Add historical journald and log export flags to operator debug command (#26410)

* Add -log-file-export and -log-lookback commands to add historical log to
debug capture
* use monitor.PrepFile() helper for other historical log tests

command/agent/monitor/monitor_test.go

@@ -100,14 +100,7 @@ func TestMonitor_Export(t *testing.T) {
 		expectedText = "log log log log log"
 	)
 
-	dir := t.TempDir()
-	f, err := os.CreateTemp(dir, "log")
-	must.NoError(t, err)
-	for range 1000 {
-		_, _ = f.WriteString(fmt.Sprintf("%v [INFO] it's log, it's log, it's big it's heavy it's wood", time.Now()))
-	}
-	f.Close()
-	goldenFilePath := f.Name()
+	goldenFilePath := PrepFile(t).Name()
 	goldenFileContents, err := os.ReadFile(goldenFilePath)
 	must.NoError(t, err)
 

command/agent/monitor/stream_helpers_test.go

@@ -17,27 +17,6 @@ import (
 	"github.com/shoenig/test/must"
 )
 
-var writeLine = []byte("[INFO] log log log made of wood you are heavy but so good\n")
-
-func prepFile(t *testing.T) *os.File {
-	const loopCount = 10
-	// Create test file to read from
-	dir := t.TempDir()
-	f, err := os.CreateTemp(dir, "log")
-	must.NoError(t, err)
-
-	for range loopCount {
-		_, _ = f.Write(writeLine)
-	}
-	f.Close()
-
-	// Create test file reader for stream set up
-	goldenFilePath := f.Name()
-	fileReader, err := os.Open(goldenFilePath)
-	must.NoError(t, err)
-	return fileReader
-}
-
 func TestClientStreamReader_StreamFixed(t *testing.T) {
 	ci.Parallel(t)
 
@@ -80,7 +59,7 @@ func TestClientStreamReader_StreamFixed(t *testing.T) {
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
-			file := prepFile(t)
+			file := PrepFile(t)
 			goldenFileContents, err := os.ReadFile(file.Name())
 			must.NoError(t, err)
 

command/agent/monitor/test_helpers.go

@@ -6,15 +6,19 @@ package monitor
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"net"
+	"os"
 	"strings"
+	"testing"
 	"time"
 
 	"github.com/hashicorp/go-msgpack/v2/codec"
 	sframer "github.com/hashicorp/nomad/client/lib/streamframer"
 	cstructs "github.com/hashicorp/nomad/client/structs"
 	"github.com/hashicorp/nomad/nomad/structs"
+	"github.com/shoenig/test/must"
 )
 
 // StreamingClient is an interface that implements the StreamingRpcHandler function
@@ -22,6 +26,27 @@ type StreamingClient interface {
 	StreamingRpcHandler(string) (structs.StreamingRpcHandler, error)
 }
 
+var writeLine = []byte(fmt.Sprintf("[INFO] log log log made of wood you are heavy but so good, %v\n", time.Now()))
+
+func PrepFile(t *testing.T) *os.File {
+	const loopCount = 100
+	// Create test file to read from
+	dir := t.TempDir()
+	f, err := os.CreateTemp(dir, "log")
+	must.NoError(t, err)
+
+	for range loopCount {
+		_, _ = f.Write(writeLine)
+	}
+	f.Close()
+
+	// Create test file reader for stream set up
+	goldenFilePath := f.Name()
+	fileReader, err := os.Open(goldenFilePath)
+	must.NoError(t, err)
+	return fileReader
+}
+
 // ExportMonitorClient_TestHelper consolidates streaming test setup for use in
 // client and server RPChandler tests
 func ExportMonitorClient_TestHelper(req cstructs.MonitorExportRequest, c StreamingClient,