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ntfy/server/server.go
Philipp Heckel d6762276f5 Test
2021-12-25 22:07:55 +01:00

826 lines
25 KiB
Go

package server
import (
"bytes"
"context"
"embed"
"encoding/json"
firebase "firebase.google.com/go"
"firebase.google.com/go/messaging"
"fmt"
"google.golang.org/api/option"
"heckel.io/ntfy/util"
"html/template"
"io"
"log"
"net"
"net/http"
"regexp"
"strconv"
"strings"
"sync"
"time"
)
// TODO add "max messages in a topic" limit
// TODO implement "since=<ID>"
// Server is the main server, providing the UI and API for ntfy
type Server struct {
config *Config
httpServer *http.Server
httpsServer *http.Server
topics map[string]*topic
visitors map[string]*visitor
firebase subscriber
mailer mailer
messages int64
cache cache
closeChan chan bool
mu sync.Mutex
}
// errHTTP is a generic HTTP error for any non-200 HTTP error
type errHTTP struct {
Code int `json:"code,omitempty"`
HTTPCode int `json:"http"`
Message string `json:"error"`
Link string `json:"link,omitempty"`
}
func (e errHTTP) Error() string {
return e.Message
}
func (e errHTTP) JSON() string {
b, _ := json.Marshal(&e)
return string(b)
}
type indexPage struct {
Topic string
CacheDuration time.Duration
}
type sinceTime time.Time
func (t sinceTime) IsAll() bool {
return t == sinceAllMessages
}
func (t sinceTime) IsNone() bool {
return t == sinceNoMessages
}
func (t sinceTime) Time() time.Time {
return time.Time(t)
}
var (
sinceAllMessages = sinceTime(time.Unix(0, 0))
sinceNoMessages = sinceTime(time.Unix(1, 0))
)
var (
topicRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`) // Regex must match JS & Android app!
jsonRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`)
sseRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/sse$`)
rawRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/raw$`)
sendRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/(publish|send|trigger)$`)
staticRegex = regexp.MustCompile(`^/static/.+`)
docsRegex = regexp.MustCompile(`^/docs(|/.*)$`)
disallowedTopics = []string{"docs", "static"}
templateFnMap = template.FuncMap{
"durationToHuman": util.DurationToHuman,
}
//go:embed "index.gohtml"
indexSource string
indexTemplate = template.Must(template.New("index").Funcs(templateFnMap).Parse(indexSource))
//go:embed "example.html"
exampleSource string
//go:embed static
webStaticFs embed.FS
webStaticFsCached = &util.CachingEmbedFS{ModTime: time.Now(), FS: webStaticFs}
//go:embed docs
docsStaticFs embed.FS
docsStaticCached = &util.CachingEmbedFS{ModTime: time.Now(), FS: docsStaticFs}
errHTTPNotFound = &errHTTP{40401, http.StatusNotFound, "page not found", ""}
errHTTPTooManyRequestsLimitRequests = &errHTTP{42901, http.StatusTooManyRequests, "limit reached: too many requests, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
errHTTPTooManyRequestsLimitEmails = &errHTTP{42902, http.StatusTooManyRequests, "limit reached: too many emails, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
errHTTPTooManyRequestsLimitSubscriptions = &errHTTP{42903, http.StatusTooManyRequests, "limit reached: too many active subscriptions, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
errHTTPTooManyRequestsLimitGlobalTopics = &errHTTP{42904, http.StatusTooManyRequests, "limit reached: the total number of topics on the server has been reached, please contact the admin", "https://ntfy.sh/docs/publish/#limitations"}
errHTTPBadRequestEmailDisabled = &errHTTP{40001, http.StatusBadRequest, "e-mail notifications are not enabled", "https://ntfy.sh/docs/config/#e-mail-notifications"}
