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pocketbase/apis/realtime.go
2024-02-17 15:01:09 +02:00

594 lines
17 KiB
Go

package apis
import (
"context"
"encoding/json"
"errors"
"log/slog"
"net/http"
"strings"
"time"
"github.com/labstack/echo/v5"
"github.com/pocketbase/dbx"
"github.com/pocketbase/pocketbase/core"
"github.com/pocketbase/pocketbase/forms"
"github.com/pocketbase/pocketbase/models"
"github.com/pocketbase/pocketbase/resolvers"
"github.com/pocketbase/pocketbase/tools/rest"
"github.com/pocketbase/pocketbase/tools/routine"
"github.com/pocketbase/pocketbase/tools/search"
"github.com/pocketbase/pocketbase/tools/subscriptions"
"github.com/spf13/cast"
)
// bindRealtimeApi registers the realtime api endpoints.
func bindRealtimeApi(app core.App, rg *echo.Group) {
api := realtimeApi{app: app}
subGroup := rg.Group("/realtime")
subGroup.GET("", api.connect)
subGroup.POST("", api.setSubscriptions, ActivityLogger(app))
api.bindEvents()
}
type realtimeApi struct {
app core.App
}
func (api *realtimeApi) connect(c echo.Context) error {
cancelCtx, cancelRequest := context.WithCancel(c.Request().Context())
defer cancelRequest()
c.SetRequest(c.Request().Clone(cancelCtx))
// register new subscription client
client := subscriptions.NewDefaultClient()
api.app.SubscriptionsBroker().Register(client)
defer func() {
disconnectEvent := &core.RealtimeDisconnectEvent{
HttpContext: c,
Client: client,
}
if err := api.app.OnRealtimeDisconnectRequest().Trigger(disconnectEvent); err != nil {
api.app.Logger().Debug(
"OnRealtimeDisconnectRequest error",
slog.String("clientId", client.Id()),
slog.String("error", err.Error()),
)
}
api.app.SubscriptionsBroker().Unregister(client.Id())
}()
c.Response().Header().Set("Content-Type", "text/event-stream")
c.Response().Header().Set("Cache-Control", "no-store")
// https://github.com/pocketbase/pocketbase/discussions/480#discussioncomment-3657640
// https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_buffering
c.Response().Header().Set("X-Accel-Buffering", "no")
connectEvent := &core.RealtimeConnectEvent{
HttpContext: c,
Client: client,
IdleTimeout: 5 * time.Minute,
}
if err := api.app.OnRealtimeConnectRequest().Trigger(connectEvent); err != nil {
return err
}
api.app.Logger().Debug("Realtime connection established.", slog.String("clientId", client.Id()))
// signalize established connection (aka. fire "connect" message)
connectMsgEvent := &core.RealtimeMessageEvent{
HttpContext: c,
Client: client,
Message: &subscriptions.Message{
Name: "PB_CONNECT",
Data: []byte(`{"clientId":"` + client.Id() + `"}`),
},
}
connectMsgErr := api.app.OnRealtimeBeforeMessageSend().Trigger(connectMsgEvent, func(e *core.RealtimeMessageEvent) error {
w := e.HttpContext.Response()
w.Write([]byte("id:" + client.Id() + "\n"))
w.Write([]byte("event:" + e.Message.Name + "\n"))
w.Write([]byte("data:"))
w.Write(e.Message.Data)
w.Write([]byte("\n\n"))
w.Flush()
return api.app.OnRealtimeAfterMessageSend().Trigger(e)
})
if connectMsgErr != nil {
api.app.Logger().Debug(
"Realtime connection closed (failed to deliver PB_CONNECT)",
slog.String("clientId", client.Id()),
slog.String("error", connectMsgErr.Error()),
)
return nil
}
// start an idle timer to keep track of inactive/forgotten connections
idleTimeout := connectEvent.IdleTimeout
idleTimer := time.NewTimer(idleTimeout)
defer idleTimer.Stop()
for {
select {
case <-idleTimer.C:
cancelRequest()
