move coreos-cloudinit into config/cloudinit

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>

config/cloudinit/system/update.go

@@ -0,0 +1,151 @@
+// 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/rancher/os/config/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 == "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
+}