errHTTPBadRequestDelayNoCache = &errHTTP{40002, http.StatusBadRequest, "cannot disable cache for delayed message", ""}
errHTTPBadRequestDelayNoEmail = &errHTTP{40003, http.StatusBadRequest, "delayed e-mail notifications are not supported", ""}
errHTTPBadRequestDelayCannotParse = &errHTTP{40004, http.StatusBadRequest, "invalid delay parameter: unable to parse delay", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
errHTTPBadRequestDelayTooSmall = &errHTTP{40005, http.StatusBadRequest, "invalid delay parameter: too small, please refer to the docs", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
errHTTPBadRequestDelayTooLarge = &errHTTP{40006, http.StatusBadRequest, "invalid delay parameter: too large, please refer to the docs", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
errHTTPBadRequestPriorityInvalid = &errHTTP{40007, http.StatusBadRequest, "invalid priority parameter", "https://ntfy.sh/docs/publish/#message-priority"}
errHTTPBadRequestSinceInvalid = &errHTTP{40008, http.StatusBadRequest, "invalid since parameter", "https://ntfy.sh/docs/subscribe/api/#fetch-cached-messages"}
errHTTPBadRequestTopicInvalid = &errHTTP{40009, http.StatusBadRequest, "invalid topic: path invalid", ""}
errHTTPBadRequestTopicDisallowed = &errHTTP{40010, http.StatusBadRequest, "invalid topic: topic name is disallowed", ""}
errHTTPInternalError = &errHTTP{50001, http.StatusInternalServerError, "internal server error", ""}
)
const (
firebaseControlTopic = "~control" // See Android if changed
emptyMessageBody = "triggered"
)
// New instantiates a new Server. It creates the cache and adds a Firebase
// subscriber (if configured).
func New(conf *Config) (*Server, error) {
var firebaseSubscriber subscriber
if conf.FirebaseKeyFile != "" {
var err error
firebaseSubscriber, err = createFirebaseSubscriber(conf)
if err != nil {
return nil, err
}
}
var mailer mailer
if conf.SMTPAddr != "" {
mailer = &smtpMailer{config: conf}
}
cache, err := createCache(conf)
if err != nil {
return nil, err
}
topics, err := cache.Topics()
if err != nil {
return nil, err
}
return &Server{
config: conf,
cache: cache,
firebase: firebaseSubscriber,
mailer: mailer,
topics: topics,
visitors: make(map[string]*visitor),
}, nil
}
func createCache(conf *Config) (cache, error) {
if conf.CacheDuration == 0 {
return newNopCache(), nil
} else if conf.CacheFile != "" {
return newSqliteCache(conf.CacheFile)
}
return newMemCache(), nil
}
func createFirebaseSubscriber(conf *Config) (subscriber, error) {
fb, err := firebase.NewApp(context.Background(), nil, option.WithCredentialsFile(conf.FirebaseKeyFile))
if err != nil {
return nil, err
}
msg, err := fb.Messaging(context.Background())
if err != nil {
return nil, err
}
return func(m *message) error {
var data map[string]string // Matches https://ntfy.sh/docs/subscribe/api/#json-message-format
switch m.Event {
case keepaliveEvent, openEvent:
data = map[string]string{
"id": m.ID,
"time": fmt.Sprintf("%d", m.Time),
"event": m.Event,
"topic": m.Topic,
}
case messageEvent:
data = map[string]string{
"id": m.ID,
"time": fmt.Sprintf("%d", m.Time),
"event": m.Event,
"topic": m.Topic,
"priority": fmt.Sprintf("%d", m.Priority),
"tags": strings.Join(m.Tags, ","),
"title": m.Title,
"message": m.Message,
}
}
_, err := msg.Send(context.Background(), &messaging.Message{
Topic: m.Topic,
Data: data,
})
return err
}, nil
}
// Run executes the main server. It listens on HTTP (+ HTTPS, if configured), and starts
// a manager go routine to print stats and prune messages.
