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/uber/jaeger-client-go/thrift/memory_buffer.go

@@ -0,0 +1,79 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package thrift
+
+import (
+	"bytes"
+)
+
+// Memory buffer-based implementation of the TTransport interface.
+type TMemoryBuffer struct {
+	*bytes.Buffer
+	size int
+}
+
+type TMemoryBufferTransportFactory struct {
+	size int
+}
+
+func (p *TMemoryBufferTransportFactory) GetTransport(trans TTransport) TTransport {
+	if trans != nil {
+		t, ok := trans.(*TMemoryBuffer)
+		if ok && t.size > 0 {
+			return NewTMemoryBufferLen(t.size)
+		}
+	}
+	return NewTMemoryBufferLen(p.size)
+}
+
+func NewTMemoryBufferTransportFactory(size int) *TMemoryBufferTransportFactory {
+	return &TMemoryBufferTransportFactory{size: size}
+}
+
+func NewTMemoryBuffer() *TMemoryBuffer {
+	return &TMemoryBuffer{Buffer: &bytes.Buffer{}, size: 0}
+}
+
+func NewTMemoryBufferLen(size int) *TMemoryBuffer {
+	buf := make([]byte, 0, size)
+	return &TMemoryBuffer{Buffer: bytes.NewBuffer(buf), size: size}
+}
+
+func (p *TMemoryBuffer) IsOpen() bool {
+	return true
+}
+
+func (p *TMemoryBuffer) Open() error {
+	return nil
+}
+
+func (p *TMemoryBuffer) Close() error {
+	p.Buffer.Reset()
+	return nil
+}
+
+// Flushing a memory buffer is a no-op
+func (p *TMemoryBuffer) Flush() error {
+	return nil
+}
+
+func (p *TMemoryBuffer) RemainingBytes() (num_bytes uint64) {
+	return uint64(p.Buffer.Len())
+}