|
| 1 | +package function |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "log" |
| 6 | + "staticbackend/db" |
| 7 | + "staticbackend/internal" |
| 8 | + "time" |
| 9 | + |
| 10 | + "github.com/go-co-op/gocron" |
| 11 | + "go.mongodb.org/mongo-driver/bson" |
| 12 | + "go.mongodb.org/mongo-driver/bson/primitive" |
| 13 | + "go.mongodb.org/mongo-driver/mongo" |
| 14 | +) |
| 15 | + |
| 16 | +type TaskScheduler struct { |
| 17 | + Client *mongo.Client |
| 18 | + Volatile internal.PubSuber |
| 19 | + Scheduler *gocron.Scheduler |
| 20 | +} |
| 21 | + |
| 22 | +const ( |
| 23 | + TaskTypeFunction = "function" |
| 24 | + TaskTypeMessage = "message" |
| 25 | +) |
| 26 | + |
| 27 | +type Task struct { |
| 28 | + ID primitive.ObjectID `bson:"_id" json:"id"` |
| 29 | + Name string `bson:"name" json:"name"` |
| 30 | + Type string `bson:"type" json:"type"` |
| 31 | + Value string `bson:"value" json:"value"` |
| 32 | + Meta interface{} `bson:"meta" json:"meta"` |
| 33 | + Interval string `bson:"invertal" json:"interval"` |
| 34 | + LastRun time.Time `bson:"last" json:"last"` |
| 35 | + |
| 36 | + BaseName string `bson:"-" json:"base"` |
| 37 | +} |
| 38 | + |
| 39 | +type MetaMessage struct { |
| 40 | + Data string `bson:"data" json:"data"` |
| 41 | + Channel string `bson:"channel" json:"channel"` |
| 42 | +} |
| 43 | + |
| 44 | +func (ts *TaskScheduler) Start() { |
| 45 | + tasks, err := ts.listTasks() |
| 46 | + if err != nil { |
| 47 | + log.Println("error loading tasks: %v", err) |
| 48 | + return |
| 49 | + } |
| 50 | + |
| 51 | + ts.Scheduler = gocron.NewScheduler(time.UTC) |
| 52 | + ts.Scheduler.TagsUnique() |
| 53 | + |
| 54 | + for _, task := range tasks { |
| 55 | + _, err := ts.Scheduler.Cron(task.Interval).Tag(task.ID.Hex()).Do(ts.run, task) |
| 56 | + if err != nil { |
| 57 | + log.Println("error scheduling this task: %s -> %v", task.ID.Hex(), err) |
| 58 | + } |
| 59 | + } |
| 60 | +} |
| 61 | + |
| 62 | +func (ts *TaskScheduler) listTasks() ([]Task, error) { |
| 63 | + bases, err := internal.ListDatabases(ts.Client.Database("sbsys")) |
| 64 | + if err != nil { |
| 65 | + return nil, err |
| 66 | + } |
| 67 | + |
| 68 | + filter := bson.M{} |
| 69 | + |
| 70 | + //TODO: Might be worth doing this concurrently |
| 71 | + var results []Task |
| 72 | + |
| 73 | + ctx := context.Background() |
| 74 | + |
| 75 | + for _, base := range bases { |
| 76 | + db := ts.Client.Database(base.Name) |
| 77 | + cur, err := db.Collection("sb_tasks").Find(ctx, filter) |
| 78 | + if err != nil { |
| 79 | + return nil, err |
| 80 | + } |
| 81 | + defer cur.Close(ctx) |
| 82 | + |
| 83 | + var tasks []Task |
| 84 | + |
| 85 | + for cur.Next(ctx) { |
| 86 | + var t Task |
| 87 | + if err := cur.Decode(&t); err != nil { |
| 88 | + return nil, err |
| 89 | + } |
| 90 | + |
| 91 | + t.BaseName = base.Name |
| 92 | + |
| 93 | + tasks = append(tasks, t) |
| 94 | + } |
| 95 | + if err := cur.Err(); err != nil { |