case msg, ok := <-client.Channel():
if !ok {
// channel is closed
api.app.Logger().Debug(
"Realtime connection closed (closed channel)",
slog.String("clientId", client.Id()),
)
return nil
}
msgEvent := &core.RealtimeMessageEvent{
HttpContext: c,
Client: client,
Message: &msg,
}
msgErr := api.app.OnRealtimeBeforeMessageSend().Trigger(msgEvent, func(e *core.RealtimeMessageEvent) error {
w := e.HttpContext.Response()
w.Write([]byte("id:" + e.Client.Id() + "\n"))
w.Write([]byte("event:" + e.Message.Name + "\n"))
w.Write([]byte("data:"))
w.Write(e.Message.Data)
w.Write([]byte("\n\n"))
w.Flush()
return api.app.OnRealtimeAfterMessageSend().Trigger(msgEvent)
})
if msgErr != nil {
api.app.Logger().Debug(
"Realtime connection closed (failed to deliver message)",
slog.String("clientId", client.Id()),
slog.String("error", msgErr.Error()),
)
return nil
}
idleTimer.Stop()
idleTimer.Reset(idleTimeout)
case <-c.Request().Context().Done():
// connection is closed
api.app.Logger().Debug(
"Realtime connection closed (cancelled request)",
slog.String("clientId", client.Id()),
)
return nil
}
}
}
// note: in case of reconnect, clients will have to resubmit all subscriptions again
func (api *realtimeApi) setSubscriptions(c echo.Context) error {
form := forms.NewRealtimeSubscribe()
// read request data
if err := c.Bind(form); err != nil {
return NewBadRequestError("", err)
}
// validate request data
if err := form.Validate(); err != nil {
return NewBadRequestError("", err)
}
// find subscription client
client, err := api.app.SubscriptionsBroker().ClientById(form.ClientId)
if err != nil {
return NewNotFoundError("Missing or invalid client id.", err)
}
// check if the previous request was authorized
oldAuthId := extractAuthIdFromGetter(client)
newAuthId := extractAuthIdFromGetter(c)
if oldAuthId != "" && oldAuthId != newAuthId {
return NewForbiddenError("The current and the previous request authorization don't match.", nil)
}
event := &core.RealtimeSubscribeEvent{
HttpContext: c,
Client: client,
Subscriptions: form.Subscriptions,
}
return api.app.OnRealtimeBeforeSubscribeRequest().Trigger(event, func(e *core.RealtimeSubscribeEvent) error {
// update auth state
e.Client.Set(ContextAdminKey, e.HttpContext.Get(ContextAdminKey))
e.Client.Set(ContextAuthRecordKey, e.HttpContext.Get(ContextAuthRecordKey))
// unsubscribe from any previous existing subscriptions
e.Client.Unsubscribe()
// subscribe to the new subscriptions
e.Client.Subscribe(e.Subscriptions...)
api.app.Logger().Debug(
"Realtime subscriptions updated.",
slog.String("clientId", e.Client.Id()),
slog.Any("subscriptions", e.Subscriptions),
)
return api.app.OnRealtimeAfterSubscribeRequest().Trigger(event, func(e *core.RealtimeSubscribeEvent) error {
if e.HttpContext.Response().Committed {
return nil
}
return e.HttpContext.NoContent(http.StatusNoContent)
})
})
}
// updateClientsAuthModel updates the existing clients auth model with the new one (matched by ID).
func (api *realtimeApi) updateClientsAuthModel(contextKey string, newModel models.Model) error {
for _, client := range api.app.SubscriptionsBroker().Clients() {
clientModel, _ := client.Get(contextKey).(models.Model)
if clientModel != nil &&
clientModel.TableName() == newModel.TableName() &&
clientModel.GetId() == newModel.GetId() {
client.Set(contextKey, newModel)
}
}
return nil
}
// unregisterClientsByAuthModel unregister all clients that has the provided auth model.
