" was set in cloud-config
func (uc Update) Units() []Unit {
var units []Unit
if uc.Update.RebootStrategy != "" {
ls := &Unit{config.Unit{
Name: locksmithUnit,
Command: "restart",
Mask: false,
Runtime: true,
}}
if uc.Update.RebootStrategy == "false" || uc.Update.RebootStrategy == "off" {
ls.Command = "stop"
ls.Mask = true
}
units = append(units, *ls)
}
if uc.Update.Group != "" || uc.Update.Server != "" {
ue := Unit{config.Unit{
Name: updateEngineUnit,
Command: "restart",
}}
units = append(units, ue)
}
return units
}
func sortedKeys(m map[string]string) (keys []string) {
for key := range m {
keys = append(keys, key)
}
sort.Strings(keys)
return
}