update: refactor config

- Explicitly specify all of the valid options for Update
- Seperate the config from File() and Units()
- Add YAML tags for the fields

system/etc_hosts.go

@@ -0,0 +1,48 @@
+package system
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path"
+
+	"github.com/coreos/coreos-cloudinit/config"
+)
+
+const DefaultIpv4Address = "127.0.0.1"
+
+type EtcHosts struct {
+	Config config.EtcHosts
+}
+
+func (eh EtcHosts) generateEtcHosts() (out string, err error) {
+	if eh.Config != "localhost" {
+		return "", errors.New("Invalid option to manage_etc_hosts")
+	}
+
+	// use the operating system hostname
+	hostname, err := os.Hostname()
+	if err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%s %s\n", DefaultIpv4Address, hostname), nil
+
+}
+
+func (eh EtcHosts) File() (*File, error) {
+	if eh.Config == "" {
+		return nil, nil
+	}
+
+	etcHosts, err := eh.generateEtcHosts()
+	if err != nil {
+		return nil, err
+	}
+
+	return &File{
+		Path:               path.Join("etc", "hosts"),
+		RawFilePermissions: "0644",
+		Content:            etcHosts,
+	}, nil
+}

system/etc_hosts_test.go

@@ -0,0 +1,46 @@
+package system
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/config"
+)
+
+func TestEtcdHostsFile(t *testing.T) {
+	hostname, err := os.Hostname()
+	if err != nil {
+		panic(err)
+	}
+
+	for _, tt := range []struct {
+		config config.EtcHosts
+		file   *File
+		err    error
+	}{
+		{
+			"invalid",
+			nil,
+			fmt.Errorf("Invalid option to manage_etc_hosts"),
+		},
+		{
+			"localhost",
+			&File{
+				Content:            fmt.Sprintf("127.0.0.1 %s\n", hostname),
+				Path:               "etc/hosts",
+				RawFilePermissions: "0644",
+			},
+			nil,
+		},
+	} {
+		file, err := EtcHosts{tt.config}.File()
+		if !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad error (%q): want %q, got %q", tt.config, tt.err, err)
+		}
+		if !reflect.DeepEqual(tt.file, file) {
+			t.Errorf("bad units (%q): want %#v, got %#v", tt.config, tt.file, file)
+		}
+	}
+}

system/etcd.go

@@ -11,7 +11,7 @@ type Etcd struct {
 }
 
 // Units creates a Unit file drop-in for etcd, using any configured options.
-func (ee Etcd) Units(_ string) ([]Unit, error) {
+func (ee Etcd) Units() ([]Unit, error) {
 	content := dropinContents(ee.Etcd)
 	if content == "" {
 		return nil, nil

system/etcd_test.go

@@ -49,7 +49,7 @@ Environment="ETCD_PEER_BIND_ADDR=127.0.0.1:7002"
 			}},
 		},
 	} {
-		units, err := Etcd{tt.config}.Units("")
+		units, err := Etcd{tt.config}.Units()
 		if err != nil {
 			t.Errorf("bad error (%q): want %q, got %q", tt.config, nil, err)
 		}

system/fleet.go

@@ -12,7 +12,7 @@ type Fleet struct {
 
 // Units generates a Unit file drop-in for fleet, if any fleet options were
 // configured in cloud-config
-func (fe Fleet) Units(_ string) ([]Unit, error) {
+func (fe Fleet) Units() ([]Unit, error) {
 	content := dropinContents(fe.Fleet)
 	if content == "" {
 		return nil, nil

system/fleet_test.go

@@ -30,7 +30,7 @@ Environment="FLEET_PUBLIC_IP=12.34.56.78"
 			}},
 		},
 	} {
-		units, err := Fleet{tt.config}.Units("")
+		units, err := Fleet{tt.config}.Units()
 		if err != nil {
 			t.Errorf("bad error (%q): want %q, got %q", tt.config, nil, err)
 		}

system/oem.go

@@ -13,7 +13,7 @@ type OEM struct {
 	config.OEM
 }
 
-func (oem OEM) File(_ string) (*File, error) {
+func (oem OEM) File() (*File, error) {
 	if oem.ID == "" {
 		return nil, nil
 	}

system/oem_test.go

@@ -36,7 +36,7 @@ BUG_REPORT_URL="https://github.com/coreos/coreos-overlay"
 			},
 		},
 	} {
-		file, err := OEM{tt.config}.File("")
+		file, err := OEM{tt.config}.File()
 		if err != nil {
 			t.Errorf("bad error (%q): want %q, got %q", tt.config, nil, err)
 		}

system/update.go

@@ -0,0 +1,137 @@
+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 {
+	Config     config.Update
+	ReadConfig func() (io.Reader, error)
+}
+
+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.Config) {
+		return nil, nil
+	}
+	if err := config.AssertValid(uc.Config); 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.Config)
+	ucv := reflect.ValueOf(uc.Config)
+	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{
+		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, error) {
+	var units []Unit
+	if uc.Config.RebootStrategy != "" {
+		ls := &Unit{
+			Name:    locksmithUnit,
+			Command: "restart",
+			Mask:    false,
+			Runtime: true,
+		}
+
+		if uc.Config.RebootStrategy == "off" {
+			ls.Command = "stop"
+			ls.Mask = true
+		}
+		units = append(units, *ls)
+	}
+
+	if uc.Config.Group != "" || uc.Config.Server != "" {
+		ue := Unit{
+			Name:    updateEngineUnit,
+			Command: "restart",
+		}
+		units = append(units, ue)
+	}
+
+	return units, nil
+}
+
+func sortedKeys(m map[string]string) (keys []string) {
+	for key := range m {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	return
+}

