fix: Allow log streaming to take longer than build execution

cmd/vela-worker/exec.go

@@ -6,6 +6,7 @@ package main
 
 import (
 	"context"
+	"sync"
 	"time"
 
 	"github.com/go-vela/worker/executor"
@@ -75,6 +76,7 @@ func (w *Worker) exec(index int) error {
 		Driver:              w.Config.Executor.Driver,
 		LogMethod:           w.Config.Executor.LogMethod,
 		MaxLogSize:          w.Config.Executor.MaxLogSize,
+		LogStreamingTimeout: w.Config.Executor.LogStreamingTimeout,
 		EnforceTrustedRepos: w.Config.Executor.EnforceTrustedRepos,
 		PrivilegedImages:    w.Config.Runtime.PrivilegedImages,
 		Client:              w.VelaClient,
@@ -108,7 +110,13 @@ func (w *Worker) exec(index int) error {
 	timeoutCtx, timeout := context.WithTimeout(buildCtx, t)
 	defer timeout()
 
+	// This WaitGroup delays calling DestroyBuild until the StreamBuild goroutine finishes.
+	var wg sync.WaitGroup
+
 	defer func() {
+		// if exec() exits before starting StreamBuild, this returns immediately.
+		wg.Wait()
+
 		logger.Info("destroying build")
 
 		// destroy the build with the executor (pass a background
@@ -137,8 +145,12 @@ func (w *Worker) exec(index int) error {
 		return nil
 	}
 
+	// add StreamBuild goroutine to WaitGroup
+	wg.Add(1)
+
 	// log/event streaming uses buildCtx so that it is not subject to the timeout.
 	go func() {
+		defer wg.Done()
 		logger.Info("streaming build logs")
 		// execute the build with the executor
 		err = _executor.StreamBuild(buildCtx)

cmd/vela-worker/run.go

@@ -96,6 +96,7 @@ func run(c *cli.Context) error {
 				Driver:              c.String("executor.driver"),
 				LogMethod:           c.String("executor.log_method"),
 				MaxLogSize:          c.Uint("executor.max_log_size"),
+				LogStreamingTimeout: c.Duration("executor.log_streaming_timeout"),
 				EnforceTrustedRepos: c.Bool("executor.enforce-trusted-repos"),
 			},
 			// logger configuration

executor/flags.go

@@ -5,6 +5,8 @@
 package executor
 
 import (
+	"time"
+
 	"github.com/go-vela/types/constants"
 
 	"github.com/urfave/cli/v2"
@@ -37,6 +39,12 @@ var Flags = []cli.Flag{
 		Name:     "executor.max_log_size",
 		Usage:    "maximum log size (in bytes)",
 	},
+	&cli.DurationFlag{
+		EnvVars: []string{"WORKER_LOG_STREAMING_TIMEOUT", "VELA_LOG_STREAMING_TIMEOUT", "LOG_STREAMING_TIMEOUT"},
+		Name:    "executor.log_streaming_timeout",
+		Usage:   "maximum amount of time to wait for log streaming after build completes",
+		Value:   5 * time.Minute,
+	},
 	&cli.BoolFlag{
 		EnvVars:  []string{"VELA_EXECUTOR_ENFORCE_TRUSTED_REPOS", "EXECUTOR_ENFORCE_TRUSTED_REPOS"},
 		FilePath: "/vela/executor/enforce_trusted_repos",

