func SetService(service *core.Service) error {
// in case of failure
oldServices, err := database.GetServices()
if err != nil {
return err
}
// apply to balancer
err = balance.SetService(service)
if err != nil {
return err
}
if !database.CentralStore {
// save to backend
err = database.SetService(service)
if err != nil {
// undo balancer action
if uerr := balance.SetServices(oldServices); uerr != nil {
err = fmt.Errorf("%v - %v", err.Error(), uerr.Error())
}
return err
}
}
return nil
}
func TestGetServices(t *testing.T) {
services, err := database.GetServices()
if err != nil {
t.Errorf("Failed to GET services - %v", err)
}
if services[0].Id != testService2.Id {
t.Errorf("Read service differs from written service")
}
}
func TestNoneGetServices(t *testing.T) {
// don't use cluster.GetServices()
services, err := database.GetServices()
if err != nil {
t.Errorf("Failed to GET services - %v", err)
t.FailNow()
}
if services[0].Id != testService2.Id {
t.Errorf("Read service differs from written service")
}
}
// GetServices gets a list of services from the database, or another cluster member.
func (r *Redis) GetServices() ([]core.Service, error) {
if database.CentralStore {
return database.GetServices()
}
conn := pool.Get()
defer conn.Close()
// get known members(other than me) to 'poll' for services
members, _ := redis.Strings(conn.Do("SMEMBERS", "members"))
if len(members) == 0 {
// should only happen on new cluster
// assume i'm ok to be master so don't reset imported services
config.Log.Trace("[cluster] - Assuming OK to be master, using services from my database...")
return common.GetServices()
}
for i := range members {
if members[i] == self {
// if i'm in the list of members, new requests should have failed while `waitForMembers`ing
config.Log.Trace("[cluster] - Assuming I was in sync, using services from my database...")
return common.GetServices()
}
}
c, err := redis.DialURL(config.ClusterConnection, redis.DialConnectTimeout(15*time.Second), redis.DialPassword(config.ClusterToken))
if err != nil {
return nil, fmt.Errorf("Failed to reach redis for services subscriber - %v", err)
}
defer c.Close()
message := make(chan interface{})
subconn := redis.PubSubConn{c}
// subscribe to channel that services will be published on
if err := subconn.Subscribe("services"); err != nil {
return nil, fmt.Errorf("Failed to reach redis for services subscriber - %v", err)
}
defer subconn.Close()
// listen always
go func() {
for {
message <- subconn.Receive()
}
}()
// todo: maybe use ttl?
// timeout is how long to wait for the listed members to come back online
timeout := time.After(time.Duration(20) * time.Second)
// loop attempts for timeout, allows last dead members to start back up
for {
select {
case <-timeout:
return nil, fmt.Errorf("Timed out waiting for services from %v", strings.Join(members, ", "))
default:
// request services from each member until successful
for _, member := range members {
// memberTimeout is how long to wait for a member to respond with list of services
memberTimeout := time.After(3 * time.Second)
// ask a member for its services
config.Log.Trace("[cluster] - Attempting to request services from %v...", member)
_, err := conn.Do("PUBLISH", "portal", fmt.Sprintf("get-services %s", member))
if err != nil {
return nil, err
}
// wait for member to respond
for {
select {
case <-memberTimeout:
config.Log.Debug("[cluster] - Timed out waiting for services from %v", member)
goto nextMember
case msg := <-message:
switch v := msg.(type) {
case redis.Message:
config.Log.Trace("[cluster] - Received message on 'services' channel")
services, err := marshalSvcs(v.Data)
if err != nil {
return nil, fmt.Errorf("Failed to marshal services - %v", err.Error())
}
config.Log.Trace("[cluster] - Services from cluster: %#v\n", *services)
return *services, nil
case error:
return nil, fmt.Errorf("Subscriber failed to receive services - %v", v.Error())
}
}
}
nextMember:
}
}
}
}
func GetServices() ([]core.Service, error) {
return database.GetServices()
}