Hallucinate a basic cronjob interface

crontabd/go.mod

@@ -5,6 +5,7 @@ go 1.23.6
 require (
 	git.site.quack-lab.dev/dave/cylogger v1.2.3
 	github.com/fsnotify/fsnotify v1.9.0
+	github.com/robfig/cron/v3 v3.0.1
 )
 
 require golang.org/x/sys v0.13.0 // indirect

crontabd/go.sum

@@ -2,5 +2,7 @@ git.site.quack-lab.dev/dave/cylogger v1.2.3 h1:g6fwgrd3HvGsxljvKbjcFaMynTO2AZFWj
 git.site.quack-lab.dev/dave/cylogger v1.2.3/go.mod h1:sf16Zs5ZRncn0ySgwxRJShkge1M10CM2RAUkKn8Bel8=
 github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
 github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
+github.com/robfig/cron/v3 v3.0.1 h1:WdRxkvbJztn8LMz/QEvLN5sBU+xKpSqwwUO1Pjr4qDs=
+github.com/robfig/cron/v3 v3.0.1/go.mod h1:eQICP3HwyT7UooqI/z+Ov+PtYAWygg1TEWWzGIFLtro=
 golang.org/x/sys v0.13.0 h1:Af8nKPmuFypiUBjVoU9V20FiaFXOcuZI21p0ycVYYGE=
 golang.org/x/sys v0.13.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

crontabd/main.go

@@ -4,9 +4,12 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"strings"
 
 	"github.com/fsnotify/fsnotify"
+	"github.com/robfig/cron/v3"
 
 	logger "git.site.quack-lab.dev/dave/cylogger"
 )
@@ -17,6 +20,7 @@ type CronJob struct {
 }
 
 var crontabFile string
+var cronRunner *cron.Cron
 
 func main() {
 	flag.Parse()
@@ -36,6 +40,20 @@ func main() {
 	}
 	logger.Info("Crontab file resolved as: %s", crontabFile)
 
+	// Initialize cron runner with seconds disabled (standard cron format)
+	cronRunner = cron.New()
+	defer cronRunner.Stop()
+
+	// Load initial cron jobs
+	if err := loadCronJobs(); err != nil {
+		logger.Error("Failed to load initial cron jobs: %v", err)
+		return
+	}
+
+	// Start the cron scheduler
+	cronRunner.Start()
+	logger.Info("Cron scheduler started")
+
 	events, err := watchCrontabFile(crontabFile)
 	if err != nil {
 		logger.Error("Failed to watch crontab file: %v", err)
@@ -43,6 +61,73 @@ func main() {
 	}
 	for event := range events {
 		logger.Info("Crontab file updated: %s", event.Name)
+		// Reload cron jobs when file changes
+		if err := loadCronJobs(); err != nil {
+			logger.Error("Failed to reload cron jobs: %v", err)
+		}
+	}
+}
+
+func loadCronJobs() error {
+	// Read the crontab file
+	content, err := os.ReadFile(crontabFile)
+	if err != nil {
+		return fmt.Errorf("failed to read crontab file: %v", err)
+	}
+
+	// Stop current jobs
+	cronRunner.Stop()
+	// Create new cron runner
+	cronRunner = cron.New()
+
+	// Parse each line
+	lines := strings.Split(string(content), "\n")
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+
+		// Split into cron expression and command
+		fields := strings.Fields(line)
+		if len(fields) < 6 {
+			logger.Error("Invalid cron line: %s", line)
+			continue
+		}
+
+		cronExpr := strings.Join(fields[0:5], " ")
+		cmdStr := strings.Join(fields[5:], " ")
+
+		job := CronJob{
+			Cron:    cronExpr,
+			Command: cmdStr,
+		}
+
+		// Add the job to cron
+		_, err := cronRunner.AddFunc(job.Cron, createJobFunc(job))
+		if err != nil {
+			logger.Error("Failed to add cron job %+v: %v", job, err)
+			continue
+		}
+		logger.Info("Added cron job: %s -> %s", job.Cron, job.Command)
+	}
+
+	// Start the cron scheduler
+	cronRunner.Start()
+	return nil
+}
+
+func createJobFunc(job CronJob) func() {
+	return func() {
+		cmd := exec.Command("sh", "-c", job.Command)
+		output, err := cmd.CombinedOutput()
+		if err != nil {
+			logger.Error("Failed to execute command '%s': %v", job.Command, err)
+			logger.Error("Command output: %s", string(output))
+			return
+		}
+		logger.Info("Successfully executed command '%s'", job.Command)
+		logger.Info("Command output: %s", string(output))
 	}
 }