executor/linux/build.go

@@ -16,6 +16,7 @@ import (
 	"github.com/go-vela/types/constants"
 	"github.com/go-vela/types/library"
 	"github.com/go-vela/worker/internal/build"
+	context2 "github.com/go-vela/worker/internal/context"
 	"github.com/go-vela/worker/internal/image"
 	"github.com/go-vela/worker/internal/step"
 )
@@ -566,10 +567,15 @@ func (c *client) ExecBuild(ctx context.Context) error {
 // StreamBuild receives a StreamRequest and then
 // runs StreamService or StreamStep in a goroutine.
 func (c *client) StreamBuild(ctx context.Context) error {
+	// cancel streaming after a timeout once the build has finished
+	delayedCtx, cancelStreaming := context2.
+		WithDelayedCancelPropagation(ctx, c.logStreamingTimeout, "streaming", c.Logger)
+	defer cancelStreaming()
+
 	// create an error group with the parent context
 	//
 	// https://pkg.go.dev/golang.org/x/sync/errgroup?tab=doc#WithContext
-	streams, streamCtx := errgroup.WithContext(ctx)
+	streams, streamCtx := errgroup.WithContext(delayedCtx)
 
 	defer func() {
 		c.Logger.Trace("waiting for stream functions to return")
@@ -579,6 +585,8 @@ func (c *client) StreamBuild(ctx context.Context) error {
 			c.Logger.Errorf("error in a stream request, %v", err)
 		}
 
+		cancelStreaming()
+
 		c.Logger.Info("all stream functions have returned")
 	}()
 
@@ -607,7 +615,7 @@ func (c *client) StreamBuild(ctx context.Context) error {
 
 				return nil
 			})
-		case <-ctx.Done():
+		case <-delayedCtx.Done():
 			c.Logger.Debug("streaming context canceled")
 			// build done or canceled
 			return nil

executor/linux/build_test.go

@@ -1238,6 +1238,7 @@ func TestLinux_StreamBuild(t *testing.T) {
 				WithPipeline(_pipeline),
 				WithRepo(_repo),
 				WithRuntime(_runtime),
+				WithLogStreamingTimeout(1*time.Second),
 				WithUser(_user),
 				WithVelaClient(_client),
 				withStreamRequests(streamRequests),

executor/linux/linux.go

@@ -7,6 +7,7 @@ package linux
 import (
 	"reflect"
 	"sync"
+	"time"
 
 	"github.com/go-vela/sdk-go/vela"
 	"github.com/go-vela/types/library"
@@ -34,6 +35,7 @@ type (
 		init                *pipeline.Container
 		logMethod           string
 		maxLogSize          uint
+		logStreamingTimeout time.Duration
 		privilegedImages    []string
 		enforceTrustedRepos bool
 		build               *library.Build

executor/linux/opts.go

@@ -6,6 +6,7 @@ package linux
 
 import (
 	"fmt"
+	"time"
 
 	"github.com/go-vela/sdk-go/vela"
 	"github.com/go-vela/types/library"
@@ -64,6 +65,18 @@ func WithMaxLogSize(size uint) Opt {
 	}
 }
 
+// WithLogStreamingTimeout sets the log streaming timeout in the executor client for Linux.
+func WithLogStreamingTimeout(timeout time.Duration) Opt {
+	return func(c *client) error {
+		c.Logger.Trace("configuring log streaming timeout in linux executor client")
+
+		// set the maximum log size in the client
+		c.logStreamingTimeout = timeout
+
+		return nil
+	}
+}
+
 // WithPrivilegedImages sets the privileged images in the executor client for Linux.
 func WithPrivilegedImages(images []string) Opt {
 	return func(c *client) error {

executor/linux/opts_test.go

@@ -8,6 +8,7 @@ import (
 	"net/http/httptest"
 	"reflect"
 	"testing"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	"github.com/sirupsen/logrus"
@@ -161,6 +162,46 @@ func TestLinux_Opt_WithMaxLogSize(t *testing.T) {
 	}
 }
 
