Backend image rendering as plugin (#11966)

* rendering: headless chrome progress

* renderer: minor change

* grpc: version hell

* updated grpc libs

* wip: minor progess

* rendering: new image rendering plugin is starting to work

* feat: now phantomjs works as well and updated alerting to use new rendering service

* refactor: renamed renderer package and service to rendering to make renderer name less confusing (rendering is internal service that handles the renderer plugin now)

* rendering: now render key is passed and render auth is working in plugin mode

* removed unneeded lines from gitignore

* rendering: now plugin mode supports waiting for all panels to complete rendering

* fix: LastSeenAt fix for render calls, was not set which causes a lot of updates to Last Seen at during rendering, this should fix sqlite db locked issues in seen in previous releases

* change: changed render tz url parameter to use proper timezone name as chrome does not handle UTC offset TZ values

* fix: another update to tz param generation

* renderer: added http mode to renderer service, new ini setting [rendering] server_url

vendor/github.com/hashicorp/yamux/session.go

@@ -329,8 +329,17 @@ func (s *Session) waitForSend(hdr header, body io.Reader) error {
 // potential shutdown. Since there's the expectation that sends can happen
 // in a timely manner, we enforce the connection write timeout here.
 func (s *Session) waitForSendErr(hdr header, body io.Reader, errCh chan error) error {
-	timer := time.NewTimer(s.config.ConnectionWriteTimeout)
-	defer timer.Stop()
+	t := timerPool.Get()
+	timer := t.(*time.Timer)
+	timer.Reset(s.config.ConnectionWriteTimeout)
+	defer func() {
+		timer.Stop()
+		select {
+		case <-timer.C:
+		default:
+		}
+		timerPool.Put(t)
+	}()
 
 	ready := sendReady{Hdr: hdr, Body: body, Err: errCh}
 	select {
@@ -355,8 +364,17 @@ func (s *Session) waitForSendErr(hdr header, body io.Reader, errCh chan error) e
 // the send happens right here, we enforce the connection write timeout if we
 // can't queue the header to be sent.
 func (s *Session) sendNoWait(hdr header) error {
-	timer := time.NewTimer(s.config.ConnectionWriteTimeout)
-	defer timer.Stop()
+	t := timerPool.Get()
+	timer := t.(*time.Timer)
+	timer.Reset(s.config.ConnectionWriteTimeout)
+	defer func() {
+		timer.Stop()
+		select {
+		case <-timer.C:
+		default:
+		}
+		timerPool.Put(t)
+	}()
 
 	select {
 	case s.sendCh <- sendReady{Hdr: hdr}:
@@ -414,11 +432,20 @@ func (s *Session) recv() {
 	}
 }
 
+// Ensure that the index of the handler (typeData/typeWindowUpdate/etc) matches the message type
+var (
+	handlers = []func(*Session, header) error{
+		typeData:         (*Session).handleStreamMessage,
+		typeWindowUpdate: (*Session).handleStreamMessage,
+		typePing:         (*Session).handlePing,
+		typeGoAway:       (*Session).handleGoAway,
+	}
+)
+
 // recvLoop continues to receive data until a fatal error is encountered
 func (s *Session) recvLoop() error {
 	defer close(s.recvDoneCh)
 	hdr := header(make([]byte, headerSize))
-	var handler func(header) error
 	for {
 		// Read the header
 		if _, err := io.ReadFull(s.bufRead, hdr); err != nil {
@@ -434,22 +461,12 @@ func (s *Session) recvLoop() error {
 			return ErrInvalidVersion
 		}
 
-		// Switch on the type
-		switch hdr.MsgType() {
-		case typeData:
-			handler = s.handleStreamMessage
-		case typeWindowUpdate:
-			handler = s.handleStreamMessage
-		case typeGoAway:
-			handler = s.handleGoAway
-		case typePing:
-			handler = s.handlePing
-		default:
+		mt := hdr.MsgType()
+		if mt < typeData || mt > typeGoAway {
 			return ErrInvalidMsgType
 		}
 
-		// Invoke the handler
-		if err := handler(hdr); err != nil {
+		if err := handlers[mt](s, hdr); err != nil {
 			return err
 		}
 	}

vendor/github.com/hashicorp/yamux/stream.go

@@ -242,18 +242,25 @@ func (s *Stream) sendWindowUpdate() error {
 
 	// Determine the delta update
 	max := s.session.config.MaxStreamWindowSize
-	delta := max - atomic.LoadUint32(&s.recvWindow)
+	var bufLen uint32
+	s.recvLock.Lock()
+	if s.recvBuf != nil {
+		bufLen = uint32(s.recvBuf.Len())
+	}
+	delta := (max - bufLen) - s.recvWindow
 
 	// Determine the flags if any
 	flags := s.sendFlags()
 
 	// Check if we can omit the update
 	if delta < (max/2) && flags == 0 {
+		s.recvLock.Unlock()
 		return nil
 	}
 
 	// Update our window
-	atomic.AddUint32(&s.recvWindow, delta)
+	s.recvWindow += delta
+	s.recvLock.Unlock()
 
 	// Send the header
 	s.controlHdr.encode(typeWindowUpdate, flags, s.id, delta)
@@ -396,16 +403,18 @@ func (s *Stream) readData(hdr header, flags uint16, conn io.Reader) error {
 	if length == 0 {
 		return nil
 	}
-	if remain := atomic.LoadUint32(&s.recvWindow); length > remain {
-		s.session.logger.Printf("[ERR] yamux: receive window exceeded (stream: %d, remain: %d, recv: %d)", s.id, remain, length)
-		return ErrRecvWindowExceeded
-	}
 
 	// Wrap in a limited reader
 	conn = &io.LimitedReader{R: conn, N: int64(length)}
 
 	// Copy into buffer
 	s.recvLock.Lock()
+
+	if length > s.recvWindow {
+		s.session.logger.Printf("[ERR] yamux: receive window exceeded (stream: %d, remain: %d, recv: %d)", s.id, s.recvWindow, length)
+		return ErrRecvWindowExceeded
+	}
+
 	if s.recvBuf == nil {
 		// Allocate the receive buffer just-in-time to fit the full data frame.
 		// This way we can read in the whole packet without further allocations.
@@ -418,7 +427,7 @@ func (s *Stream) readData(hdr header, flags uint16, conn io.Reader) error {
 	}
 
 	// Decrement the receive window
-	atomic.AddUint32(&s.recvWindow, ^uint32(length-1))
+	s.recvWindow -= length
 	s.recvLock.Unlock()
 
 	// Unblock any readers

vendor/github.com/hashicorp/yamux/util.go

@@ -1,5 +1,20 @@
 package yamux
 
+import (
+	"sync"
+	"time"
+)
+
+var (
+	timerPool = &sync.Pool{
+		New: func() interface{} {
+			timer := time.NewTimer(time.Hour * 1e6)
+			timer.Stop()
+			return timer
+		},
+	}
+)
+
 // asyncSendErr is used to try an async send of an error
 func asyncSendErr(ch chan error, err error) {
 	if ch == nil {