roachtest/roachtestutil: move LoggerForCmd to roachtestutil

This helper was previously used exclusively for roachtest
run calls, where a quiet logger would be created for remote
commands so as to not create noise in the test log.

This change extracts that helper to roachtestutil as creating
quiet loggers can be useful outside of remote run calls.

Author: DarrylWong

pkg/cmd/roachtest/cluster.go

@@ -2501,7 +2501,7 @@ func (c *clusterImpl) RunE(ctx context.Context, options install.RunOptions, args
 		return errors.New("No command passed")
 	}
 	nodes := option.FromInstallNodes(options.Nodes)
-	l, logFile, err := c.loggerForCmd(nodes, args...)
+	l, logFile, err := roachtestutil.LoggerForCmd(c.l, nodes, args...)
 	if err != nil {
 		return err
 	}
@@ -2569,7 +2569,7 @@ func (c *clusterImpl) RunWithDetails(
 		return nil, errors.New("No command passed")
 	}
 	nodes := option.FromInstallNodes(options.Nodes)
-	l, logFile, err := c.loggerForCmd(nodes, args...)
+	l, logFile, err := roachtestutil.LoggerForCmd(c.l, nodes, args...)
 	if err != nil {
 		return nil, err
 	}
@@ -2653,30 +2653,6 @@ func (c *clusterImpl) Install(
 	return errors.Wrap(roachprod.Install(ctx, l, c.MakeNodes(nodes), software), "cluster.Install")
 }
 
-// cmdLogFileName comes up with a log file to use for the given argument string.
-func cmdLogFileName(t time.Time, nodes option.NodeListOption, args ...string) string {
-	logFile := fmt.Sprintf(
-		"run_%s_n%s_%s",
-		t.Format(`150405.000000000`),
-		nodes.String()[1:],
-		install.GenFilenameFromArgs(20, args...),
-	)
-	return logFile
-}
-
-func (c *clusterImpl) loggerForCmd(
-	node option.NodeListOption, args ...string,
-) (*logger.Logger, string, error) {
-	logFile := cmdLogFileName(timeutil.Now(), node, args...)
-
-	// NB: we set no prefix because it's only going to a file anyway.
-	l, err := c.l.ChildLogger(logFile, logger.QuietStderr, logger.QuietStdout)
-	if err != nil {
-		return nil, "", err
-	}
-	return l, logFile, nil
-}
-
 // pgURLErr returns the Postgres endpoint for the specified nodes. It accepts a
 // flag specifying whether the URL should include the node's internal or
 // external IP address. In general, inter-cluster communication and should use

pkg/cmd/roachtest/cluster_test.go

@@ -11,7 +11,6 @@ import (
 	"strconv"
 	"strings"
 	"testing"
-	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/cmd/roachtest/option"
 	"github.com/cockroachdb/cockroach/pkg/cmd/roachtest/roachtestutil/task"
@@ -24,7 +23,6 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/util/version"
 	"github.com/cockroachdb/datadriven"
 	"github.com/cockroachdb/errors"
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -686,21 +684,6 @@ func TestMachineTypes(t *testing.T) {
 	})
 }
 
-func TestCmdLogFileName(t *testing.T) {
-	ts := time.Date(2000, 1, 1, 15, 4, 12, 0, time.Local)
-
-	const exp = `run_150412.000000000_n1,3-4,9_cockroach-bla-foo-ba`
-	nodes := option.NodeListOption{1, 3, 4, 9}
-	assert.Equal(t,
-		exp,
-		cmdLogFileName(ts, nodes, "./cockroach", "bla", "--foo", "bar"),
-	)
-	assert.Equal(t,
-		exp,
-		cmdLogFileName(ts, nodes, "./cockroach bla --foo bar"),
-	)
-}
-
 func TestVerifyLibraries(t *testing.T) {
 	originalLibraryPaths := libraryFilePaths
 	defer func() { libraryFilePaths = originalLibraryPaths }()

pkg/cmd/roachtest/roachtestutil/BUILD.bazel

@@ -51,10 +51,12 @@ go_test(
     srcs = [
         "commandbuilder_test.go",
         "load_group_test.go",
+        "utils_test.go",
     ],
     embed = [":roachtestutil"],
     deps = [
         "//pkg/cmd/roachtest/option",
+        "@com_github_stretchr_testify//assert",
         "@com_github_stretchr_testify//require",
     ],
 )

pkg/cmd/roachtest/roachtestutil/utils.go

@@ -219,6 +219,31 @@ func IfLocal(c cluster.Cluster, trueVal, falseVal string) string {
 	return falseVal
 }
 