func (s *Server) Run() error {
listenStr := fmt.Sprintf("%s/http", s.config.ListenHTTP)
if s.config.ListenHTTPS != "" {
listenStr += fmt.Sprintf(" %s/https", s.config.ListenHTTPS)
}
log.Printf("Listening on %s", listenStr)
mux := http.NewServeMux()
mux.HandleFunc("/", s.handle)
errChan := make(chan error)
s.mu.Lock()
s.closeChan = make(chan bool)
s.httpServer = &http.Server{Addr: s.config.ListenHTTP, Handler: mux}
go func() {
errChan <- s.httpServer.ListenAndServe()
}()
if s.config.ListenHTTPS != "" {
s.httpsServer = &http.Server{Addr: s.config.ListenHTTP, Handler: mux}
go func() {
errChan <- s.httpsServer.ListenAndServeTLS(s.config.CertFile, s.config.KeyFile)
}()
}
s.mu.Unlock()
go s.runManager()
go s.runAtSender()
go s.runFirebaseKeepliver()
return <-errChan
}
// Stop stops HTTP (+HTTPS) server and all managers
func (s *Server) Stop() {
s.mu.Lock()
defer s.mu.Unlock()
if s.httpServer != nil {
s.httpServer.Close()
}
if s.httpsServer != nil {
s.httpsServer.Close()
}
close(s.closeChan)
}
func (s *Server) handle(w http.ResponseWriter, r *http.Request) {
if err := s.handleInternal(w, r); err != nil {
var e *errHTTP
var ok bool
if e, ok = err.(*errHTTP); !ok {
e = errHTTPInternalError
}
log.Printf("[%s] %s - %d - %s", r.RemoteAddr, r.Method, e.HTTPCode, err.Error())
w.Header().Set("Content-Type", "application/json")
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
w.WriteHeader(e.HTTPCode)
io.WriteString(w, e.JSON()+"\n")
}
}
func (s *Server) handleInternal(w http.ResponseWriter, r *http.Request) error {
if r.Method == http.MethodGet && r.URL.Path == "/" {
return s.handleHome(w, r)
} else if r.Method == http.MethodGet && r.URL.Path == "/example.html" {
return s.handleExample(w, r)
} else if r.Method == http.MethodHead && r.URL.Path == "/" {
return s.handleEmpty(w, r)
} else if r.Method == http.MethodGet && staticRegex.MatchString(r.URL.Path) {
return s.handleStatic(w, r)
} else if r.Method == http.MethodGet && docsRegex.MatchString(r.URL.Path) {
return s.handleDocs(w, r)
} else if r.Method == http.MethodOptions {
return s.handleOptions(w, r)
} else if r.Method == http.MethodGet && topicRegex.MatchString(r.URL.Path) {
return s.handleTopic(w, r)
} else if (r.Method == http.MethodPut || r.Method == http.MethodPost) && topicRegex.MatchString(r.URL.Path) {
return s.withRateLimit(w, r, s.handlePublish)
} else if r.Method == http.MethodGet && sendRegex.MatchString(r.URL.Path) {
return s.withRateLimit(w, r, s.handlePublish)
} else if r.Method == http.MethodGet && jsonRegex.MatchString(r.URL.Path) {
return s.withRateLimit(w, r, s.handleSubscribeJSON)
} else if r.Method == http.MethodGet && sseRegex.MatchString(r.URL.Path) {
return s.withRateLimit(w, r, s.handleSubscribeSSE)
} else if r.Method == http.MethodGet && rawRegex.MatchString(r.URL.Path) {
return s.withRateLimit(w, r, s.handleSubscribeRaw)
}
return errHTTPNotFound
}
func (s *Server) handleHome(w http.ResponseWriter, r *http.Request) error {
return indexTemplate.Execute(w, &indexPage{
Topic: r.URL.Path[1:],
CacheDuration: s.config.CacheDuration,
})
}
func (s *Server) handleTopic(w http.ResponseWriter, r *http.Request) error {
unifiedpush := readParam(r, "x-unifiedpush", "unifiedpush", "up") == "1" // see PUT/POST too!
