Change async event delivery to single goroutine with events channel queue

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## TBD
+
+### Enhancements
+
+* Limit resource usage while sending events asynchronously \
+  Added MainContext configuration option for providing context from main app
+  [#231](https://github.com/bugsnag/bugsnag-go/pull/231)
+
 ## 2.4.0 (2024-04-15)
 
 ### Enhancements

LOCAL_TESTING.md

@@ -0,0 +1,29 @@
+
+## Unit tests
+* Install old golang version (do not install just 1.11 - it's not compatible with running newer modules): 
+
+```
+ASDF_GOLANG_OVERWRITE_ARCH=amd64 asdf install golang 1.11.13
+```
+
+* If you see error below use `CGO_ENABLED=0`.
+
+```
+# crypto/x509
+malformed DWARF TagVariable entry
+```
+
+## Local testing with maze runner
+
+* Maze runner tests require
+  * Specyfing `GO_VERSION` env variable to set a golang version for docker container.
+  * Ruby 2.7.
+  * Running docker.
+
+* Commands to run tests
+
+```
+	bundle install
+	bundle exec bugsnag-maze-runner
+  bundle exec bugsnag-maze-runner -c features/<chosen_feature>
+```

features/fixtures/app/Dockerfile

@@ -1,7 +1,7 @@
 ARG GO_VERSION
 FROM golang:${GO_VERSION}-alpine
 
-RUN apk update && apk upgrade && apk add git bash
+RUN apk update && apk upgrade && apk add git bash build-base
 
 ENV GOPATH /app
 
@@ -28,6 +28,8 @@ WORKDIR /app/src/test
 # Skip on old versions of Go which pre-date modules
 RUN if [[ $GO_VERSION != '1.11' && $GO_VERSION != '1.12' ]]; then \
         go mod init && go mod tidy; \
+        echo "replace github.com/bugsnag/bugsnag-go/v2 => /app/src/github.com/bugsnag/bugsnag-go/v2" >> go.mod; \
+        go mod tidy; \
     fi
 
 RUN chmod +x run.sh

features/fixtures/app/main.go

@@ -14,12 +14,13 @@ import (
 	bugsnag "github.com/bugsnag/bugsnag-go/v2"
 )
 
-func configureBasicBugsnag(testcase string) {
+func configureBasicBugsnag(testcase string, ctx context.Context) {
 	config := bugsnag.Configuration{
-		APIKey:     os.Getenv("API_KEY"),
-		AppVersion: os.Getenv("APP_VERSION"),
-		AppType:    os.Getenv("APP_TYPE"),
-		Hostname:   os.Getenv("HOSTNAME"),
+		APIKey:      os.Getenv("API_KEY"),
+		AppVersion:  os.Getenv("APP_VERSION"),
+		AppType:     os.Getenv("APP_TYPE"),
+		Hostname:    os.Getenv("HOSTNAME"),
+		MainContext: ctx,
 	}
 
 	if notifyReleaseStages := os.Getenv("NOTIFY_RELEASE_STAGES"); notifyReleaseStages != "" {
@@ -63,11 +64,13 @@ func configureBasicBugsnag(testcase string) {
 }
 
 func main() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
 
 	test := flag.String("test", "handled", "what the app should send, either handled, unhandled, session, autonotify")
 	flag.Parse()
 
-	configureBasicBugsnag(*test)
+	configureBasicBugsnag(*test, ctx)
 	time.Sleep(100 * time.Millisecond) // Ensure tests are less flaky by ensuring the start-up session gets sent
 
 	switch *test {

features/fixtures/autoconfigure/Dockerfile

@@ -1,7 +1,7 @@
 ARG GO_VERSION
 FROM golang:${GO_VERSION}-alpine
 
-RUN apk update && apk upgrade && apk add git bash
+RUN apk update && apk upgrade && apk add git bash build-base
 
 ENV GOPATH /app
 
@@ -28,6 +28,8 @@ WORKDIR /app/src/test
 # Skip on old versions of Go which pre-date modules
 RUN if [[ $GO_VERSION != '1.11' && $GO_VERSION != '1.12' ]]; then \
         go mod init && go mod tidy; \
+        echo "replace github.com/bugsnag/bugsnag-go/v2 => /app/src/github.com/bugsnag/bugsnag-go/v2" >> go.mod; \
+        go mod tidy; \
     fi
 
