Add optional status report file (-r) for external tooling

cmd/modd/main.go

@@ -8,13 +8,15 @@ import (
 
 	"github.com/cortesi/modd"
 	"github.com/cortesi/modd/notify"
+	"github.com/cortesi/modd/report"
 	"github.com/cortesi/termlog"
 	"gopkg.in/alecthomas/kingpin.v2"
 	"mvdan.cc/sh/v3/interp"
 	"mvdan.cc/sh/v3/syntax"
 )
 
 const modfile = "./modd.conf"
+const reportFile = ".modd_report"
 
 var file = kingpin.Flag(
 	"file",
@@ -41,6 +43,10 @@ var doNotify = kingpin.Flag("notify", "Send stderr to system notification if com
 	Short('n').
 	Bool()
 
+var doReport = kingpin.Flag("report", "Report last prep status to file").
+	Short('r').
+	Bool()
+
 var prep = kingpin.Flag("prep", "Run prep commands and exit").
 	Short('p').
 	Bool()
@@ -109,7 +115,15 @@ func main() {
 		notifiers = append(notifiers, &notify.BeepNotifier{})
 	}
 
-	mr, err := modd.NewModRunner(*file, log, notifiers, !(*noconf))
+	reporters := []report.Reporter{}
+	if *doReport {
+		r := report.FileReporter{
+			Filename: reportFile,
+		}
+		reporters = append(reporters, r)
+	}
+
+	mr, err := modd.NewModRunner(*file, log, notifiers, reporters, !(*noconf))
 	if err != nil {
 		log.Shout("%s", err)
 		return

conf/conf.go

@@ -27,6 +27,8 @@ type Block struct {
 
 	Daemons []Daemon
 	Preps   []Prep
+
+	Status int
 }
 
 func (b *Block) addPrep(command string, options []string) error {

modd.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/cortesi/modd/conf"
 	"github.com/cortesi/modd/notify"
+	"github.com/cortesi/modd/report"
 	"github.com/cortesi/modd/shell"
 	"github.com/cortesi/moddwatch"
 	"github.com/cortesi/termlog"
@@ -58,15 +59,17 @@ type ModRunner struct {
 	ConfPath   string
 	ConfReload bool
 	Notifiers  []notify.Notifier
+	Reporters  []report.Reporter
 }
 
 // NewModRunner constructs a new ModRunner
-func NewModRunner(confPath string, log termlog.TermLog, notifiers []notify.Notifier, confreload bool) (*ModRunner, error) {
+func NewModRunner(confPath string, log termlog.TermLog, notifiers []notify.Notifier, reporters []report.Reporter, confreload bool) (*ModRunner, error) {
 	mr := &ModRunner{
 		Log:        log,
 		ConfPath:   confPath,
 		ConfReload: confreload,
 		Notifiers:  notifiers,
+		Reporters:  reporters,
 	}
 	err := mr.ReadConfig()
 	if err != nil {
@@ -106,12 +109,12 @@ func (mr *ModRunner) PrepOnly(initial bool) error {
 	return nil
 }
 
-func (mr *ModRunner) runBlock(b conf.Block, mod *moddwatch.Mod, dpen *DaemonPen) {
+func (mr *ModRunner) runBlock(b conf.Block, mod *moddwatch.Mod, dpen *DaemonPen) error {
 	if b.InDir != "" {
 		currentDir, err := os.Getwd()
 		if err != nil {
 			mr.Log.Shout("Error getting current working directory: %s", err)
-			return
+			return err
 		}
 		err = os.Chdir(b.InDir)
 		if err != nil {
@@ -120,7 +123,7 @@ func (mr *ModRunner) runBlock(b conf.Block, mod *moddwatch.Mod, dpen *DaemonPen)
 				b.InDir,
 				err,
 			)
-			return
+			return err
 		}
 		defer func() {
 			err := os.Chdir(currentDir)
@@ -140,9 +143,10 @@ func (mr *ModRunner) runBlock(b conf.Block, mod *moddwatch.Mod, dpen *DaemonPen)
 		if _, ok := err.(ProcError); !ok {
 			mr.Log.Shout("Error running prep: %s", err)
 		}
-		return
+		return err
 	}
 	dpen.Restart()
+	return nil
 }
 
 func (mr *ModRunner) trigger(root string, mod *moddwatch.Mod, dworld *DaemonWorld) {
@@ -159,7 +163,28 @@ func (mr *ModRunner) trigger(root string, mod *moddwatch.Mod, dworld *DaemonWorl
 				continue
 			}
 		}
-		mr.runBlock(b, lmod, dworld.DaemonPens[i])
+
+		err := mr.runBlock(b, lmod, dworld.DaemonPens[i])
+
+		if err != nil {
+			mr.Config.Blocks[i].Status = 1
+		} else {
+			mr.Config.Blocks[i].Status = 0
+		}
+	}
+
+	// Compute overall status: != 0 if any block has Status != 0, otherwise 0.
+	status := 0
+
+	for _, b := range mr.Config.Blocks {
+		if status == 0 {
+			status = b.Status
+		}
+	}
+
+	// Report the overall status to all reporters.
+	for _, r := range mr.Reporters {
+		r.Report(time.Now(), status)
 	}
 }
 

report/reporter.go

@@ -0,0 +1,38 @@
+package report
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+// Reporter publishes status updates.
+type Reporter interface {
+	Report(timestamp time.Time, status int)
+}
+
+// FileReporter writes status updates to a file.
+type FileReporter struct {
+	Filename string
+}
+
+// Report implements the Reporter interface.
+func (fs FileReporter) Report(timestamp time.Time, status int) {
+	ts := time.Now().UTC().Format(time.RFC3339)
+	msg := fmt.Sprintf("%s,%d\n", ts, status)
+
+	// Open for write, create if missing, truncate to zero length.
+	f, err := os.OpenFile(fs.Filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
+	if err != nil {
+		return
+	}
+	defer f.Close()
+
+	if _, err := f.Write([]byte(msg)); err != nil {
+		return
+	}
+
+	if err := f.Sync(); err != nil {
+		return
+	}
+}