if unifiedpush {
w.Header().Set("Content-Type", "application/json")
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
_, err := io.WriteString(w, `{"unifiedpush":{"version":1}}`+"\n")
return err
}
return s.handleHome(w, r)
}
func (s *Server) handleEmpty(_ http.ResponseWriter, _ *http.Request) error {
return nil
}
func (s *Server) handleExample(w http.ResponseWriter, _ *http.Request) error {
_, err := io.WriteString(w, exampleSource)
return err
}
func (s *Server) handleStatic(w http.ResponseWriter, r *http.Request) error {
http.FileServer(http.FS(webStaticFsCached)).ServeHTTP(w, r)
return nil
}
func (s *Server) handleDocs(w http.ResponseWriter, r *http.Request) error {
http.FileServer(http.FS(docsStaticCached)).ServeHTTP(w, r)
return nil
}
func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visitor) error {
t, err := s.topicFromPath(r.URL.Path)
if err != nil {
return err
}
reader := io.LimitReader(r.Body, int64(s.config.MessageLimit))
b, err := io.ReadAll(reader)
if err != nil {
return err
}
m := newDefaultMessage(t.ID, strings.TrimSpace(string(b)))
cache, firebase, email, err := s.parsePublishParams(r, m)
if err != nil {
return err
}
if email != "" {
if err := v.EmailAllowed(); err != nil {
return errHTTPTooManyRequestsLimitEmails
}
}
if s.mailer == nil && email != "" {
return errHTTPBadRequestEmailDisabled
}
if m.Message == "" {
m.Message = emptyMessageBody
}
delayed := m.Time > time.Now().Unix()
if !delayed {
if err := t.Publish(m); err != nil {
return err
}
}
if s.firebase != nil && firebase && !delayed {
go func() {
if err := s.firebase(m); err != nil {
log.Printf("Unable to publish to Firebase: %v", err.Error())
}
}()
}
if s.mailer != nil && email != "" && !delayed {
go func() {
if err := s.mailer.Send(v.ip, email, m); err != nil {
log.Printf("Unable to send email: %v", err.Error())
}
}()
}
if cache {
if err := s.cache.AddMessage(m); err != nil {
return err
}
}
w.Header().Set("Content-Type", "application/json")
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
if err := json.NewEncoder(w).Encode(m); err != nil {
return err
}
s.inc(&s.messages)
return nil
}
func (s *Server) parsePublishParams(r *http.Request, m *message) (cache bool, firebase bool, email string, err error) {
cache = readParam(r, "x-cache", "cache") != "no"
firebase = readParam(r, "x-firebase", "firebase") != "no"
email = readParam(r, "x-email", "x-e-mail", "email", "e-mail", "mail", "e")
m.Title = readParam(r, "x-title", "title", "t")
messageStr := readParam(r, "x-message", "message", "m")
if messageStr != "" {
m.Message = messageStr
}
m.Priority, err = util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p"))
if err != nil {
return false, false, "", errHTTPBadRequestPriorityInvalid
}
tagsStr := readParam(r, "x-tags", "tags", "tag", "ta")
if tagsStr != "" {
m.Tags = make([]string, 0)
for _, s := range util.SplitNoEmpty(tagsStr, ",") {
m.Tags = append(m.Tags, strings.TrimSpace(s))
}
}
delayStr := readParam(r, "x-delay", "delay", "x-at", "at", "x-in", "in")
if delayStr != "" {
if !cache {
return false, false, "", errHTTPBadRequestDelayNoCache
}
if email != "" {
return false, false, "", errHTTPBadRequestDelayNoEmail // we cannot store the email address (yet)
}
delay, err := util.ParseFutureTime(delayStr, time.Now())
if err != nil {
return false, false, "", errHTTPBadRequestDelayCannotParse
} else if delay.Unix() < time.Now().Add(s.config.MinDelay).Unix() {
return false, false, "", errHTTPBadRequestDelayTooSmall
} else if delay.Unix() > time.Now().Add(s.config.MaxDelay).Unix() {
return false, false, "", errHTTPBadRequestDelayTooLarge
}
m.Time = delay.Unix()
}
unifiedpush := readParam(r, "x-unifiedpush", "unifiedpush", "up") == "1" // see GET too!