 RUN chmod +x run.sh

features/fixtures/net_http/Dockerfile

@@ -3,7 +3,7 @@ FROM golang:${GO_VERSION}-alpine
 
 RUN apk update && \
     apk upgrade && \
-    apk add git
+    apk add git build-base
 
 ENV GOPATH /app
 
@@ -30,4 +30,6 @@ WORKDIR /app/src/test
 # Skip on old versions of Go which pre-date modules
 RUN if [[ $GO_VERSION != '1.11' && $GO_VERSION != '1.12' ]]; then \
         go mod init && go mod tidy; \
+        echo "replace github.com/bugsnag/bugsnag-go/v2 => /app/src/github.com/bugsnag/bugsnag-go/v2" >> go.mod; \
+        go mod tidy; \
     fi

features/fixtures/net_http/main.go

@@ -14,7 +14,9 @@ import (
 )
 
 func main() {
-	configureBasicBugsnag()
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	configureBasicBugsnag(ctx)
 
 	http.HandleFunc("/handled", handledError)
 	http.HandleFunc("/autonotify-then-recover", unhandledCrash)
@@ -40,16 +42,17 @@ func recoverWrap(h http.Handler) http.Handler {
 	})
 }
 
-func configureBasicBugsnag() {
+func configureBasicBugsnag(ctx context.Context) {
 	config := bugsnag.Configuration{
 		APIKey: os.Getenv("API_KEY"),
 		Endpoints: bugsnag.Endpoints{
 			Notify:   os.Getenv("BUGSNAG_ENDPOINT"),
 			Sessions: os.Getenv("BUGSNAG_ENDPOINT"),
 		},
-		AppVersion: os.Getenv("APP_VERSION"),
-		AppType:    os.Getenv("APP_TYPE"),
-		Hostname:   os.Getenv("HOSTNAME"),
+		AppVersion:  os.Getenv("APP_VERSION"),
+		AppType:     os.Getenv("APP_TYPE"),
+		Hostname:    os.Getenv("HOSTNAME"),
+		MainContext: ctx,
 	}
 
 	if notifyReleaseStages := os.Getenv("NOTIFY_RELEASE_STAGES"); notifyReleaseStages != "" {

features/handled.feature

@@ -37,7 +37,7 @@ Scenario: Sending an event using a callback to modify report contents
   And the event "severityReason.type" equals "userCallbackSetSeverity"
   And the event "context" equals "nonfatal.go:14"
   And the "file" of stack frame 0 equals "main.go"
-  And stack frame 0 contains a local function spanning 242 to 248
+  And stack frame 0 contains a local function spanning 245 to 253
   And the "file" of stack frame 1 equals ">insertion<"
   And the "lineNumber" of stack frame 1 equals 0
 
@@ -50,7 +50,7 @@ Scenario: Marking an error as unhandled in a callback
   And the event "severityReason.type" equals "userCallbackSetSeverity"
   And the event "severityReason.unhandledOverridden" is true
   And the "file" of stack frame 0 equals "main.go"
-  And stack frame 0 contains a local function spanning 254 to 257
+  And stack frame 0 contains a local function spanning 257 to 262
 
 Scenario: Unwrapping the causes of a handled error
   When I run the go service "app" with the test case "nested-error"
@@ -59,12 +59,12 @@ Scenario: Unwrapping the causes of a handled error
   And the event "unhandled" is false
   And the event "severity" equals "warning"
   And the event "exceptions.0.message" equals "terminate process"
-  And the "lineNumber" of stack frame 0 equals 292
+  And the "lineNumber" of stack frame 0 equals 295
   And the "file" of stack frame 0 equals "main.go"
   And the "method" of stack frame 0 equals "nestedHandledError"
   And the event "exceptions.1.message" equals "login failed"
   And the event "exceptions.1.stacktrace.0.file" equals "main.go"
-  And the event "exceptions.1.stacktrace.0.lineNumber" equals 312
+  And the event "exceptions.1.stacktrace.0.lineNumber" equals 315
   And the event "exceptions.2.message" equals "invalid token"
   And the event "exceptions.2.stacktrace.0.file" equals "main.go"
-  And the event "exceptions.2.stacktrace.0.lineNumber" equals 320
+  And the event "exceptions.2.stacktrace.0.lineNumber" equals 323

v2/bugsnag_test.go

@@ -16,6 +16,10 @@ import (
 	"github.com/bugsnag/bugsnag-go/v2/sessions"
 )
 
