Implement replicaLoadBalancer boolean flag. (#38)

The flag adds a replica service with the name cluster_name-repl and
a DNS name that defaults to {cluster}-repl.{team}.{hostedzone}.

The implementation converted Service field of the cluster into a map
with one or two elements and deals with the cases when the new flag
is changed on a running cluster
(the update and the sync should create or delete the replica service).
In order to pick up master and replica service and master endpoint
when listing cluster resources.

* Update the spec when updating the cluster.

pkg/util/config/config.go

@@ -43,19 +43,20 @@ type Config struct {
 	TPR
 	Resources
 	Auth
-	Namespace          string         `name:"namespace"`
-	EtcdHost           string         `name:"etcd_host" default:"etcd-client.default.svc.cluster.local:2379"`
-	DockerImage        string         `name:"docker_image" default:"registry.opensource.zalan.do/acid/spiloprivate-9.6:1.2-p4"`
-	ServiceAccountName string         `name:"service_account_name" default:"operator"`
-	DbHostedZone       string         `name:"db_hosted_zone" default:"db.example.com"`
-	EtcdScope          string         `name:"etcd_scope" default:"service"`
-	WALES3Bucket       string         `name:"wal_s3_bucket"`
-	KubeIAMRole        string         `name:"kube_iam_role"`
-	DebugLogging       bool           `name:"debug_logging" default:"true"`
-	EnableDBAccess     bool           `name:"enable_database_access" default:"true"`
-	EnableTeamsAPI     bool           `name:"enable_teams_api" default:"true"`
-	DNSNameFormat      stringTemplate `name:"dns_name_format" default:"{cluster}.{team}.{hostedzone}"`
-	Workers            uint32         `name:"workers" default:"4"`
+	Namespace            string         `name:"namespace"`
+	EtcdHost             string         `name:"etcd_host" default:"etcd-client.default.svc.cluster.local:2379"`
+	DockerImage          string         `name:"docker_image" default:"registry.opensource.zalan.do/acid/spiloprivate-9.6:1.2-p4"`
+	ServiceAccountName   string         `name:"service_account_name" default:"operator"`
+	DbHostedZone         string         `name:"db_hosted_zone" default:"db.example.com"`
+	EtcdScope            string         `name:"etcd_scope" default:"service"`
+	WALES3Bucket         string         `name:"wal_s3_bucket"`
+	KubeIAMRole          string         `name:"kube_iam_role"`
+	DebugLogging         bool           `name:"debug_logging" default:"true"`
+	EnableDBAccess       bool           `name:"enable_database_access" default:"true"`
+	EnableTeamsAPI       bool           `name:"enable_teams_api" default:"true"`
+	MasterDNSNameFormat  stringTemplate `name:"master_dns_name_format" default:"{cluster}.{team}.{hostedzone}"`
+	ReplicaDNSNameFormat stringTemplate `name:"replica_dns_name_format" default:"{cluster}-repl.{team}.{hostedzone}"`
+	Workers              uint32         `name:"workers" default:"4"`
 }
 
 func (c Config) MustMarshal() string {

pkg/util/config/util.go

@@ -9,7 +9,7 @@ import (
 	"time"
 )
 
-type Decoder interface {
+type decoder interface {
 	Decode(value string) error
 }
 
@@ -21,15 +21,15 @@ type fieldInfo struct {
 
 type stringTemplate string
 
-func decoderFrom(field reflect.Value) (d Decoder) {
+func decoderFrom(field reflect.Value) (d decoder) {
 	// it may be impossible for a struct field to fail this check
 	if !field.CanInterface() {
 		return
 	}
 
-	d, ok := field.Interface().(Decoder)
+	d, ok := field.Interface().(decoder)
 	if !ok && field.CanAddr() {
-		d, _ = field.Addr().Interface().(Decoder)
+		d, _ = field.Addr().Interface().(decoder)
 	}
 
 	return d

pkg/util/constants/annotations.go

@@ -1,5 +1,6 @@
 package constants
 
+// Names and values in Kubernetes annotation for services, statefulsets and volumes
 const (
 	ZalandoDNSNameAnnotation           = "external-dns.alpha.kubernetes.io/hostname"
 	ElbTimeoutAnnotationName           = "service.beta.kubernetes.io/aws-load-balancer-connection-idle-timeout"

pkg/util/constants/aws.go

@@ -2,8 +2,11 @@ package constants
 
 import "time"
 
