prepare 6.6.4 release (#168)

docs/configuration.md

@@ -48,7 +48,7 @@ Property in file         | Environment var      | Type    | Default | Descriptio
 `streamUri`              | `STREAM_URI`         | URI     | _(1)_   | URI for the LaunchDarkly streaming service.
 `baseUri`                | `BASE_URI`           | URI     | _(1)_   | URI for the LaunchDarkly polling service for server-side SDKs.
 `clientSideBaseUri`      | `CLIENT_SIDE_BASE_URI` | URI   | _(1)_   | URI for the LaunchDarkly polling service for client-side SDKs.
-`exitOnError`            | `EXIT_ON_ERROR`      | Boolean | `false` | Close the Relay Proxy if it encounters any error during initialization.
+`exitOnError`            | `EXIT_ON_ERROR`      | Boolean | `false` | Close the Relay Proxy if it encounters any error during initialization. The default behavior is that it will terminate (with a non-zero exit code) if the configuration options are completely invalid, or if there is an incorrect `AutoConfig` key, but will remain running if there is an error specific to one environment (such as an invalid SDK key). Setting this option to `true` makes it terminate in both cases.
 `exitAlways`             | `EXIT_ALWAYS`        | Boolean | `false`  | Close the Relay Proxy immediately after initializing all environments (do not start an HTTP server). _(2)_
 `ignoreConnectionErrors` | `IGNORE_CONNECTION_ERRORS` | Boolean | `false` | Ignore any initial connectivity issues with LaunchDarkly. Best used when network connectivity is not reliable.
 `port`                   | `PORT`               | Number  | `8030`  | Port the Relay Proxy should listen on.

internal/autoconfig/stream_manager.go

@@ -2,6 +2,7 @@ package autoconfig
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"regexp"
@@ -86,9 +87,9 @@ func NewStreamManager(
 }
 
 // Start causes the StreamManager to start trying to connect to the auto-config stream. The returned channel
-// receives a value when the connection has either been made or permanently failed.
-func (s *StreamManager) Start() <-chan struct{} {
-	readyCh := make(chan struct{}, 1)
+// receives nil for a successful connection, or an error if it has permanently failed.
+func (s *StreamManager) Start() <-chan error {
+	readyCh := make(chan error, 1)
 	go s.subscribe(readyCh)
 	return readyCh
 }
@@ -100,19 +101,19 @@ func (s *StreamManager) Close() {
 	})
 }
 
-func (s *StreamManager) subscribe(readyCh chan<- struct{}) {
+func (s *StreamManager) subscribe(readyCh chan<- error) {
 	req, _ := http.NewRequest("GET", s.uri, nil)
 	req.Header.Set("Authorization", string(s.key))
 	s.loggers.Infof(logMsgStreamConnecting, s.uri)
 
 	var readyOnce sync.Once
-	signalReady := func() { readyOnce.Do(func() { readyCh <- struct{}{} }) }
+	signalReady := func(err error) { readyOnce.Do(func() { readyCh <- err }) }
 
 	errorHandler := func(err error) es.StreamErrorHandlerResult {
 		if se, ok := err.(es.SubscriptionError); ok {
 			if se.Code == 401 || se.Code == 403 {
 				s.loggers.Error(logMsgBadKey)
-				signalReady()
+				signalReady(errors.New("invalid auto-configuration key"))
 				return es.StreamErrorHandlerResult{CloseNow: true}
 			}
 			s.loggers.Warnf(logMsgStreamHTTPError, se.Code)
@@ -147,11 +148,11 @@ func (s *StreamManager) subscribe(readyCh chan<- struct{}) {
 
 	if err != nil {
 		s.loggers.Errorf(logMsgStreamOtherError, err)
-		signalReady()
+		signalReady(err)
 		return
 	}
 
-	signalReady()
+	signalReady(nil)
 	s.consumeStream(stream)
 }
 

relay/relay.go

@@ -3,6 +3,7 @@ package relay
 import (
 	"errors"
 	"net/http"
+	"os"
 	"time"
 
 	"github.com/launchdarkly/ld-relay/v6/config"
@@ -122,7 +123,18 @@ func newRelayInternal(c config.Config, options relayInternalOptions) (*Relay, er
 			0,
 			core.Loggers,
 		)
-		_ = r.autoConfigStream.Start()
+		autoConfigResult := r.autoConfigStream.Start()
+		go func() {
+			err := <-autoConfigResult
+			if err != nil {
+				// This channel only emits a non-nil error if it's an unrecoverable error, in which case
+				// Relay should quit. The ExitOnError option doesn't affect this, because a failure of
+				// auto-config is more serious than any environment-specific failure; Relay can't possibly
+				// do anything useful without a configuration. The StreamManager has already logged the
+				// error by this point, so we just need to quit.
+				os.Exit(1)
+			}
+		}()
 	}
 
 	if hasFileDataSource {