+// ATTENTION - tests in this file are changing global state variables
+// like default config or default report publisher
+// TAKE CARE to reset them to default after testcase!
+
 // The line numbers of this method are used in tests.
 // If you move this function you'll have to change tests
 func crashyHandler(w http.ResponseWriter, r *http.Request) {
@@ -132,7 +136,7 @@ func TestNotify(t *testing.T) {
 	}
 
 	exception := getIndex(event, "exceptions", 0)
-	verifyExistsInStackTrace(t, exception, &StackFrame{File: "bugsnag_test.go", Method: "TestNotify", LineNumber: 98, InProject: true})
+	verifyExistsInStackTrace(t, exception, &StackFrame{File: "bugsnag_test.go", Method: "TestNotify", LineNumber: 102, InProject: true})
 }
 
 type testPublisher struct {
@@ -144,6 +148,9 @@ func (tp *testPublisher) publishReport(p *payload) error {
 	return nil
 }
 
+func (tp *testPublisher) setMainProgramContext(context.Context) {
+}
+
 func TestNotifySyncThenAsync(t *testing.T) {
 	ts, _ := setup()
 	defer ts.Close()
@@ -152,7 +159,7 @@ func TestNotifySyncThenAsync(t *testing.T) {
 
 	pub := new(testPublisher)
 	publisher = pub
-	defer func() { publisher = new(defaultReportPublisher) }()
+	defer func() { publisher = newPublisher() }()
 
 	Notify(fmt.Errorf("oopsie"))
 	if pub.sync {
@@ -175,6 +182,7 @@ func TestHandlerFunc(t *testing.T) {
 	defer eventserver.Close()
 	Configure(generateSampleConfig(eventserver.URL))
 
+	// NOTE - this testcase will print a panic in verbose mode
 	t.Run("unhandled", func(st *testing.T) {
 		sessionTracker = nil
 		startSessionTracking()
@@ -315,7 +323,7 @@ func TestHandler(t *testing.T) {
 	}
 
 	exception := getIndex(event, "exceptions", 0)
-	verifyExistsInStackTrace(t, exception, &StackFrame{File: "bugsnag_test.go", Method: "crashyHandler", InProject: true, LineNumber: 24})
+	verifyExistsInStackTrace(t, exception, &StackFrame{File: "bugsnag_test.go", Method: "crashyHandler", InProject: true, LineNumber: 28})
 }
 
 func TestAutoNotify(t *testing.T) {

v2/configuration.go

@@ -1,6 +1,7 @@
 package bugsnag
 
 import (
+	"context"
 	"log"
 	"net/http"
 	"os"
@@ -101,6 +102,12 @@ type Configuration struct {
 	// Whether bugsnag should notify synchronously. This defaults to false which
 	// causes bugsnag-go to spawn a new goroutine for each notification.
 	Synchronous bool
+
+	// Context created in the main program
+	// Used in event delivery - after this context is marked Done
+	// the event sending goroutine will switch to a graceful shutdown
+	// and will try to send any remaining events.
+	MainContext context.Context
 	// Whether the notifier should send all sessions recorded so far to Bugsnag
 	// when repanicking to ensure that no session information is lost in a
 	// fatal crash.
@@ -160,6 +167,10 @@ func (config *Configuration) update(other *Configuration) *Configuration {
 	if other.Synchronous {
 		config.Synchronous = true
 	}
+	if other.MainContext != nil {
+		config.MainContext = other.MainContext
+		publisher.setMainProgramContext(other.MainContext)
+	}
 
 	if other.AutoCaptureSessions != nil {
 		config.AutoCaptureSessions = other.AutoCaptureSessions

v2/notifier.go

@@ -4,7 +4,7 @@ import (
 	"github.com/bugsnag/bugsnag-go/v2/errors"
 )
 
-var publisher reportPublisher = new(defaultReportPublisher)
+var publisher reportPublisher = newPublisher()
 
 // Notifier sends errors to Bugsnag.
 type Notifier struct {
@@ -84,10 +84,11 @@ func (notifier *Notifier) NotifySync(err error, sync bool, rawData ...interface{
 // AutoNotify notifies Bugsnag of any panics, then repanics.
 // It sends along any rawData that gets passed in.
 // Usage:
-//  go func() {
-//		defer AutoNotify()
-//      // (possibly crashy code)
-//  }()
+//
+//	 go func() {
+//			defer AutoNotify()
+//	     // (possibly crashy code)
+//	 }()
 func (notifier *Notifier) AutoNotify(rawData ...interface{}) {
 	if err := recover(); err != nil {
 		severity := notifier.getDefaultSeverity(rawData, SeverityError)