+// AWS specific constants used by other modules
 const (
-	AWS_REGION       = "eu-central-1"
+	// default region for AWS. TODO: move it to the operator configuration
+	AWS_REGION = "eu-central-1"
+	// EBS related constants
 	EBSVolumeIDStart = "/vol-"
 	EBSProvisioner   = "kubernetes.io/aws-ebs"
 	//https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_VolumeModification.html

pkg/util/constants/kubernetes.go

@@ -2,6 +2,7 @@ package constants
 
 import "time"
 
+// General kubernetes-related constants
 const (
 	ListClustersURITemplate     = "/apis/" + TPRVendor + "/" + TPRApiVersion + "/namespaces/%s/" + ResourceName       // Namespace
 	WatchClustersURITemplate    = "/apis/" + TPRVendor + "/" + TPRApiVersion + "/watch/namespaces/%s/" + ResourceName // Namespace

pkg/util/constants/thirdpartyresource.go

@@ -1,5 +1,6 @@
 package constants
 
+// Different properties of the PostgreSQL Third Party Resources
 const (
 	TPRName        = "postgresql"
 	TPRVendor      = "acid.zalan.do"

pkg/util/constants/units.go

@@ -1,5 +1,6 @@
 package constants
 
+// Measurement-unit definitions
 const (
 	Gigabyte = 1073741824
 )

pkg/util/filesystems/ext234.go

@@ -11,19 +11,22 @@ var (
 )
 
 const (
-	EXT2      = "ext2"
-	EXT3      = "ext3"
-	EXT4      = "ext4"
+	ext2      = "ext2"
+	ext3      = "ext3"
+	ext4      = "ext4"
 	resize2fs = "resize2fs"
 )
 
+//  Ext234Resize implements the FilesystemResizer interface for the ext4/3/2fs.
 type Ext234Resize struct {
 }
 
+// CanResizeFilesystem checks whether Ext234Resize can resize this filesystem.
 func (c *Ext234Resize) CanResizeFilesystem(fstype string) bool {
-	return fstype == EXT2 || fstype == EXT3 || fstype == EXT4
+	return fstype == ext2 || fstype == ext3 || fstype == ext4
 }
 
+// ResizeFilesystem calls resize2fs to resize the filesystem if necessary.
 func (c *Ext234Resize) ResizeFilesystem(deviceName string, commandExecutor func(cmd string) (out string, err error)) error {
 	command := fmt.Sprintf("%s %s 2>&1", resize2fs, deviceName)
 	out, err := commandExecutor(command)

pkg/util/retryutil/retry_util.go

@@ -7,6 +7,7 @@ import (
 
 type ConditionFunc func() (bool, error)
 
+// Retry calls ConditionFunc until it returns boolean true, a timeout expires or an error occurs.
 func Retry(interval time.Duration, timeout time.Duration, f ConditionFunc) error {
 	//TODO: make the retry exponential
 	if timeout < interval {

pkg/util/teams/teams.go

@@ -9,7 +9,8 @@ import (
 	"github.com/Sirupsen/logrus"
 )
 
-type InfrastructureAccount struct {
+// InfrastructureAccount defines an account of the team on some infrastructure (i.e AWS, Google) platform.
+type infrastructureAccount struct {
 	ID          string `json:"id"`
 	Name        string `json:"name"`
 	Provider    string `json:"provider"`
@@ -20,7 +21,8 @@ type InfrastructureAccount struct {
 	Disabled    bool   `json:"disabled"`
 }
 
-type Team struct {
+// Team defines informaiton for a single team, including the list of members and infrastructure accounts.
+type team struct {
 	Dn           string   `json:"dn"`
 	ID           string   `json:"id"`
 	TeamName     string   `json:"id_name"`
@@ -34,15 +36,17 @@ type Team struct {
 	DeliveryLead string   `json:"delivery_lead"`
 	ParentTeamID string   `json:"parent_team_id"`
 
-	InfrastructureAccounts []InfrastructureAccount `json:"infrastructure-accounts"`
+	InfrastructureAccounts []infrastructureAccount `json:"infrastructure-accounts"`
 }
 
+//
 type API struct {
 	url        string
 	httpClient *http.Client
 	logger     *logrus.Entry
 }
 