if unifiedpush {
firebase = false
}
return cache, firebase, email, nil
}
func readParam(r *http.Request, names ...string) string {
for _, name := range names {
value := r.Header.Get(name)
if value != "" {
return strings.TrimSpace(value)
}
}
for _, name := range names {
value := r.URL.Query().Get(strings.ToLower(name))
if value != "" {
return strings.TrimSpace(value)
}
}
return ""
}
func (s *Server) handleSubscribeJSON(w http.ResponseWriter, r *http.Request, v *visitor) error {
encoder := func(msg *message) (string, error) {
var buf bytes.Buffer
if err := json.NewEncoder(&buf).Encode(&msg); err != nil {
return "", err
}
return buf.String(), nil
}
return s.handleSubscribe(w, r, v, "json", "application/x-ndjson", encoder)
}
func (s *Server) handleSubscribeSSE(w http.ResponseWriter, r *http.Request, v *visitor) error {
encoder := func(msg *message) (string, error) {
var buf bytes.Buffer
if err := json.NewEncoder(&buf).Encode(&msg); err != nil {
return "", err
}
if msg.Event != messageEvent {
return fmt.Sprintf("event: %s\ndata: %s\n", msg.Event, buf.String()), nil // Browser's .onmessage() does not fire on this!
}
return fmt.Sprintf("data: %s\n", buf.String()), nil
}
return s.handleSubscribe(w, r, v, "sse", "text/event-stream", encoder)
}
func (s *Server) handleSubscribeRaw(w http.ResponseWriter, r *http.Request, v *visitor) error {
encoder := func(msg *message) (string, error) {
if msg.Event == messageEvent { // only handle default events
return strings.ReplaceAll(msg.Message, "\n", " ") + "\n", nil
}
return "\n", nil // "keepalive" and "open" events just send an empty line
}
return s.handleSubscribe(w, r, v, "raw", "text/plain", encoder)
}
func (s *Server) handleSubscribe(w http.ResponseWriter, r *http.Request, v *visitor, format string, contentType string, encoder messageEncoder) error {
if err := v.SubscriptionAllowed(); err != nil {
return errHTTPTooManyRequestsLimitSubscriptions
}
defer v.RemoveSubscription()
topicsStr := strings.TrimSuffix(r.URL.Path[1:], "/"+format) // Hack
topicIDs := util.SplitNoEmpty(topicsStr, ",")
topics, err := s.topicsFromIDs(topicIDs...)
if err != nil {
return err
}
poll := readParam(r, "x-poll", "poll", "po") == "1"
scheduled := readParam(r, "x-scheduled", "scheduled", "sched") == "1"
since, err := parseSince(r, poll)
if err != nil {
return err
}
messageFilter, titleFilter, priorityFilter, tagsFilter, err := parseQueryFilters(r)
if err != nil {
return err
}
var wlock sync.Mutex
sub := func(msg *message) error {
if !passesQueryFilter(msg, messageFilter, titleFilter, priorityFilter, tagsFilter) {
return nil
}
m, err := encoder(msg)
if err != nil {
return err
}
wlock.Lock()
defer wlock.Unlock()
if _, err := w.Write([]byte(m)); err != nil {
return err
}
if fl, ok := w.(http.Flusher); ok {
fl.Flush()
}
return nil
}
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
w.Header().Set("Content-Type", contentType+"; charset=utf-8") // Android/Volley client needs charset!
if poll {
return s.sendOldMessages(topics, since, scheduled, sub)
}
subscriberIDs := make([]int, 0)
for _, t := range topics {
subscriberIDs = append(subscriberIDs, t.Subscribe(sub))
}
defer func() {
for i, subscriberID := range subscriberIDs {
topics[i].Unsubscribe(subscriberID) // Order!
