remove excel for csv

Signed-off-by: Luke Roy <luke.roy@ibm.com>
Luke-Roy-IBM · Apr 22, 2026 · Apr 22, 2026 · Apr 22, 2026 · Apr 22, 2026 · Apr 22, 2026
commit 3987b2ce626b557f920afa3fbc800a0468d59a24
diff --git a/serverless-fleet-worker-registration/.dockerignore b/serverless-fleet-worker-registration/.dockerignore
@@ -10,8 +10,7 @@ fleet-register
 *_test.go
 
 # Output files
-*.xlsx
-*.xls
+*.csv
 
 # Git
 .git

diff --git a/serverless-fleet-worker-registration/Dockerfile b/serverless-fleet-worker-registration/Dockerfile
@@ -32,8 +32,8 @@ EXPOSE 8080
 
 RUN mkdir /fleet-workers
 
-# Set environment variable for the workbook path
-ENV WORKBOOK_PATH=/fleet-workers/fleet-register.xlsx
+# Set environment variable for the CSV path
+ENV CSV_PATH=/fleet-workers/fleet-register.csv
 
 # Run the application
 CMD ["/app/fleet-register"]
diff --git a/serverless-fleet-worker-registration/README.md b/serverless-fleet-worker-registration/README.md
@@ -1,10 +1,10 @@
 # Fleet Register
 
-A lightweight Go HTTP server that monitors IBM Cloud Code Engine fleet workers by tracking their lifecycle events in an Excel file.
+A lightweight Go HTTP server that monitors IBM Cloud Code Engine fleet workers by tracking their lifecycle events in a CSV file.
 
 ## Use Case
 
-This application is deployed as a Code Engine application to monitor fleet workers. Fleet workers call the `/register` endpoint when they start and the `/deregister` endpoint before they shut down. The application maintains a persistent Excel file tracking all worker activity, including registration and completion timestamps.
+This application is deployed as a Code Engine application to monitor fleet workers. Fleet workers call the `/register` endpoint when they start and the `/deregister` endpoint before they shut down. The application maintains a persistent CSV file tracking all worker activity, including registration and completion timestamps.
 
 **Deployment Flow:**
 1. Deploy this app as a Code Engine application with persistent storage
@@ -14,14 +14,14 @@ This application is deployed as a Code Engine application to monitor fleet worke
 ## Endpoints
 
 - `POST /register`
-  Creates a row in `fleet-register.xlsx` with status `running` and records the registration timestamp.
+  Creates a row in `fleet-register.csv` with status `running` and records the registration timestamp.
 
 - `POST /deregister`
   Updates the matching row by `worker_name` and `worker_ip` to `completed` and records the completion timestamp.
   If no row exists, it creates a new row with status `completed`.
 
 - `GET /download`
-  Downloads the Excel file.
+  Downloads the CSV file.
 
 ## Request body
 
@@ -93,7 +93,7 @@ docker build -t fleet-register .
 docker run -p 8080:8080 -v fleet-data:/fleet-workers fleet-register
 ```
 
-The Excel file is saved to `/fleet-workers/fleet-register.xlsx` and persisted in the volume.
+The CSV file is saved to `/fleet-workers/fleet-register.csv` and persisted in the volume.
 
 ## Examples
 
@@ -119,17 +119,17 @@ curl -X POST http://localhost:8080/deregister \
   }'
 ```
 
-Download the workbook:
+Download the CSV file:
 
 ```bash
 curl -O -J http://localhost:8080/download
 ```
 
-## Excel file
+## CSV file
 
-The server automatically creates `fleet-register.xlsx` in the project root (or `/fleet-workers/` in Docker) if it does not exist.
+The server automatically creates `fleet-register.csv` in the project root (or `/fleet-workers/` in Docker) if it does not exist.
 
-The workbook contains one sheet named `Workers` with these columns:
+The CSV file contains the following columns:
 
 - `worker_name` - Name of the worker
 - `worker_ip` - IP address of the worker

diff --git a/serverless-fleet-worker-registration/go.mod b/serverless-fleet-worker-registration/go.mod
@@ -1,16 +1,3 @@
 module fleet-register
 
 go 1.22
-
-require github.com/xuri/excelize/v2 v2.8.1
-
-require (
-	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
-	github.com/richardlehane/mscfb v1.0.4 // indirect
-	github.com/richardlehane/msoleps v1.0.3 // indirect
-	github.com/xuri/efp v0.0.0-20231025114914-d1ff6096ae53 // indirect
-	github.com/xuri/nfp v0.0.0-20230919160717-d98342af3f05 // indirect
-	golang.org/x/crypto v0.19.0 // indirect
-	golang.org/x/net v0.21.0 // indirect
-	golang.org/x/text v0.14.0 // indirect
-)
diff --git a/serverless-fleet-worker-registration/main.go b/serverless-fleet-worker-registration/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/csv"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -10,25 +11,22 @@ import (
 	"strings"
 	"sync"
 	"time"
-
-	"github.com/xuri/excelize/v2"
 )
 
 const (
 	serverAddr = ":8080"
-	sheetName  = "Workers"
 )
 
