From 2219f1ec800474778e7e22303975cf0e4c201775 Mon Sep 17 00:00:00 2001
From: Tom Wiesing <tkw01536@gmail.com>
Date: Mon, 3 Oct 2022 13:51:55 +0200
Subject: [PATCH] blind_update: Allow parallel updating

---
 cmd/blind_update.go | 53 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 7 deletions(-)

diff --git a/cmd/blind_update.go b/cmd/blind_update.go
index 5d9dd82..a6e7434 100644
--- a/cmd/blind_update.go
+++ b/cmd/blind_update.go
@@ -1,16 +1,24 @@
 package cmd
 
 import (
+	"fmt"
+	"io"
+
 	wisski_distillery "github.com/FAU-CDI/wisski-distillery"
+	"github.com/FAU-CDI/wisski-distillery/internal/component/instances"
 	"github.com/FAU-CDI/wisski-distillery/internal/core"
 	"github.com/FAU-CDI/wisski-distillery/pkg/environment"
+	"github.com/FAU-CDI/wisski-distillery/pkg/slicesx"
 	"github.com/tkw1536/goprogram/exit"
+	"github.com/tkw1536/goprogram/status"
+	"github.com/tkw1536/goprogram/stream"
 )
 
 // BlindUpdate is the 'blind_update' command
 var BlindUpdate wisski_distillery.Command = blindUpdate{}
 
 type blindUpdate struct {
+	Parallel    int  `short:"p" long:"parallel" description:"run on (at most) this many instances concurrently. 0 for no limit." default:"1"`
 	Force       bool `short:"f" long:"force" description:"force running blind-update even if AutoBlindUpdate is set to false"`
 	Positionals struct {
 		Slug []string `positional-arg-name:"SLUG" required:"0" description:"slug of instance(s) to run blind-update in"`
@@ -33,16 +41,48 @@ var errBlindUpdateFailed = exit.Error{
 }
 
 func (bu blindUpdate) Run(context wisski_distillery.Context) error {
-	instances, err := context.Environment.Instances().Load(bu.Positionals.Slug...)
+	wissKIs, err := context.Environment.Instances().Load(bu.Positionals.Slug...)
 	if err != nil {
 		return err
 	}
+	if !bu.Force {
+		wissKIs = slicesx.Filter(wissKIs, func(instance instances.WissKI) bool {
+			return bool(instance.AutoBlindUpdateEnabled)
+		})
+	}
 
-	for _, instance := range instances {
-		if !(instance.IsBlindUpdateEnabled() || bu.Force) {
-			context.EPrintf("skipping instance %q\n", instance.Slug)
-			continue
-		}
+	if bu.Parallel == 1 {
+		return bu.runSequential(wissKIs, context)
+	}
+
+	return bu.runParallel(wissKIs, context)
+}
+
+func (bu blindUpdate) runParallel(wissKIs []instances.WissKI, context wisski_distillery.Context) error {
+	return status.RunErrorGroup(context.Stdout, status.Group[instances.WissKI, error]{
+		PrefixString: func(item instances.WissKI, index int) string {
+			return fmt.Sprintf("[instance %q]: ", item.Slug)
+		},
+		PrefixAlign: true,
+
+		Handler: func(instance instances.WissKI, index int, writer io.Writer) error {
+			io := stream.NewIOStream(writer, writer, nil, 0)
+
+			code, err := instance.Shell(io, "/runtime/blind_update.sh")
+			if err != nil {
+				return errBlindUpdateFailed.WithMessageF(instance.Slug, environment.ExecCommandError)
+			}
+			if code != 0 {
+				return errBlindUpdateFailed.WithMessageF(instance.Slug, code)
+			}
+			return nil
+		},
+		HandlerLimit: bu.Parallel,
+	}, wissKIs)
+}
+
+func (bu blindUpdate) runSequential(wissKIs []instances.WissKI, context wisski_distillery.Context) error {
+	for _, instance := range wissKIs {
 		context.EPrintf("Updating instance %s\n", instance.Slug)
 
 		code, err := instance.Shell(context.IOStream, "/runtime/blind_update.sh")
@@ -53,6 +93,5 @@ func (bu blindUpdate) Run(context wisski_distillery.Context) error {
 			return errBlindUpdateFailed.WithMessageF(instance.Slug, code)
 		}
 	}
-
 	return nil
 }