frontend: Add instance update functionality

internal/component/instances/wisski_status.go

@@ -21,6 +21,7 @@ type WissKIInfo struct {
 	// Information about the running instance
 	Running     bool
 	LastRebuild time.Time
+	LastUpdate  time.Time
 
 	// List of backups made
 	Snapshots []models.Export
@@ -63,6 +64,10 @@ func (wisski *WissKI) Info(quick bool) (info WissKIInfo, err error) {
 			info.LastRebuild, _ = wisski.LastRebuild()
 			return nil
 		})
+		group.Go(func() (err error) {
+			info.LastUpdate, _ = wisski.LastUpdate()
+			return nil
+		})
 		group.Go(func() error {
 			info.Pathbuilders, _ = wisski.AllPathbuilders()
 			return nil

internal/component/instances/wisski_update.go

@@ -0,0 +1,49 @@
+package instances
+
+import (
+	"time"
+
+	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
+	"github.com/tkw1536/goprogram/exit"
+	"github.com/tkw1536/goprogram/stream"
+)
+
+var errBlindUpdateFailed = exit.Error{
+	Message:  "Failed to run blind update script for instance %q: exited with code %s",
+	ExitCode: exit.ExitGeneric,
+}
+
+// BlinUpdate performs a blind update of the given instance
+func (wisski *WissKI) BlindUpdate(io stream.IOStream) error {
+	code, err := wisski.Shell(io, "/runtime/blind_update.sh")
+	if err != nil {
+		return errBlindUpdateFailed.WithMessageF(wisski.Slug, environment.ExecCommandError)
+	}
+	if code != 0 {
+		return errBlindUpdateFailed.WithMessageF(wisski.Slug, code)
+	}
+
+	return wisski.setLastUpdate()
+}
+
+const KeyLastUpdate MetaKey = "lastUpdate"
+
+func (wisski *WissKI) LastUpdate() (t time.Time, err error) {
+	var epoch int64
+
+	// read the epoch!
+	err = wisski.Metadata().Get(KeyLastUpdate, &epoch)
+	if err == ErrMetadatumNotSet {
+		return t, nil
+	}
+	if err != nil {
+		return t, err
+	}
+
+	// and turn it into time!
+	return time.Unix(epoch, 0), nil
+}
+
+func (wisski *WissKI) setLastUpdate() error {
+	return wisski.Metadata().Set(KeyLastUpdate, time.Now().Unix())
+}