-var workbookPath = getWorkbookPath()
+var csvPath = getCSVPath()
 
-func getWorkbookPath() string {
-	if path := os.Getenv("WORKBOOK_PATH"); path != "" {
+func getCSVPath() string {
+	if path := os.Getenv("CSV_PATH"); path != "" {
 		return path
 	}
-	return "fleet-register.xlsx"
+	return "fleet-register.csv"
 }
 
-var workbookMu sync.Mutex
+var csvMu sync.Mutex
 
 type workerRequest struct {
 	WorkerName string `json:"worker_name"`
@@ -64,8 +62,8 @@ func registerHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	workbookMu.Lock()
-	defer workbookMu.Unlock()
+	csvMu.Lock()
+	defer csvMu.Unlock()
 
 	if err := appendWorkerRow(req, "running"); err != nil {
 		writeError(w, http.StatusInternalServerError, fmt.Sprintf("failed to register worker: %v", err))
@@ -77,7 +75,7 @@ func registerHandler(w http.ResponseWriter, r *http.Request) {
 		WorkerName: req.WorkerName,
 		WorkerIP:   req.WorkerIP,
 		Status:     "running",
-		File:       workbookPath,
+		File:       csvPath,
 	})
 }
 
@@ -88,8 +86,8 @@ func deregisterHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	workbookMu.Lock()
-	defer workbookMu.Unlock()
+	csvMu.Lock()
+	defer csvMu.Unlock()
 
 	updated, err := completeWorker(req)
 	if err != nil {
@@ -107,27 +105,27 @@ func deregisterHandler(w http.ResponseWriter, r *http.Request) {
 		WorkerName: req.WorkerName,
 		WorkerIP:   req.WorkerIP,
 		Status:     "completed",
-		File:       workbookPath,
+		File:       csvPath,
 	})
 }
 
 func downloadHandler(w http.ResponseWriter, r *http.Request) {
-	workbookMu.Lock()
-	defer workbookMu.Unlock()
+	csvMu.Lock()
+	defer csvMu.Unlock()
 
-	if err := ensureWorkbook(); err != nil {
-		writeError(w, http.StatusInternalServerError, fmt.Sprintf("failed to prepare workbook: %v", err))
+	if err := ensureCSV(); err != nil {
+		writeError(w, http.StatusInternalServerError, fmt.Sprintf("failed to prepare CSV: %v", err))
 		return
 	}
 
-	content, err := os.ReadFile(workbookPath)
+	content, err := os.ReadFile(csvPath)
 	if err != nil {
-		writeError(w, http.StatusInternalServerError, fmt.Sprintf("failed to read workbook: %v", err))
+		writeError(w, http.StatusInternalServerError, fmt.Sprintf("failed to read CSV: %v", err))
 		return
 	}
 
-	w.Header().Set("Content-Type", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
-	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, workbookPath))
+	w.Header().Set("Content-Type", "text/csv")
+	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, csvPath))
 	w.Header().Set("Content-Length", fmt.Sprintf("%d", len(content)))
 	w.WriteHeader(http.StatusOK)
 
@@ -159,133 +157,98 @@ func decodeWorkerRequest(r *http.Request) (workerRequest, error) {
 }
 
 func appendWorkerRow(req workerRequest, status string) error {
-	file, err := openWorkbook()
-	if err != nil {
+	if err := ensureCSV(); err != nil {
 		return err
 	}
-	defer closeWorkbook(file)
 
-	rows, err := file.GetRows(sheetName)
+	file, err := os.OpenFile(csvPath, os.O_APPEND|os.O_WRONLY, 0644)
 	if err != nil {
 		return err
 	}
+	defer file.Close()
 
-	nextRow := len(rows) + 1
-	registeredAt := time.Now().Format(time.RFC3339)
-	values := []interface{}{req.WorkerName, req.WorkerIP, status, registeredAt, ""}
-
-	cell, err := excelize.CoordinatesToCellName(1, nextRow)
-	if err != nil {
-		return err
-	}
+	writer := csv.NewWriter(file)
+	defer writer.Flush()
 
-	if err := file.SetSheetRow(sheetName, cell, &values); err != nil {
-		return err
-	}
+	registeredAt := time.Now().Format(time.RFC3339)
+	record := []string{req.WorkerName, req.WorkerIP, status, registeredAt, ""}
 