+// LoggerForCmd creates a logger to a file with quiet stdout and stderr.
+func LoggerForCmd(
+	l *logger.Logger, node option.NodeListOption, args ...string,
+) (*logger.Logger, string, error) {
+	logFile := cmdLogFileName(timeutil.Now(), node, args...)
+
+	// NB: we set no prefix because it's only going to a file anyway.
+	l, err := l.ChildLogger(logFile, logger.QuietStderr, logger.QuietStdout)
+	if err != nil {
+		return nil, "", err
+	}
+	return l, logFile, nil
+}
+
+// cmdLogFileName comes up with a log file to use for the given argument string.
+func cmdLogFileName(t time.Time, nodes option.NodeListOption, args ...string) string {
+	logFile := fmt.Sprintf(
+		"run_%s_n%s_%s",
+		t.Format(`150405.000000000`),
+		nodes.String()[1:],
+		install.GenFilenameFromArgs(20, args...),
+	)
+	return logFile
+}
+
 // CheckPortBlocked returns true if a connection from a node to a port on another node
 // can be established. Requires nmap to be installed.
 func CheckPortBlocked(

pkg/cmd/roachtest/roachtestutil/utils_test.go

@@ -0,0 +1,29 @@
+// Copyright 2025 The Cockroach Authors.
+//
+// Use of this software is governed by the CockroachDB Software License
+// included in the /LICENSE file.
+
+package roachtestutil
+
+import (
+	"testing"
+	"time"
+
+	"github.com/cockroachdb/cockroach/pkg/cmd/roachtest/option"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCmdLogFileName(t *testing.T) {
+	ts := time.Date(2000, 1, 1, 15, 4, 12, 0, time.Local)
+
+	const exp = `run_150412.000000000_n1,3-4,9_cockroach-bla-foo-ba`
+	nodes := option.NodeListOption{1, 3, 4, 9}
+	assert.Equal(t,
+		exp,
+		cmdLogFileName(ts, nodes, "./cockroach", "bla", "--foo", "bar"),
+	)
+	assert.Equal(t,
+		exp,
+		cmdLogFileName(ts, nodes, "./cockroach bla --foo bar"),
+	)
+}

pkg/cmd/roachtest/tests/failure_injection.go

@@ -46,32 +46,68 @@ func (t *failureSmokeTest) run(
 	}
 	// Make sure to cleanup the failure mode even if the test fails.
 	defer func() {
-		err = errors.CombineErrors(err, failureMode.Cleanup(ctx, l, t.args))
+		quietLogger, file, logErr := roachtestutil.LoggerForCmd(l, c.CRDBNodes(), t.testName, "cleanup")
+		if logErr != nil {
+			l.Printf("failed to create logger for cleanup: %v", logErr)
+			quietLogger = l
+		}
+		l.Printf("%s: Running Cleanup(); details in %s.log", t.failureName, file)
+		err = errors.CombineErrors(err, failureMode.Cleanup(ctx, quietLogger, t.args))
 	}()
-	if err = failureMode.Setup(ctx, l, t.args); err != nil {
+
+	quietLogger, file, err := roachtestutil.LoggerForCmd(l, c.CRDBNodes(), t.testName, "setup")
+	if err != nil {
+		return err
+	}
+	l.Printf("%s: Running Setup(); details in %s.log", t.failureName, file)
+	if err = failureMode.Setup(ctx, quietLogger, t.args); err != nil {
 		return err
 	}
-	if err = failureMode.Inject(ctx, l, t.args); err != nil {
+
+	quietLogger, file, err = roachtestutil.LoggerForCmd(l, c.CRDBNodes(), t.testName, "inject")
+	if err != nil {
+		return err
+	}
+	l.Printf("%s: Running Inject(); details in %s.log", t.failureName, file)
+	if err = failureMode.Inject(ctx, quietLogger, t.args); err != nil {
 		return err
 	}
 
 	// Allow the failure to take effect.
-	if err = failureMode.WaitForFailureToPropagate(ctx, l, t.args); err != nil {
+	quietLogger, file, err = roachtestutil.LoggerForCmd(l, c.CRDBNodes(), t.testName, "wait for propagate")
+	if err != nil {
+		return err
+	}
+	l.Printf("%s: Running WaitForFailureToPropagate(); details in %s.log", t.failureName, file)
+	if err = failureMode.WaitForFailureToPropagate(ctx, quietLogger, t.args); err != nil {
 		return err
 	}
 
+	l.Printf("validating failure was properly injected")
 	if err = t.validateFailure(ctx, l, c); err != nil {
 		return err
 	}
-	if err = failureMode.Restore(ctx, l, t.args); err != nil {
+
+	quietLogger, file, err = roachtestutil.LoggerForCmd(l, c.CRDBNodes(), t.testName, "restore")
+	if err != nil {
+		return err
+	}
+	l.Printf("%s: Running Restore(); details in %s.log", t.failureName, file)
+	if err = failureMode.Restore(ctx, quietLogger, t.args); err != nil {
 		return err
 	}
 
 	// Allow the cluster to return to normal.
-	if err = failureMode.WaitForFailureToRestore(ctx, l, t.args); err != nil {
+	quietLogger, file, err = roachtestutil.LoggerForCmd(l, c.CRDBNodes(), t.testName, "wait for restore")
+	if err != nil {
+		return err
+	}
+	l.Printf("%s: Running WaitForFailureToRestore(); details in %s.log", t.failureName, file)
+	if err = failureMode.WaitForFailureToRestore(ctx, quietLogger, t.args); err != nil {
 		return err
 	}
 
+	l.Printf("validating failure was properly restored")
 	return t.validateRestore(ctx, l, c)
 }