+// NewTeamsAPI creates an object to query the team API.
 func NewTeamsAPI(url string, log *logrus.Logger) *API {
 	t := API{
 		url:        strings.TrimRight(url, "/"),
@@ -53,7 +57,8 @@ func NewTeamsAPI(url string, log *logrus.Logger) *API {
 	return &t
 }
 
-func (t *API) TeamInfo(teamID, token string) (*Team, error) {
+// TeamInfo returns information about a given team using its ID and a token to authenticate to the API service.
+func (t *API) TeamInfo(teamID, token string) (*team, error) {
 	url := fmt.Sprintf("%s/teams/%s", t.url, teamID)
 	t.logger.Debugf("Request url: %s", url)
 	req, err := http.NewRequest("GET", url, nil)
@@ -81,7 +86,7 @@ func (t *API) TeamInfo(teamID, token string) (*Team, error) {
 
 		return nil, fmt.Errorf("team API query failed with status code %d", resp.StatusCode)
 	}
-	teamInfo := &Team{}
+	teamInfo := &team{}
 	d := json.NewDecoder(resp.Body)
 	err = d.Decode(teamInfo)
 	if err != nil {

pkg/util/teams/teams_test.go

@@ -17,7 +17,7 @@ var (
 var teamsAPItc = []struct {
 	in     string
 	inCode int
-	out    *Team
+	out    *team
 	err    error
 }{
 	{`{
@@ -66,7 +66,7 @@ var teamsAPItc = []struct {
 "parent_team_id": "111221"
 }`,
 		200,
-		&Team{
+		&team{
 			Dn:           "cn=100100,ou=official,ou=foobar,dc=zalando,dc=net",
 			ID:           "acid",
 			TeamName:     "ACID",
@@ -79,7 +79,7 @@ var teamsAPItc = []struct {
 			CostCenter:   "00099999",
 			DeliveryLead: "member4",
 			ParentTeamID: "111221",
-			InfrastructureAccounts: []InfrastructureAccount{
+			InfrastructureAccounts: []infrastructureAccount{
 				{
 					ID:          "1234512345",
 					Name:        "acid",

pkg/util/users/users.go

@@ -18,9 +18,14 @@ const (
 	inRoleTemplate   = `IN ROLE %s`
 )
 
+// DefaultUserSyncStrategy implements a user sync strategy that merges already existing database users
+// with those defined in the manifest, altering existing users when necessary. It will never strips
+// an existing roles of another role membership, nor it removes the already assigned flag
+// (except for the NOLOGIN). TODO: process other NOflags, i.e. NOSUPERUSER correctly.
 type DefaultUserSyncStrategy struct {
 }
 
+// ProduceSyncRequests figures out the types of changes that need to happen with the given users.
 func (s DefaultUserSyncStrategy) ProduceSyncRequests(dbUsers spec.PgUserMap,
 	newUsers spec.PgUserMap) (reqs []spec.PgSyncUserRequest) {
 
@@ -55,6 +60,7 @@ func (s DefaultUserSyncStrategy) ProduceSyncRequests(dbUsers spec.PgUserMap,
 	return
 }
 
+// ExecuteSyncRequests makes actual database changes from the requests passed in its arguments.
 func (s DefaultUserSyncStrategy) ExecuteSyncRequests(reqs []spec.PgSyncUserRequest, db *sql.DB) error {
 	for _, r := range reqs {
 		switch r.Kind {

pkg/util/util.go

@@ -3,7 +3,6 @@ package util
 import (
 	"crypto/md5"
 	"encoding/hex"
-	"fmt"
 	"math/rand"
 	"strings"
 	"time"
@@ -24,6 +23,7 @@ func init() {
 	rand.Seed(int64(time.Now().Unix()))
 }
 
+// RandomPassword generates random alphanumeric password of a given length.
 func RandomPassword(n int) string {
 	b := make([]byte, n)
 	for i := range b {
@@ -33,6 +33,7 @@ func RandomPassword(n int) string {
 	return string(b)
 }
 
+// NameFromMeta converts a metadata object to the NamespacedName name representation.
 func NameFromMeta(meta v1.ObjectMeta) spec.NamespacedName {
 	return spec.NamespacedName{
 		Namespace: meta.Namespace,
@@ -40,6 +41,7 @@ func NameFromMeta(meta v1.ObjectMeta) spec.NamespacedName {
 	}
 }
 
