feat: remove emojis from runner logging, add Starting job container group (#940)

Aligns runner log output more closely with `actions/runner`:

- Strip the whale, rocket, cloud, construction, chequered-flag, and exclamation-mark glyphs from log lines and drop the now-unused `logPrefix` constant.
- Reword `no outputs used step '%s'` → `No outputs registered for step '%s'` (the original was ungrammatical and inaccurate — it fires when `set-output` references an unknown step ID).
- Wrap the docker pull/network/create/start phase of job container startup in a `::group::Starting job container` / `::endgroup::` collapsible section, mirroring `actions/runner`. Since act drives Docker through the SDK rather than the CLI, we can't echo `##[command]/usr/bin/docker create ...` lines verbatim — instead the helper emits a summary inside the group:

  ```
  ::group::Starting job container
  image: <image>
  name: <container-name>
  network: <network-name>
  ::endgroup::
  ```

- Extracted the emit into a `printStartJobContainerGroup` helper (parallel to `printRunActionHeader` in `step_run.go`) and added a golden-style test `TestPrintStartJobContainerGroupGolden`.
- Drive-by: replace two remaining literal `"raw_output"` strings in `run_context.go` with the existing `rawOutputField` constant.

Closes #935

---
This PR was written with the help of Claude Opus 4.7

Reviewed-on: https://gitea.com/gitea/runner/pulls/940
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-committed-by: silverwind <me@silverwind.io>

act/runner/command.go

@@ -120,7 +120,7 @@ func (rc *RunContext) setOutput(ctx context.Context, kvPairs map[string]string,
 
 	result, ok := rc.StepResults[stepID]
 	if !ok {
-		logger.Infof("  \U00002757  no outputs used step '%s'", stepID)
+		logger.Infof("No outputs registered for step '%s'", stepID)
 		return
 	}
 

act/runner/reusable_workflow.go

@@ -278,7 +278,7 @@ func setReusedWorkflowCallerResult(rc *RunContext, runner Runner) common.Executo
 				rc.caller.setReusedWorkflowJobResult(rc.JobName, reusedWorkflowJobResult)
 			} else {
 				rc.result(reusedWorkflowJobResult)
-				logger.WithField("jobResult", reusedWorkflowJobResult).Infof("\U0001F3C1  Job %s", reusedWorkflowJobResultMessage)
+				logger.WithField("jobResult", reusedWorkflowJobResult).Infof("Job %s", reusedWorkflowJobResultMessage)
 			}
 		}
 

act/runner/run_context.go

@@ -193,7 +193,7 @@ func (rc *RunContext) GetBindsAndMounts() ([]string, map[string]string) {
 func (rc *RunContext) startHostEnvironment() common.Executor {
 	return func(ctx context.Context) error {
 		logger := common.Logger(ctx)
-		rawLogger := logger.WithField("raw_output", true)
+		rawLogger := logger.WithField(rawOutputField, true)
 		logWriter := common.NewLineWriter(rc.commandHandler(ctx), func(s string) bool {
 			if rc.Config.LogOutput {
 				rawLogger.Infof("%s", s)
@@ -260,11 +260,24 @@ func (rc *RunContext) startHostEnvironment() common.Executor {
 	}
 }
 
+// printStartJobContainerGroup mirrors actions/runner's "Starting job container"
+// section: emit the group header and summary, return a closer for ::endgroup::.
+func printStartJobContainerGroup(ctx context.Context, image, name, network string) func() {
+	rawLogger := common.Logger(ctx).WithField(rawOutputField, true)
+	rawLogger.Infof("::group::Starting job container")
+	rawLogger.Infof("image: %s", image)
+	rawLogger.Infof("name: %s", name)
+	rawLogger.Infof("network: %s", network)
+	return func() {
+		rawLogger.Infof("::endgroup::")
+	}
+}
+
 func (rc *RunContext) startJobContainer() common.Executor {
 	return func(ctx context.Context) error {
 		logger := common.Logger(ctx)
 		image := rc.platformImage(ctx)
-		rawLogger := logger.WithField("raw_output", true)
+		rawLogger := logger.WithField(rawOutputField, true)
 		logWriter := common.NewLineWriter(rc.commandHandler(ctx), func(s string) bool {
 			if rc.Config.LogOutput {
 				rawLogger.Infof("%s", s)
@@ -279,7 +292,6 @@ func (rc *RunContext) startJobContainer() common.Executor {
 			return fmt.Errorf("failed to handle credentials: %s", err)
 		}
 
-		logger.Infof("\U0001f680  Start image=%s", image)
 		name := rc.jobContainerName()
 		// For gitea, to support --volumes-from <container_name_or_id> in options.
 		// We need to set the container name to the environment variable.
@@ -424,6 +436,7 @@ func (rc *RunContext) startJobContainer() common.Executor {
 			return errors.New("Failed to create job container")
 		}
 
+		defer printStartJobContainerGroup(ctx, image, name, networkName)()
 		return common.NewPipelineExecutor(
 			rc.pullServicesImages(rc.Config.ForcePull),
 			rc.JobContainer.Pull(rc.Config.ForcePull),
@@ -753,7 +766,7 @@ func (rc *RunContext) isEnabled(ctx context.Context) (bool, error) {
 	img := rc.platformImage(ctx)
 	if img == "" {
 		for _, platformName := range rc.runsOnPlatformNames(ctx) {
-			l.Infof("\U0001F6A7  Skipping unsupported platform -- Try running with `-P %+v=...`", platformName)
+			l.Infof("Skipping unsupported platform -- Try running with `-P %+v=...`", platformName)
 		}
 		return false, nil
 	}

act/runner/run_context_test.go

@@ -5,6 +5,7 @@
 package runner
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"os"
@@ -12,6 +13,7 @@ import (
 	"strings"
 	"testing"
 
+	"gitea.com/gitea/runner/act/common"
 	"gitea.com/gitea/runner/act/exprparser"
 	"gitea.com/gitea/runner/act/model"
 
@@ -635,3 +637,25 @@ func TestCreateContainerNameBoundedForLongMatrixInput(t *testing.T) {
 	assert.LessOrEqual(t, len(name+"-network"), 255)
 	assert.LessOrEqual(t, len(name+"-job1234567890"), 255)
 }
+
+func TestPrintStartJobContainerGroupGolden(t *testing.T) {
+	buf := &bytes.Buffer{}
+	logger := log.New()
+	logger.SetOutput(buf)
+	logger.SetLevel(log.InfoLevel)
+	logger.SetFormatter(&jobLogFormatter{color: cyan})
+	entry := logger.WithFields(log.Fields{"job": "j1"})
+	ctx := common.WithLogger(context.Background(), entry)
+
+	printStartJobContainerGroup(ctx, "node:20", "GITEA-WORKFLOW-build-JOB-test", "gitea-runner-network")()
+
+	want := strings.Join([]string{
+		"[j1]   | ::group::Starting job container",
+		"[j1]   | image: node:20",
+		"[j1]   | name: GITEA-WORKFLOW-build-JOB-test",
+		"[j1]   | network: gitea-runner-network",
+		"[j1]   | ::endgroup::",
+		"",
+	}, "\n")
+	assert.Equal(t, want, buf.String())
+}