func (api *realtimeApi) unregisterClientsByAuthModel(contextKey string, model models.Model) error {
for _, client := range api.app.SubscriptionsBroker().Clients() {
clientModel, _ := client.Get(contextKey).(models.Model)
if clientModel != nil &&
clientModel.TableName() == model.TableName() &&
clientModel.GetId() == model.GetId() {
api.app.SubscriptionsBroker().Unregister(client.Id())
}
}
return nil
}
func (api *realtimeApi) bindEvents() {
// update the clients that has admin or auth record association
api.app.OnModelAfterUpdate().PreAdd(func(e *core.ModelEvent) error {
if record := api.resolveRecord(e.Model); record != nil && record.Collection().IsAuth() {
return api.updateClientsAuthModel(ContextAuthRecordKey, record)
}
if admin, ok := e.Model.(*models.Admin); ok && admin != nil {
return api.updateClientsAuthModel(ContextAdminKey, admin)
}
return nil
})
// remove the client(s) associated to the deleted admin or auth record
api.app.OnModelAfterDelete().PreAdd(func(e *core.ModelEvent) error {
if collection := api.resolveRecordCollection(e.Model); collection != nil && collection.IsAuth() {
return api.unregisterClientsByAuthModel(ContextAuthRecordKey, e.Model)
}
if admin, ok := e.Model.(*models.Admin); ok && admin != nil {
return api.unregisterClientsByAuthModel(ContextAdminKey, admin)
}
return nil
})
api.app.OnModelAfterCreate().PreAdd(func(e *core.ModelEvent) error {
if record := api.resolveRecord(e.Model); record != nil {
if err := api.broadcastRecord("create", record, false); err != nil {
api.app.Logger().Debug(
"Failed to broadcast record create",
slog.String("id", record.Id),
slog.String("collectionName", record.Collection().Name),
slog.String("error", err.Error()),
)
}
}
return nil
})
api.app.OnModelAfterUpdate().PreAdd(func(e *core.ModelEvent) error {
if record := api.resolveRecord(e.Model); record != nil {
if err := api.broadcastRecord("update", record, false); err != nil {
api.app.Logger().Debug(
"Failed to broadcast record update",
slog.String("id", record.Id),
slog.String("collectionName", record.Collection().Name),
slog.String("error", err.Error()),
)
}
}
return nil
})
api.app.OnModelBeforeDelete().Add(func(e *core.ModelEvent) error {
if record := api.resolveRecord(e.Model); record != nil {
if err := api.broadcastRecord("delete", record, true); err != nil {
api.app.Logger().Debug(
"Failed to dry cache record delete",
slog.String("id", record.Id),
slog.String("collectionName", record.Collection().Name),
slog.String("error", err.Error()),
)
}
}
return nil
})
api.app.OnModelAfterDelete().Add(func(e *core.ModelEvent) error {
if record := api.resolveRecord(e.Model); record != nil {
if err := api.broadcastDryCachedRecord("delete", record); err != nil {
api.app.Logger().Debug(
"Failed to broadcast record delete",
slog.String("id", record.Id),
slog.String("collectionName", record.Collection().Name),
slog.String("error", err.Error()),
)
}
}
return nil
})
}
// resolveRecord converts *if possible* the provided model interface to a Record.
// This is usually helpful if the provided model is a custom Record model struct.
func (api *realtimeApi) resolveRecord(model models.Model) (record *models.Record) {
record, _ = model.(*models.Record)
// check if it is custom Record model struct (ignore "private" tables)
if record == nil && !strings.HasPrefix(model.TableName(), "_") {
record, _ = api.app.Dao().FindRecordById(model.TableName(), model.GetId())
}
return record
}
// resolveRecordCollection extracts *if possible* the Collection model from the provided model interface.
// This is usually helpful if the provided model is a custom Record model struct.
func (api *realtimeApi) resolveRecordCollection(model models.Model) (collection *models.Collection) {
if record, ok := model.(*models.Record); ok {
collection = record.Collection()
} else if !strings.HasPrefix(model.TableName(), "_") {
// check if it is custom Record model struct (ignore "private" tables)
collection, _ = api.app.Dao().FindCollectionByNameOrId(model.TableName())
}
return collection
}
// recordData represents the broadcasted record subscrition message data.
type recordData struct {
Record any `json:"record"` /* map or models.Record */
Action string `json:"action"`
}
func (api *realtimeApi) broadcastRecord(action string, record *models.Record, dryCache bool) error {
collection := record.Collection()
if collection == nil {
return errors.New("[broadcastRecord] Record collection not set.")