}
}()
if err := sub(newOpenMessage(topicsStr)); err != nil { // Send out open message
return err
}
if err := s.sendOldMessages(topics, since, scheduled, sub); err != nil {
return err
}
for {
select {
case <-r.Context().Done():
return nil
case <-time.After(s.config.KeepaliveInterval):
v.Keepalive()
if err := sub(newKeepaliveMessage(topicsStr)); err != nil { // Send keepalive message
return err
}
}
}
}
func parseQueryFilters(r *http.Request) (messageFilter string, titleFilter string, priorityFilter []int, tagsFilter []string, err error) {
messageFilter = readParam(r, "x-message", "message", "m")
titleFilter = readParam(r, "x-title", "title", "t")
tagsFilter = util.SplitNoEmpty(readParam(r, "x-tags", "tags", "tag", "ta"), ",")
priorityFilter = make([]int, 0)
for _, p := range util.SplitNoEmpty(readParam(r, "x-priority", "priority", "prio", "p"), ",") {
priority, err := util.ParsePriority(p)
if err != nil {
return "", "", nil, nil, err
}
priorityFilter = append(priorityFilter, priority)
}
return
}
func passesQueryFilter(msg *message, messageFilter string, titleFilter string, priorityFilter []int, tagsFilter []string) bool {
if msg.Event != messageEvent {
return true // filters only apply to messages
}
if messageFilter != "" && msg.Message != messageFilter {
return false
}
if titleFilter != "" && msg.Title != titleFilter {
return false
}
messagePriority := msg.Priority
if messagePriority == 0 {
messagePriority = 3 // For query filters, default priority (3) is the same as "not set" (0)
}
if len(priorityFilter) > 0 && !util.InIntList(priorityFilter, messagePriority) {
return false
}
if len(tagsFilter) > 0 && !util.InStringListAll(msg.Tags, tagsFilter) {
return false
}
return true
}
func (s *Server) sendOldMessages(topics []*topic, since sinceTime, scheduled bool, sub subscriber) error {
if since.IsNone() {
return nil
}
for _, t := range topics {
messages, err := s.cache.Messages(t.ID, since, scheduled)
if err != nil {
return err
}
for _, m := range messages {
if err := sub(m); err != nil {
return err
}
}
}
return nil
}
// parseSince returns a timestamp identifying the time span from which cached messages should be received.
//
// Values in the "since=..." parameter can be either a unix timestamp or a duration (e.g. 12h), or
// "all" for all messages.
func parseSince(r *http.Request, poll bool) (sinceTime, error) {
since := readParam(r, "x-since", "since", "si")
if since == "" {
if poll {
return sinceAllMessages, nil
}
return sinceNoMessages, nil
}
if since == "all" {
return sinceAllMessages, nil
} else if s, err := strconv.ParseInt(since, 10, 64); err == nil {
return sinceTime(time.Unix(s, 0)), nil
} else if d, err := time.ParseDuration(since); err == nil {
return sinceTime(time.Now().Add(-1 * d)), nil
}
return sinceNoMessages, errHTTPBadRequestSinceInvalid
}
func (s *Server) handleOptions(w http.ResponseWriter, _ *http.Request) error {
w.Header().Set("Access-Control-Allow-Origin", "*") // CORS, allow cross-origin requests
w.Header().Set("Access-Control-Allow-Methods", "GET, PUT, POST")
return nil
}
func (s *Server) topicFromPath(path string) (*topic, error) {
parts := strings.Split(path, "/")
if len(parts) < 2 {
return nil, errHTTPBadRequestTopicInvalid
}
topics, err := s.topicsFromIDs(parts[1])
if err != nil {
return nil, err
}
return topics[0], nil
}
func (s *Server) topicsFromIDs(ids ...string) ([]*topic, error) {
s.mu.Lock()
defer s.mu.Unlock()
topics := make([]*topic, 0)
for _, id := range ids {
if util.InStringList(disallowedTopics, id) {
return nil, errHTTPBadRequestTopicDisallowed
}