system/update_test.go

@@ -0,0 +1,151 @@
+package system
+
+import (
+	"errors"
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+
+	"github.com/coreos/coreos-cloudinit/config"
+)
+
+func testReadConfig(config string) func() (io.Reader, error) {
+	return func() (io.Reader, error) {
+		return strings.NewReader(config), nil
+	}
+}
+
+func TestUpdateUnits(t *testing.T) {
+	for _, tt := range []struct {
+		config config.Update
+		units  []Unit
+		err    error
+	}{
+		{
+			config: config.Update{},
+		},
+		{
+			config: config.Update{Group: "master", Server: "http://foo.com"},
+			units: []Unit{{
+				Name:    "update-engine.service",
+				Command: "restart",
+			}},
+		},
+		{
+			config: config.Update{RebootStrategy: "best-effort"},
+			units: []Unit{{
+				Name:    "locksmithd.service",
+				Command: "restart",
+				Runtime: true,
+			}},
+		},
+		{
+			config: config.Update{RebootStrategy: "etcd-lock"},
+			units: []Unit{{
+				Name:    "locksmithd.service",
+				Command: "restart",
+				Runtime: true,
+			}},
+		},
+		{
+			config: config.Update{RebootStrategy: "reboot"},
+			units: []Unit{{
+				Name:    "locksmithd.service",
+				Command: "restart",
+				Runtime: true,
+			}},
+		},
+		{
+			config: config.Update{RebootStrategy: "off"},
+			units: []Unit{{
+				Name:    "locksmithd.service",
+				Command: "stop",
+				Runtime: true,
+				Mask:    true,
+			}},
+		},
+	} {
+		units, err := Update{tt.config, testReadConfig("")}.Units()
+		if !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad error (%q): want %q, got %q", tt.config, tt.err, err)
+		}
+		if !reflect.DeepEqual(tt.units, units) {
+			t.Errorf("bad units (%q): want %#v, got %#v", tt.config, tt.units, units)
+		}
+	}
+}
+
+func TestUpdateFile(t *testing.T) {
+	for _, tt := range []struct {
+		config config.Update
+		orig   string
+		file   *File
+		err    error
+	}{
+		{
+			config: config.Update{},
+		},
+		{
+			config: config.Update{RebootStrategy: "wizzlewazzle"},
+			err:    errors.New("invalid value \"wizzlewazzle\" for option \"RebootStrategy\" (valid options: \"best-effort,etcd-lock,reboot,off\")"),
+		},
+		{
+			config: config.Update{Group: "master", Server: "http://foo.com"},
+			file: &File{
+				Content:            "GROUP=master\nSERVER=http://foo.com\n",
+				Path:               "etc/coreos/update.conf",
+				RawFilePermissions: "0644",
+			},
+		},
+		{
+			config: config.Update{RebootStrategy: "best-effort"},
+			file: &File{
+				Content:            "REBOOT_STRATEGY=best-effort\n",
+				Path:               "etc/coreos/update.conf",
+				RawFilePermissions: "0644",
+			},
+		},
+		{
+			config: config.Update{RebootStrategy: "etcd-lock"},
+			file: &File{
+				Content:            "REBOOT_STRATEGY=etcd-lock\n",
+				Path:               "etc/coreos/update.conf",
+				RawFilePermissions: "0644",
+			},
+		},
+		{
+			config: config.Update{RebootStrategy: "reboot"},
+			file: &File{
+				Content:            "REBOOT_STRATEGY=reboot\n",
+				Path:               "etc/coreos/update.conf",
+				RawFilePermissions: "0644",
+			},
+		},
+		{
+			config: config.Update{RebootStrategy: "off"},
+			file: &File{
+				Content:            "REBOOT_STRATEGY=off\n",
+				Path:               "etc/coreos/update.conf",
+				RawFilePermissions: "0644",
+			},
+		},
+		{
+			config: config.Update{RebootStrategy: "etcd-lock"},
+			orig:   "SERVER=https://example.com\nGROUP=thegroupc\nREBOOT_STRATEGY=awesome",
+			file: &File{
+				Content:            "SERVER=https://example.com\nGROUP=thegroupc\nREBOOT_STRATEGY=etcd-lock\n",
+				Path:               "etc/coreos/update.conf",
+				RawFilePermissions: "0644",
+			},
+		},
+	} {
+		file, err := Update{tt.config, testReadConfig(tt.orig)}.File()
+		if !reflect.DeepEqual(tt.err, err) {
+			t.Errorf("bad error (%q): want %q, got %q", tt.config, tt.err, err)
+		}
+		if !reflect.DeepEqual(tt.file, file) {
+			t.Errorf("bad units (%q): want %#v, got %#v", tt.config, tt.file, file)
+		}
+	}
+}