add method to send message to groups

changelog/unreleased/notifications-service.md

@@ -0,0 +1,5 @@
+Enhancement: Implement notifications service
+
+Implemented the minimal version of the notifications service to be able to notify a user when they received a share.
+
+https://github.com/owncloud/ocis/pull/3217

notifications/pkg/channels/channels.go

@@ -6,18 +6,20 @@ import (
 	"net/smtp"
 
 	gateway "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
+	groups "github.com/cs3org/go-cs3apis/cs3/identity/group/v1beta1"
+	rpc "github.com/cs3org/go-cs3apis/cs3/rpc/v1beta1"
 	"github.com/cs3org/reva/pkg/rgrpc/todo/pool"
 	"github.com/owncloud/ocis/notifications/pkg/config"
 	"github.com/owncloud/ocis/ocis-pkg/log"
+	"github.com/pkg/errors"
 )
 
 // Channel defines the methods of a communication channel.
 type Channel interface {
-	// Todo(c0rby): Do we need a PrepareMessage method?
-	// Maybe channels need to format the message or will the caller
-	// of SendMessage do that?
-	// SendMessage sends a message in a channel specific way.
-	SendMessage(receiver, msg string) error
+	// SendMessage sends a message to users.
+	SendMessage(userIDs []string, msg string) error
+	// SendMessageToGroup sends a message to a group.
+	SendMessageToGroup(groupdID *groups.GroupId, msg string) error
 }
 
 // NewMailChannel instantiates a new mail communication channel.
@@ -30,6 +32,7 @@ func NewMailChannel(cfg config.Config, logger log.Logger) (Channel, error) {
 	return Mail{
 		gatewayClient: gc,
 		conf:          cfg,
+		logger:        logger,
 	}, nil
 }
 
@@ -37,21 +40,66 @@ func NewMailChannel(cfg config.Config, logger log.Logger) (Channel, error) {
 type Mail struct {
 	gatewayClient gateway.GatewayAPIClient
 	conf          config.Config
+	logger        log.Logger
 }
 
-func (m Mail) SendMessage(receiver, msg string) error {
-	smtpConf := m.conf.Notifications.SMTP
-	res, err := m.gatewayClient.Authenticate(context.Background(), &gateway.AuthenticateRequest{
-		Type:         "machine",
-		ClientId:     "userid:" + receiver,
-		ClientSecret: m.conf.Notifications.MachineAuthSecret,
-	})
+// SendMessage sends a message to all given users.
+func (m Mail) SendMessage(userIDs []string, msg string) error {
+	to, err := m.getReceiverAddresses(userIDs)
 	if err != nil {
 		return err
 	}
-
-	to := []string{res.User.Mail}
 	body := []byte(msg)
+
+	smtpConf := m.conf.Notifications.SMTP
 	auth := smtp.PlainAuth("", smtpConf.Sender, smtpConf.Password, smtpConf.Host)
-	return smtp.SendMail(smtpConf.Host+":"+smtpConf.Port, auth, smtpConf.Sender, to, body)
+	if err := smtp.SendMail(smtpConf.Host+":"+smtpConf.Port, auth, smtpConf.Sender, to, body); err != nil {
+		return errors.Wrap(err, "could not send mail")
+	}
+	return nil
+}
+
+// SendMessageToGroup sends a message to all members of the given group.
+func (m Mail) SendMessageToGroup(groupID *groups.GroupId, msg string) error {
+	// TODO We need an authenticated context here...
+	res, err := m.gatewayClient.GetGroup(context.Background(), &groups.GetGroupRequest{GroupId: groupID})
+	if err != nil {
+		return err
+	}
+	if res.Status.Code != rpc.Code_CODE_OK {
+		return errors.New("could not get group")
+	}
+
+	members := make([]string, 0, len(res.Group.Members))
+	for _, id := range res.Group.Members {
+		members = append(members, id.OpaqueId)
+	}
+
+	return m.SendMessage(members, msg)
+}
+
+func (m Mail) getReceiverAddresses(receivers []string) ([]string, error) {
+	addresses := make([]string, 0, len(receivers))
+	for _, id := range receivers {
+		// Authenticate is too costly but at the moment our only option to get the user.
+		// We don't have an authenticated context so calling `GetUser` doesn't work.
+		res, err := m.gatewayClient.Authenticate(context.Background(), &gateway.AuthenticateRequest{
+			Type:         "machine",
+			ClientId:     "userid:" + id,
+			ClientSecret: m.conf.Notifications.MachineAuthSecret,
+		})
+		if err != nil {
+			return nil, err
+		}
+		if res.Status.Code != rpc.Code_CODE_OK {
+			m.logger.Error().
+				Interface("status", res.Status).
+				Str("receiver_id", id).
+				Msg("could not get user")
+			continue
+		}
+		addresses = append(addresses, res.User.Mail)
+	}
+
+	return addresses, nil
 }

notifications/pkg/service/service.go

@@ -40,9 +40,17 @@ func (s eventsNotifier) Run() error {
 			go func() {
 				switch e := evt.(type) {
 				case events.ShareCreated:
-					if err := s.channel.SendMessage(e.GranteeUserID.OpaqueId, "You got a share"); err != nil {
+					msg := "You got a share!"
+					var err error
+					if e.GranteeUserID != nil {
+						err = s.channel.SendMessage([]string{e.GranteeUserID.OpaqueId}, msg)
+					} else if e.GranteeGroupID != nil {
+						err = s.channel.SendMessageToGroup(e.GranteeGroupID, msg)
+					}
+					if err != nil {
 						s.logger.Error().
 							Err(err).
+							Str("event", "ShareCreated").
 							Msg("failed to send a message")
 					}
 				}