add comments and better solution for backward compativle

Signed-off-by: Future-Outlier <[email protected]>

flytepropeller/pkg/controller/nodes/task/handler.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"runtime/debug"
+	"strings"
 	"time"
 
 	regErrors "github.com/pkg/errors"
@@ -40,6 +41,7 @@ import (
 )
 
 const pluginContextKey = contextutils.Key("plugin")
+const FLYTE_ENABLE_DECK = string("FLYTE_ENABLE_DECK")
 
 type metrics struct {
 	pluginPanics           labeled.Counter
@@ -83,8 +85,7 @@ func (p *pluginRequestedTransition) AddDeckURI(tCtx *taskExecutionContext) {
 	p.execInfo.OutputInfo.DeckURI = deckURI
 }
 
-// RemoveNonexistentDeckURI removes the deck URI from the plugin execution info if the URI does not exist in remote storage.
-func (p *pluginRequestedTransition) RemoveNonexistentDeckURI(ctx context.Context, tCtx *taskExecutionContext) error {
+func (p *pluginRequestedTransition) AddDeckURIIfDeckExists(ctx context.Context, tCtx *taskExecutionContext) error {
 	reader := tCtx.ow.GetReader()
 	if reader == nil && p.execInfo.OutputInfo != nil {
 		p.execInfo.OutputInfo.DeckURI = nil
@@ -97,8 +98,13 @@ func (p *pluginRequestedTransition) RemoveNonexistentDeckURI(ctx context.Context
 		return regErrors.Wrapf(err, "failed to check existence of deck file")
 	}
 
-	if !exists && p.execInfo.OutputInfo != nil {
-		p.execInfo.OutputInfo.DeckURI = nil
+	if p.execInfo.OutputInfo == nil {
+		p.execInfo.OutputInfo = &handler.OutputInfo{}
+	}
+
+	if exists {
+		deckURIValue := tCtx.ow.GetDeckPath()
+		p.execInfo.OutputInfo.DeckURI = &deckURIValue
 	}
 
 	return nil
@@ -417,6 +423,21 @@ func (t Handler) fetchPluginTaskMetrics(pluginID, taskType string) (*taskMetrics
 	return t.taskMetricsMap[metricNameKey], nil
 }
 
+func IsDeckEnabled(ctx context.Context, tCtx *taskExecutionContext) (bool, error) {
+	template, err := tCtx.tr.Read(ctx)
+	if err != nil {
+		return false, regErrors.Wrapf(err, "failed to read task template")
+	}
+
+	templateConfig := template.GetConfig()
+	if templateConfig == nil {
+		return false, nil
+	}
+
+	deckEnabled := strings.ToLower(templateConfig[FLYTE_ENABLE_DECK])
+	return deckEnabled == "1" || deckEnabled == "t" || deckEnabled == "true", nil
+}
+
 func (t Handler) invokePlugin(ctx context.Context, p pluginCore.Plugin, tCtx *taskExecutionContext, ts handler.TaskNodeState) (*pluginRequestedTransition, error) {
 	pluginTrns := &pluginRequestedTransition{}
 
@@ -505,12 +526,34 @@ func (t Handler) invokePlugin(ctx context.Context, p pluginCore.Plugin, tCtx *ta
 	// The deck should be accessible even if the task is still running or has failed.
 	// It's possible that the deck URI may not exist in remote storage yet or will never exist.
 	// So, it is console's responsibility to handle the case when the deck URI actually does not exist.
-	pluginTrns.AddDeckURI(tCtx)
+	deckEnabled, err := IsDeckEnabled(ctx, tCtx)
+	if err != nil {
+		return nil, err
+	}
+	if deckEnabled {
+		pluginTrns.AddDeckURI(tCtx)
+	}
 
+	// Handle backward compatibility for Flyte deck display behavior.
+	//
+	// Before (legacy behavior):
+	//   - Deck URI was only shown if the deck file existed in the terminal state.
+	//   - We relied on a HEAD request to check if the deck file exists, then added the URI to the event.
+	//
+	// After (new behavior):
+	//   - If `FLYTE_ENABLE_DECK = true` is set in the task template config (requires Flytekit > 1.14.0),
+	//     we display the deck URI from the beginning rather than waiting until the terminal state.
+	//
+	// For backward compatibility with older Flytekit versions (which don't support `FLYTE_ENABLE_DECK`),
+	// we still need to check deck file existence in the terminal state. This ensures that when the deck
+	// isn't enabled via config or doesn't exist, we only show the URI in terminal states if the deck file
+	// is actually present.
 	switch pluginTrns.pInfo.Phase() {
 	case pluginCore.PhaseSuccess:
 		// This is to prevent the console from potentially checking the deck URI that does not exist if in final phase(PhaseSuccess).
-		err = pluginTrns.RemoveNonexistentDeckURI(ctx, tCtx)
+		if !deckEnabled {
+			err = pluginTrns.AddDeckURIIfDeckExists(ctx, tCtx)
+		}
 		if err != nil {
 			return pluginTrns, err
 		}
@@ -559,7 +602,9 @@ func (t Handler) invokePlugin(ctx context.Context, p pluginCore.Plugin, tCtx *ta
 	case pluginCore.PhasePermanentFailure:
 		// This is to prevent the console from potentially checking the deck URI that does not exist if in final
 		// phase(PhaseFailure).
-		err = pluginTrns.RemoveNonexistentDeckURI(ctx, tCtx)
+		if !deckEnabled {
+			err = pluginTrns.AddDeckURIIfDeckExists(ctx, tCtx)
+		}
 		if err != nil {
 			return pluginTrns, err
 		}