}
clients := api.app.SubscriptionsBroker().Clients()
if len(clients) == 0 {
return nil // no subscribers
}
subscriptionRuleMap := map[string]*string{
(collection.Name + "/" + record.Id + "?"): collection.ViewRule,
(collection.Id + "/" + record.Id + "?"): collection.ViewRule,
(collection.Name + "/*?"): collection.ListRule,
(collection.Id + "/*?"): collection.ListRule,
// @deprecated: the same as the wildcard topic but kept for backward compatibility
(collection.Name + "?"): collection.ListRule,
(collection.Id + "?"): collection.ListRule,
}
dryCacheKey := action + "/" + record.Id
for _, client := range clients {
client := client
// note: not executed concurrently to avoid races and to ensure
// that the access checks are applied for the current record db state
for prefix, rule := range subscriptionRuleMap {
subs := client.Subscriptions(prefix)
if len(subs) == 0 {
continue
}
for sub, options := range subs {
// create a clean record copy without expand and unknown fields
// because we don't know yet which exact fields the client subscription has permissions to access
cleanRecord := record.CleanCopy()
// mock request data
requestInfo := &models.RequestInfo{
Context: models.RequestInfoContextRealtime,
Method: "GET",
Query: options.Query,
Headers: options.Headers,
}
requestInfo.Admin, _ = client.Get(ContextAdminKey).(*models.Admin)
requestInfo.AuthRecord, _ = client.Get(ContextAuthRecordKey).(*models.Record)
if !api.canAccessRecord(cleanRecord, requestInfo, rule) {
continue
}
rawExpand := cast.ToString(options.Query[expandQueryParam])
if rawExpand != "" {
expandErrs := api.app.Dao().ExpandRecord(cleanRecord, strings.Split(rawExpand, ","), expandFetch(api.app.Dao(), requestInfo))
if len(expandErrs) > 0 {
api.app.Logger().Debug(
"[broadcastRecord] expand errors",
slog.String("id", cleanRecord.Id),
slog.String("collectionName", cleanRecord.Collection().Name),
slog.String("sub", sub),
slog.String("expand", rawExpand),
slog.Any("errors", expandErrs),
)
}
}
// ignore the auth record email visibility checks
// for auth owner, admin or manager
if collection.IsAuth() {
authId := extractAuthIdFromGetter(client)
if authId == cleanRecord.Id {
if api.canAccessRecord(cleanRecord, requestInfo, collection.AuthOptions().ManageRule) {
cleanRecord.IgnoreEmailVisibility(true)
}
}
}
data := &recordData{
Action: action,
Record: cleanRecord,
}
// check fields
rawFields := cast.ToString(options.Query[fieldsQueryParam])
if rawFields != "" {
decoded, err := rest.PickFields(cleanRecord, rawFields)
if err == nil {
data.Record = decoded
} else {
api.app.Logger().Debug(
"[broadcastRecord] pick fields error",
slog.String("id", cleanRecord.Id),
slog.String("collectionName", cleanRecord.Collection().Name),
slog.String("sub", sub),
slog.String("fields", rawFields),
slog.String("error", err.Error()),
)
}
}
dataBytes, err := json.Marshal(data)
if err != nil {
api.app.Logger().Debug(
"[broadcastRecord] data marshal error",
slog.String("id", cleanRecord.Id),
slog.String("collectionName", cleanRecord.Collection().Name),
slog.String("error", err.Error()),
)
continue
}
msg := subscriptions.Message{
Name: sub,
Data: dataBytes,
}
if dryCache {
messages, ok := client.Get(dryCacheKey).([]subscriptions.Message)
if !ok {
messages = []subscriptions.Message{msg}
} else {
messages = append(messages, msg)
}
client.Set(dryCacheKey, messages)
} else {
routine.FireAndForget(func() {
client.Send(msg)
})
}
}
}
}
return nil
}
// broadcastDryCachedRecord broadcasts all cached record related messages.
func (api *realtimeApi) broadcastDryCachedRecord(action string, record *models.Record) error {
key := action + "/" + record.Id
clients := api.app.SubscriptionsBroker().Clients()
for _, client := range clients {
messages, ok := client.Get(key).([]subscriptions.Message)
if !ok {
continue
}
client.Unset(key)
client := client
routine.FireAndForget(func() {
for _, msg := range messages {
client.Send(msg)
}
})
}
return nil
}
type getter interface {
Get(string) any
}
func extractAuthIdFromGetter(val getter) string {
record, _ := val.Get(ContextAuthRecordKey).(*models.Record)
if record != nil {
return record.Id
}
admin, _ := val.Get(ContextAdminKey).(*models.Admin)
if admin != nil {
return admin.Id
}
return ""
}
// canAccessRecord checks if the subscription client has access to the specified record model.
func (api *realtimeApi) canAccessRecord(
record *models.Record,
requestInfo *models.RequestInfo,
accessRule *string,
) bool {
// check the access rule
// ---
if ok, _ := api.app.Dao().CanAccessRecord(record, requestInfo, accessRule); !ok {
return false
}
// check the subscription client-side filter (if any)
// ---
filter := cast.ToString(requestInfo.Query[search.FilterQueryParam])
if filter == "" {
return true // no further checks needed
}
if err := checkForAdminOnlyRuleFields(requestInfo); err != nil {
return false
}
ruleFunc := func(q *dbx.SelectQuery) error {
resolver := resolvers.NewRecordFieldResolver(api.app.Dao(), record.Collection(), requestInfo, false)
expr, err := search.FilterData(filter).BuildExpr(resolver)
if err != nil {
return err
}
q.AndWhere(expr)
resolver.UpdateQuery(q)
return nil
}
_, err := api.app.Dao().FindRecordById(record.Collection().Id, record.Id, ruleFunc)
return err == nil
}