| 96 | + return nil, err |
| 97 | + } |
| 98 | + |
| 99 | + results = append(results, tasks...) |
| 100 | + } |
| 101 | + |
| 102 | + return results, nil |
| 103 | +} |
| 104 | + |
| 105 | +func (ts *TaskScheduler) run(task Task) { |
| 106 | + curDB := ts.Client.Database(task.BaseName) |
| 107 | + |
| 108 | + // the task must run as the root base user |
| 109 | + var auth internal.Auth |
| 110 | + if err := ts.Volatile.GetTyped("root:"+task.BaseName, &auth); err != nil { |
| 111 | + tok, err := internal.GetRootForBase(curDB) |
| 112 | + if err != nil { |
| 113 | + log.Printf("error finding root token for base %s: %v\n", task.BaseName, err) |
| 114 | + return |
| 115 | + } |
| 116 | + |
| 117 | + auth = internal.Auth{ |
| 118 | + AccountID: tok.AccountID, |
| 119 | + UserID: tok.ID, |
| 120 | + Email: tok.Email, |
| 121 | + Role: tok.Role, |
| 122 | + Token: tok.Token, |
| 123 | + } |
| 124 | + |
| 125 | + if err := ts.Volatile.SetTyped("root:"+task.BaseName, auth); err != nil { |
| 126 | + log.Printf("error setting auth inside TaskScheduler.run: ", err) |
| 127 | + return |
| 128 | + } |
| 129 | + } |
| 130 | + |
| 131 | + switch task.Type { |
| 132 | + case TaskTypeFunction: |
| 133 | + ts.execFunction(curDB, auth, task) |
| 134 | + case TaskTypeMessage: |
| 135 | + ts.sendMessage(curDB, auth, task) |
| 136 | + } |
| 137 | +} |
| 138 | + |
| 139 | +func (ts *TaskScheduler) execFunction(curDB *mongo.Database, auth internal.Auth, task Task) { |
| 140 | + |
| 141 | + fn, err := GetForExecution(curDB, task.Value) |
| 142 | + if err != nil { |
| 143 | + log.Printf("cannot find function %s on task %s", task.Value, task.ID.Hex()) |
| 144 | + return |
| 145 | + } |
| 146 | + |
| 147 | + exe := &ExecutionEnvironment{ |
| 148 | + Auth: auth, |
| 149 | + DB: curDB, |
| 150 | + Base: &db.Base{PublishDocument: ts.Volatile.PublishDocument}, |
| 151 | + Volatile: ts.Volatile, |
| 152 | + Data: fn, |
| 153 | + } |
| 154 | + |
| 155 | + if err := exe.Execute(); err != nil { |
| 156 | + log.Printf("error executing function %s: %v", task.Value, err) |
| 157 | + } |
| 158 | +} |
| 159 | + |
| 160 | +func (ts *TaskScheduler) sendMessage(curDB *mongo.Database, auth internal.Auth, task Task) { |
| 161 | + token := auth.ReconstructToken() |
| 162 | + |
| 163 | + meta, ok := task.Meta.(MetaMessage) |
| 164 | + if !ok { |
| 165 | + log.Println("unable to get meta data for type MetaMessage for task: ", task.ID.Hex()) |
| 166 | + return |
| 167 | + } |
| 168 | + |
| 169 | + msg := internal.Command{ |
| 170 | + SID: task.ID.Hex(), |
| 171 | + Type: task.Value, |
| 172 | + Data: meta.Data, |
| 173 | + Channel: meta.Channel, |
| 174 | + Token: token, |
| 175 | + } |
| 176 | + |
| 177 | + if err := ts.Volatile.Publish(msg); err != nil { |
| 178 | + log.Println("error publishing message from task", task.ID.Hex(), err) |
| 179 | + } |
| 180 | +} |
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