-	return file.SaveAs(workbookPath)
+	return writer.Write(record)
 }
 
 func completeWorker(req workerRequest) (bool, error) {
-	file, err := openWorkbook()
+	if err := ensureCSV(); err != nil {
+		return false, err
+	}
+
+	// Read all records
+	file, err := os.Open(csvPath)
 	if err != nil {
 		return false, err
 	}
-	defer closeWorkbook(file)
 
-	rows, err := file.GetRows(sheetName)
+	reader := csv.NewReader(file)
+	records, err := reader.ReadAll()
+	file.Close()
 	if err != nil {
 		return false, err
 	}
 
 	completedAt := time.Now().Format(time.RFC3339)
-
-	for index := 1; index < len(rows); index++ {
-		row := rows[index]
-		if len(row) < 2 {
-			continue
-		}
-
-		if row[0] == req.WorkerName && row[1] == req.WorkerIP {
-			// Update status to completed (column 3)
-			statusCell, err := excelize.CoordinatesToCellName(3, index+1)
-			if err != nil {
-				return false, err
-			}
-
-			if err := file.SetCellValue(sheetName, statusCell, "completed"); err != nil {
-				return false, err
-			}
-
-			// Update completed_at timestamp (column 5)
-			completedCell, err := excelize.CoordinatesToCellName(5, index+1)
-			if err != nil {
-				return false, err
-			}
-
-			if err := file.SetCellValue(sheetName, completedCell, completedAt); err != nil {
-				return false, err
-			}
-
-			return true, file.SaveAs(workbookPath)
+	updated := false
+
+	// Update matching record
+	for i := 1; i < len(records); i++ {
+		if len(records[i]) >= 2 && records[i][0] == req.WorkerName && records[i][1] == req.WorkerIP {
+			records[i][2] = "completed"
+			records[i][4] = completedAt
+			updated = true
+			break
 		}
 	}
 
-	// If worker not found, add new row with completed status
-	values := []interface{}{req.WorkerName, req.WorkerIP, "completed", "", completedAt}
-	nextRow := len(rows) + 1
+	// If not found, add new record
+	if !updated {
+		records = append(records, []string{req.WorkerName, req.WorkerIP, "completed", "", completedAt})
+	}
 
-	cell, err := excelize.CoordinatesToCellName(1, nextRow)
+	// Write all records back
+	file, err = os.Create(csvPath)
 	if err != nil {
 		return false, err
 	}
+	defer file.Close()
 
-	if err := file.SetSheetRow(sheetName, cell, &values); err != nil {
-		return false, err
+	writer := csv.NewWriter(file)
+	defer writer.Flush()
+
+	for _, record := range records {
+		if err := writer.Write(record); err != nil {
+			return false, err
+		}
 	}
 
-	return false, file.SaveAs(workbookPath)
+	return updated, nil
 }
 
-func ensureWorkbook() error {
-	if _, err := os.Stat(workbookPath); err == nil {
+func ensureCSV() error {
+	if _, err := os.Stat(csvPath); err == nil {
 		return nil
 	} else if !os.IsNotExist(err) {
 		return err
 	}
 
-	file := excelize.NewFile()
-	defaultSheet := file.GetSheetName(file.GetActiveSheetIndex())
-
-	if defaultSheet != sheetName {
-		file.SetSheetName(defaultSheet, sheetName)
-	}
-
-	headers := []interface{}{"worker_name", "worker_ip", "status", "registered_at", "completed_at"}
-	if err := file.SetSheetRow(sheetName, "A1", &headers); err != nil {
-		return err
-	}
-
-	return file.SaveAs(workbookPath)
-}
-
-func openWorkbook() (*excelize.File, error) {
-	if err := ensureWorkbook(); err != nil {
-		return nil, err
-	}
-
-	file, err := excelize.OpenFile(workbookPath)
+	file, err := os.Create(csvPath)
 	if err != nil {
-		return nil, err
+		return err
 	}
+	defer file.Close()
 
-	return file, nil
-}
+	writer := csv.NewWriter(file)
+	defer writer.Flush()
 
-func closeWorkbook(file *excelize.File) {
-	if err := file.Close(); err != nil {
-		log.Printf("failed to close workbook: %v", err)
-	}
+	headers := []string{"worker_name", "worker_ip", "status", "registered_at", "completed_at"}
+	return writer.Write(headers)
 }
 
 func writeJSON(w http.ResponseWriter, statusCode int, payload apiResponse) {
-Original file line number
+Diff line change
@@ Expand Up / @@ -10,8 +10,7 @@ fleet-register @@
     *_test.go
     # Output files
-    *.xlsx
-    *.xls
+    *.csv
     # Git
     .git
@@ Expand Down @@