+// PGUserPassword is used to generate md5 password hash for a given user. It does nothing for already hashed passwords.
 func PGUserPassword(user spec.PgUser) string {
 	if (len(user.Password) == md5.Size*2+len(md5prefix) && user.Password[:3] == md5prefix) || user.Password == "" {
 		// Avoid processing already encrypted or empty passwords
@@ -49,17 +51,14 @@ func PGUserPassword(user spec.PgUser) string {
 	return md5prefix + hex.EncodeToString(s[:])
 }
 
-func Pretty(x interface{}) (f fmt.Formatter) {
-	return pretty.Formatter(x)
-}
-
+// PrettyDiff shows the diff between 2 objects in an easy to understand format. It is mainly used for debugging output.
 func PrettyDiff(a, b interface{}) (result string) {
 	diff := pretty.Diff(a, b)
 	return strings.Join(diff, "\n")
 }
 
+// SubstractStringSlices finds elements in a that are not in b and return them as a result slice.
 func SubstractStringSlices(a []string, b []string) (result []string, equal bool) {
-	// Find elements in a that are not in b and return them as a result slice
 	// Slices are assumed to contain unique elements only
 OUTER:
 	for _, vala := range a {

pkg/util/volumes/ebs.go

@@ -13,10 +13,12 @@ import (
 	"k8s.io/client-go/pkg/api/v1"
 )
 
+// EBSVolumeResizer implements volume resizing interface for AWS EBS volumes.
 type EBSVolumeResizer struct {
 	connection *ec2.EC2
 }
 
+// ConnectToProvider connects to AWS.
 func (c *EBSVolumeResizer) ConnectToProvider() error {
 	sess, err := session.NewSession(&aws.Config{Region: aws.String(constants.AWS_REGION)})
 	if err != nil {
@@ -26,10 +28,12 @@ func (c *EBSVolumeResizer) ConnectToProvider() error {
 	return nil
 }
 
+// IsConnectedToProvider checks if AWS connection is established.
 func (c *EBSVolumeResizer) IsConnectedToProvider() bool {
 	return c.connection != nil
 }
 
+// VolumeBelongsToProvider checks if the given persistent volume is backed by EBS.
 func (c *EBSVolumeResizer) VolumeBelongsToProvider(pv *v1.PersistentVolume) bool {
 	return pv.Spec.AWSElasticBlockStore != nil && pv.Annotations[constants.VolumeStorateProvisionerAnnotation] == constants.EBSProvisioner
 }
@@ -47,6 +51,7 @@ func (c *EBSVolumeResizer) GetProviderVolumeID(pv *v1.PersistentVolume) (string,
 	return volumeID[idx:], nil
 }
 
+// ResizeVolume actually calls AWS API to resize the EBS volume if necessary.
 func (c *EBSVolumeResizer) ResizeVolume(volumeId string, newSize int64) error {
 	/* first check if the volume is already of a requested size */
 	volumeOutput, err := c.connection.DescribeVolumes(&ec2.DescribeVolumesInput{VolumeIds: []*string{&volumeId}})
@@ -89,7 +94,8 @@ func (c *EBSVolumeResizer) ResizeVolume(volumeId string, newSize int64) error {
 				return false, fmt.Errorf("describe volume modification didn't return one record for volume \"%s\"", volumeId)
 			}
 			if *out.VolumesModifications[0].VolumeId != volumeId {
-				return false, fmt.Errorf("non-matching volume id when describing modifications: \"%s\" is different from \"%s\"")
+				return false, fmt.Errorf("non-matching volume id when describing modifications: \"%s\" is different from \"%s\"",
+					*out.VolumesModifications[0].VolumeId, volumeId)
 			}
 			return *out.VolumesModifications[0].ModificationState != constants.EBSVolumeStateModifying, nil
 		})

pkg/util/volumes/volumes.go

@@ -4,6 +4,7 @@ import (
 	"k8s.io/client-go/pkg/api/v1"
 )
 
+// VolumeResizer defines the set of methods used to implememnt provider-specific resizing of persistent volumes.
 type VolumeResizer interface {
 	ConnectToProvider() error
 	IsConnectedToProvider() bool