+func TestLinux_Opt_WithLogStreamingTimeout(t *testing.T) {
+	// setup tests
+	tests := []struct {
+		name                string
+		failure             bool
+		logStreamingTimeout time.Duration
+	}{
+		{
+			name:                "defined",
+			failure:             false,
+			logStreamingTimeout: 1 * time.Second,
+		},
+	}
+
+	// run tests
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			_engine, err := New(
+				WithLogStreamingTimeout(test.logStreamingTimeout),
+			)
+
+			if test.failure {
+				if err == nil {
+					t.Errorf("WithLogStreamingTimeout should have returned err")
+				}
+
+				return // continue to next test
+			}
+
+			if err != nil {
+				t.Errorf("WithLogStreamingTimeout returned err: %v", err)
+			}
+
+			if !reflect.DeepEqual(_engine.logStreamingTimeout, test.logStreamingTimeout) {
+				t.Errorf("WithLogStreamingTimeout is %v, want %v", _engine.logStreamingTimeout, test.logStreamingTimeout)
+			}
+		})
+	}
+}
+
 func TestLinux_Opt_WithPrivilegedImages(t *testing.T) {
 	// setup tests
 	tests := []struct {

executor/setup.go

@@ -7,6 +7,7 @@ package executor
 import (
 	"fmt"
 	"strings"
+	"time"
 
 	"github.com/go-vela/sdk-go/vela"
 
@@ -40,6 +41,9 @@ type Setup struct {
 	LogMethod string
 	// specifies the maximum log size
 	MaxLogSize uint
+	// specifies how long to wait after the build finishes
+	// for log streaming to complete
+	LogStreamingTimeout time.Duration
 	// specifies a list of privileged images to use
 	PrivilegedImages []string
 	// configuration for enforcing that only trusted repos may run privileged images
@@ -85,6 +89,7 @@ func (s *Setup) Linux() (Engine, error) {
 		linux.WithBuild(s.Build),
 		linux.WithLogMethod(s.LogMethod),
 		linux.WithMaxLogSize(s.MaxLogSize),
+		linux.WithLogStreamingTimeout(s.LogStreamingTimeout),
 		linux.WithPrivilegedImages(s.PrivilegedImages),
 		linux.WithEnforceTrustedRepos(s.EnforceTrustedRepos),
 		linux.WithHostname(s.Hostname),

executor/setup_test.go

@@ -7,6 +7,7 @@ package executor
 import (
 	"net/http/httptest"
 	"testing"
+	"time"
 
 	"github.com/gin-gonic/gin"
 	"github.com/google/go-cmp/cmp"
@@ -79,6 +80,7 @@ func TestExecutor_Setup_Linux(t *testing.T) {
 		linux.WithBuild(_build),
 		linux.WithLogMethod("byte-chunks"),
 		linux.WithMaxLogSize(2097152),
+		linux.WithLogStreamingTimeout(1*time.Second),
 		linux.WithHostname("localhost"),
 		linux.WithPipeline(_pipeline),
 		linux.WithRepo(_repo),

internal/context/context.go

@@ -0,0 +1,49 @@
+// Copyright (c) 2022 Target Brands, Inc. All rights reserved.
+//
+// Use of this source code is governed by the LICENSE file in this repository.
+
+package context
+
+import (
+	"context"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+func WithDelayedCancelPropagation(parent context.Context, timeout time.Duration, name string, logger *logrus.Entry) (context.Context, context.CancelFunc) {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	go func() {
+		var timer *time.Timer
+
+		// start the timer once the parent context is canceled
+		select {
+		case <-parent.Done():
+			logger.Tracef("parent context is done, starting %s timer for %s", name, timeout)
+			timer = time.NewTimer(timeout)
+
+			break
+		case <-ctx.Done():
+			logger.Tracef("%s finished before the parent context", name)
+
+			return
+		}
+
+		// wait for the timer to elapse or the context to naturally finish.
+		select {
+		case <-timer.C:
+			logger.Tracef("%s timed out, propagating cancel to %s context", name, name)
+			cancel()
+
+			return
+		case <-ctx.Done():
+			logger.Tracef("%s finished, stopping timeout timer", name)
+			timer.Stop()
+
+			return
+		}
+	}()
+
+	return ctx, cancel
+}