configurable log writer

Signed-off-by: razzle <harry@razzle.cloud>

src/pkg/message/credentials.go

@@ -6,7 +6,6 @@ package message
 
 import (
 	"fmt"
-	"os"
 	"strings"
 
 	"github.com/defenseunicorns/zarf/src/config"
@@ -31,8 +30,7 @@ func PrintCredentialTable(state *types.ZarfState, componentsToDeploy []types.Dep
 		componentsToDeploy = []types.DeployedComponent{{Name: "logging"}, {Name: "git-server"}}
 	}
 
-	// Set output to os.Stderr to avoid creds being printed in logs
-	pterm.SetDefaultOutput(os.Stderr)
+	MultLogger.DisableLogFile()
 
 	loginData := [][]string{}
 	if state.RegistryInfo.InternalRegistry {
@@ -64,7 +62,7 @@ func PrintCredentialTable(state *types.ZarfState, componentsToDeploy []types.Dep
 
 	// Restore the log file if it was specified
 	if !config.SkipLogFile {
-		UseLogFile()
+		MultLogger.EnableLogFile()
 	}
 }
 
@@ -96,8 +94,7 @@ func PrintComponentCredential(state *types.ZarfState, componentName string) {
 
 // PrintCredentialUpdates displays credentials that will be updated
 func PrintCredentialUpdates(oldState *types.ZarfState, newState *types.ZarfState, services []string) {
-	// Set output to os.Stderr to avoid creds being printed in logs
-	pterm.SetDefaultOutput(os.Stderr)
+	MultLogger.DisableLogFile()
 
 	for _, service := range services {
 
@@ -147,7 +144,7 @@ func PrintCredentialUpdates(oldState *types.ZarfState, newState *types.ZarfState
 
 	// Restore the log file if it was specified
 	if !config.SkipLogFile {
-		UseLogFile()
+		MultLogger.EnableLogFile()
 	}
 }
 

src/pkg/message/generic.go

@@ -4,7 +4,12 @@
 // Package message provides a rich set of functions for displaying messages to the user.
 package message
 
-import "github.com/pterm/pterm"
+import (
+	"io"
+	"os"
+
+	"github.com/pterm/pterm"
+)
 
 // Generic is used to implement the io.Writer interface for generic messages.
 type Generic struct{}
@@ -14,3 +19,47 @@ func (g *Generic) Write(p []byte) (n int, err error) {
 	pterm.Println(text)
 	return len(p), nil
 }
+
+// MultiLogWriter is an implementation of an io.Writer that writes to both a file and a writer.
+//
+// This is useful for writing to both a log file and the terminal at the same time.
+//
+// While maintaining the ability to disable one or the other as needed.
+//
+// This struct is NOT thread-safe and should normally be a global singleton.
+type MultiLogWriter struct {
+	f     *os.File
+	wr    io.Writer
+	multi io.Writer
+}
+
+// NewMultiLogWriter creates a new MultiLogWriter instance.
+func NewMultiLogWriter(f *os.File, wr io.Writer) *MultiLogWriter {
+	multi := io.MultiWriter(f, wr)
+	return &MultiLogWriter{f, wr, multi}
+}
+
+// DisableLogFile disables the log file writer.
+func (l *MultiLogWriter) DisableLogFile() {
+	l.multi = l.wr
+}
+
+// EnableLogFile enables the log file writer.
+func (l *MultiLogWriter) EnableLogFile() {
+	l.multi = io.MultiWriter(l.f, l.wr)
+}
+
+// DisableWriter disables the writer.
+func (l *MultiLogWriter) DisableWriter() {
+	l.multi = l.f
+}
+
+// EnableWriter enables the writer.
+func (l *MultiLogWriter) EnableWriter() {
+	l.multi = io.MultiWriter(l.f, l.wr)
+}
+
+// Write writes to the multi writer. Satisfaction of the io.Writer interface.
+func (l *MultiLogWriter) Write(p []byte) (n int, err error) {
+	return l.multi.Write(p)
+}

src/pkg/message/message.go

@@ -7,7 +7,6 @@ package message
 import (
 	"encoding/json"
 	"fmt"
-	"io"
 	"net/http"
 	"os"
 	"runtime/debug"
@@ -44,14 +43,11 @@ var NoProgress bool
 // RuleLine creates a line of ━ as wide as the terminal
 var RuleLine = strings.Repeat("━", TermWidth)
 
-// LogWriter is the stream to write logs to.
-var LogWriter io.Writer = os.Stderr
-
 // logLevel holds the pterm compatible log level integer
 var logLevel = InfoLevel
 
-// logFile acts as a buffer for logFile generation
-var logFile *os.File
+// MultLogger acts as a buffer for MultLogger generation
+var MultLogger *MultiLogWriter
 
 // useLogFile controls whether to use the log file or not
 var useLogFile bool
@@ -84,26 +80,24 @@ func init() {
 
 // UseLogFile writes output to stderr and a logFile.
 func UseLogFile() {
+	// If a log file has already been created, don't create another one
+	if MultLogger != nil {
+		return
+	}
 	// Prepend the log filename with a timestamp.
 	ts := time.Now().Format("2006-01-02-15-04-05")
 
-	var err error
-	if logFile != nil {
-		// Use the existing log file if logFile is set
-		LogWriter = io.MultiWriter(os.Stderr, logFile)
-		pterm.SetDefaultOutput(LogWriter)
-	} else {
-		// Try to create a temp log file if one hasn't been made already
-		if logFile, err = os.CreateTemp("", fmt.Sprintf("zarf-%s-*.log", ts)); err != nil {
-			WarnErr(err, "Error saving a log file to a temporary directory")
-		} else {
-			useLogFile = true
-			LogWriter = io.MultiWriter(os.Stderr, logFile)
-			pterm.SetDefaultOutput(LogWriter)
-			message := fmt.Sprintf("Saving log file to %s", logFile.Name())
-			Note(message)
-		}
+	// Try to create a temp log file if one hasn't been made already
+	logFile, err := os.CreateTemp("", fmt.Sprintf("zarf-%s-*.log", ts))
+	if err != nil {
+		WarnErr(err, "Error saving a log file to a temporary directory")
 	}
+
+	MultLogger = NewMultiLogWriter(logFile, os.Stderr)
+
+	pterm.SetDefaultOutput(MultLogger)
+	message := fmt.Sprintf("Saving log file to %s", logFile.Name())
+	Note(message)
 }
 
 // SetLogLevel sets the log level.
@@ -371,7 +365,7 @@ func debugPrinter(offset int, a ...any) {
 			WithShowLineNumber(true).
 			WithLineNumberOffset(offset).
 			WithDebugger(false).
-			WithWriter(logFile).
+			WithWriter(MultLogger).
 			Println(a...)
 	}
 }