/* Should contain a form value dbname which equals the database name
e.g. curl www.hostname.com/backup/now -X POST -d "dbname=nameofdatabase"
The {how} should be either "now" or "enqueue" */
func BackupHandler(w http.ResponseWriter, request *http.Request) {
vars := mux.Vars(request)
dbname := request.FormValue("dbname")
t := tasks.NewTask()
t.Action = "BackupDatabase"
t.Data = dbname
t.Node = globals.MyIP
t.Role = globals.ServiceRole
t.TTL = 3600
t.ClusterService = globals.ClusterService
t.NodeType = "read"
if consul.IsWriteNode(globals.MyIP) {
t.NodeType = "write"
}
var err error
if dbname != "rdpg" {
//Using FindByDatabase to determine if the database actually exists to be backed up.
inst, err := instances.FindByDatabase(dbname)
if err != nil {
log.Error(fmt.Sprintf("admin.BackupHandler() instances.FindByDatabase(%s) Error occurred when searching for database.", dbname))
w.WriteHeader(http.StatusInternalServerError)
w.Write([]byte("Error encountered while searching for database"))
return
}
if inst == nil {
//...then the database doesn't exist on this cluster.
log.Debug(fmt.Sprintf("admin.BackupHandler() Attempt to initiate backup on non-existant database with name: %s", dbname))
w.WriteHeader(http.StatusNotFound)
w.Write([]byte("Database not found"))
return
}
}
switch vars[`how`] {
//Immediately calls Backup() and performs the backup
case "now":
err = t.BackupDatabase()
if err != nil {
log.Error(fmt.Sprintf(`api.BackupHandler() Task.BackupDatabase() %+v ! %s`, t, err))
w.WriteHeader(http.StatusInternalServerError)
w.Write([]byte("Error encountered while trying to perform backup"))
return
}
w.Write([]byte("Backup completed."))
case "enqueue":
// Queues up a backup to be done with a worker thread gets around to it.
// This call returns after the queuing process is done; not after the backup is done.
err = t.Enqueue()
if err != nil {
log.Error(fmt.Sprintf(`api.BackupHandler() Task.Enqueue() %+v ! %s`, t, err))
w.WriteHeader(http.StatusInternalServerError)
w.Write([]byte("Error while trying to queue"))
return
}
w.Write([]byte("Backup successfully queued."))
}
}
//Work - Select a task from the queue for this server
func Work() {
err := OpenWorkDB()
if err != nil {
log.Error(fmt.Sprintf("tasks.Work() OpenWorkDB() %s", err))
proc, _ := os.FindProcess(os.Getpid())
proc.Signal(syscall.SIGTERM)
}
err = OpenWorkDB()
if err != nil {
log.Error(fmt.Sprintf("tasks.Work() OpenWorkDB() %s", err))
proc, _ := os.FindProcess(os.Getpid())
proc.Signal(syscall.SIGTERM)
}
defer CloseWorkDB()
for {
tasks := []Task{}
err = WorkLock()
if err != nil {
time.Sleep(10 * time.Second)
continue
}
nodeType := `read`
if consul.IsWriteNode(globals.MyIP) {
nodeType = `write`
}
sq := fmt.Sprintf(`SELECT id,cluster_id,node,role,action,data,ttl,node_type,cluster_service FROM tasks.tasks WHERE locked_by IS NULL AND role IN ('all','%s') AND node IN ('*','%s') AND node_type IN ('any','%s') ORDER BY created_at DESC LIMIT 1`, globals.ServiceRole, globals.MyIP, nodeType)
log.Trace(fmt.Sprintf(`tasks.Work() > %s`, sq))
err = workDB.Select(&tasks, sq)
if err != nil {
WorkUnlock()
if err == sql.ErrNoRows {
log.Trace(`tasks.Work() No tasks found.`)
} else {
log.Error(fmt.Sprintf(`tasks.Work() Selecting Task ! %s`, err))
}
time.Sleep(5 * time.Second)
continue
}
if len(tasks) == 0 {
WorkUnlock()
time.Sleep(5 * time.Second)
continue
}
task := tasks[0]
err = task.Dequeue()
if err != nil {
log.Error(fmt.Sprintf(`tasks.Work() Task<%d>#Dequeue() ! %s`, task.ID, err))
continue
}
WorkUnlock()
// TODO: Come back and have a cleanup routine for tasks that were locked
// but never finished past the TTL, perhaps a health check or such.
err = task.Work()
if err != nil {
log.Error(fmt.Sprintf(`tasks.Task<%d>#Work() ! %s`, task.ID, err))
sq = fmt.Sprintf(`UPDATE tasks.tasks SET locked_by=NULL, processing_at=NULL WHERE id=%d`, task.ID)
log.Trace(fmt.Sprintf(`tasks#Work() > %s`, sq))
_, err = workDB.Exec(sq)
if err != nil {
log.Error(fmt.Sprintf(`tasks.Work() Updating Task %d processing_at ! %s`, task.ID, err))
}
continue
} else {
// TODO: (t *Task) Delete()
sq = fmt.Sprintf(`DELETE FROM tasks.tasks WHERE id=%d`, task.ID)
log.Trace(fmt.Sprintf(`tasks#Work() > %s`, sq))
_, err = workDB.Exec(sq)
if err != nil {
log.Error(fmt.Sprintf(`tasks.Work() Deleting Task %d ! %s`, task.ID, err))
continue
}
log.Trace(fmt.Sprintf(`tasks.Work() Task Completed! > %+v`, task))
}
}
}