if _, ok := s.topics[id]; !ok {
if len(s.topics) >= s.config.GlobalTopicLimit {
return nil, errHTTPTooManyRequestsLimitGlobalTopics
}
s.topics[id] = newTopic(id)
}
topics = append(topics, s.topics[id])
}
return topics, nil
}
func (s *Server) updateStatsAndPrune() {
s.mu.Lock()
defer s.mu.Unlock()
// Expire visitors from rate visitors map
for ip, v := range s.visitors {
if v.Stale() {
delete(s.visitors, ip)
}
}
// Prune message cache
olderThan := time.Now().Add(-1 * s.config.CacheDuration)
if err := s.cache.Prune(olderThan); err != nil {
log.Printf("error pruning cache: %s", err.Error())
}
// Prune old topics, remove subscriptions without subscribers
var subscribers, messages int
for _, t := range s.topics {
subs := t.Subscribers()
msgs, err := s.cache.MessageCount(t.ID)
if err != nil {
log.Printf("cannot get stats for topic %s: %s", t.ID, err.Error())
continue
}
if msgs == 0 && subs == 0 {
delete(s.topics, t.ID)
continue
}
subscribers += subs
messages += msgs
}
// Print stats
log.Printf("Stats: %d message(s) published, %d topic(s) active, %d subscriber(s), %d message(s) buffered, %d visitor(s)",
s.messages, len(s.topics), subscribers, messages, len(s.visitors))
}
func (s *Server) runManager() {
for {
select {
case <-time.After(s.config.ManagerInterval):
s.updateStatsAndPrune()
case <-s.closeChan:
return
}
}
}
func (s *Server) runAtSender() {
for {
select {
case <-time.After(s.config.AtSenderInterval):
if err := s.sendDelayedMessages(); err != nil {
log.Printf("error sending scheduled messages: %s", err.Error())
}
case <-s.closeChan:
return
}
}
}
func (s *Server) runFirebaseKeepliver() {
if s.firebase == nil {
return
}
for {
select {
case <-time.After(s.config.FirebaseKeepaliveInterval):
if err := s.firebase(newKeepaliveMessage(firebaseControlTopic)); err != nil {
log.Printf("error sending Firebase keepalive message: %s", err.Error())
}
case <-s.closeChan:
return
}
}
}
func (s *Server) sendDelayedMessages() error {
s.mu.Lock()
defer s.mu.Unlock()
messages, err := s.cache.MessagesDue()
if err != nil {
return err
}
for _, m := range messages {
t, ok := s.topics[m.Topic] // If no subscribers, just mark message as published
if ok {
if err := t.Publish(m); err != nil {
log.Printf("unable to publish message %s to topic %s: %v", m.ID, m.Topic, err.Error())
}
if s.firebase != nil {
if err := s.firebase(m); err != nil {
log.Printf("unable to publish to Firebase: %v", err.Error())
}
}
// TODO delayed email sending
}
if err := s.cache.MarkPublished(m); err != nil {
return err
}
}
return nil
}
func (s *Server) withRateLimit(w http.ResponseWriter, r *http.Request, handler func(w http.ResponseWriter, r *http.Request, v *visitor) error) error {
v := s.visitor(r)
if err := v.RequestAllowed(); err != nil {
return errHTTPTooManyRequestsLimitRequests
}
return handler(w, r, v)
}
// visitor creates or retrieves a rate.Limiter for the given visitor.
// This function was taken from https://www.alexedwards.net/blog/how-to-rate-limit-http-requests (MIT).
func (s *Server) visitor(r *http.Request) *visitor {
s.mu.Lock()
defer s.mu.Unlock()
remoteAddr := r.RemoteAddr
ip, _, err := net.SplitHostPort(remoteAddr)
if err != nil {
ip = remoteAddr // This should not happen in real life; only in tests.
}
if s.config.BehindProxy && r.Header.Get("X-Forwarded-For") != "" {
ip = r.Header.Get("X-Forwarded-For")
}
v, exists := s.visitors[ip]
if !exists {
s.visitors[ip] = newVisitor(s.config, ip)
return s.visitors[ip]
}
v.Keepalive()
return v
}
func (s *Server) inc(counter *int64) {
s.mu.Lock()
defer s.mu.Unlock()
*counter++
}