From 78ae826d747faa3b4c4c268c9713d5441f8b1af1 Mon Sep 17 00:00:00 2001
From: CrazyMax <crazy-max@users.noreply.github.com>
Date: Sun, 15 May 2022 08:30:31 +0200
Subject: [PATCH 1/2] ls: dedup instances from store and context

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>
---
 commands/ls.go   | 26 +++++++++++++++++---------
 commands/util.go |  9 +++++++++
 2 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/commands/ls.go b/commands/ls.go
index 15bc6f30..6ca5cd5b 100644
--- a/commands/ls.go
+++ b/commands/ls.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"sort"
 	"strings"
 	"text/tabwriter"
 	"time"
@@ -45,23 +46,30 @@ func runLs(dockerCli command.Cli, in lsOptions) error {
 		builders[i] = &nginfo{ng: ng}
 	}
 
-	list, err := dockerCli.ContextStore().List()
+	contexts, err := dockerCli.ContextStore().List()
 	if err != nil {
 		return err
 	}
-	ctxbuilders := make([]*nginfo, len(list))
-	for i, l := range list {
-		ctxbuilders[i] = &nginfo{ng: &store.NodeGroup{
-			Name: l.Name,
+	sort.Slice(contexts, func(i, j int) bool {
+		return contexts[i].Name < contexts[j].Name
+	})
+	for _, c := range contexts {
+		ngi := &nginfo{ng: &store.NodeGroup{
+			Name: c.Name,
 			Nodes: []store.Node{{
-				Name:     l.Name,
-				Endpoint: l.Name,
+				Name:     c.Name,
+				Endpoint: c.Name,
 			}},
 		}}
+		// if a context has the same name as an instance from the store, do not
+		// add it to the builders list. An instance from the store takes
+		// precedence over context builders.
+		if hasNodeGroup(builders, ngi) {
+			continue
+		}
+		builders = append(builders, ngi)
 	}
 
-	builders = append(builders, ctxbuilders...)
-
 	eg, _ := errgroup.WithContext(ctx)
 
 	for _, b := range builders {
diff --git a/commands/util.go b/commands/util.go
index a75d3420..9d90098e 100644
--- a/commands/util.go
+++ b/commands/util.go
@@ -390,6 +390,15 @@ func loadNodeGroupData(ctx context.Context, dockerCli command.Cli, ngi *nginfo)
 	return nil
 }
 
+func hasNodeGroup(list []*nginfo, ngi *nginfo) bool {
+	for _, l := range list {
+		if ngi.ng.Name == l.ng.Name {
+			return true
+		}
+	}
+	return false
+}
+
 func dockerAPI(dockerCli command.Cli) *api {
 	return &api{dockerCli: dockerCli}
 }

From 69d95cc847e937b447eba6ea91f4aa8bcecab7f9 Mon Sep 17 00:00:00 2001
From: CrazyMax <crazy-max@users.noreply.github.com>
Date: Thu, 19 May 2022 17:17:28 +0200
Subject: [PATCH 2/2] create: warn if instance name already exists as context
 builder

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>
---
 commands/create.go | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/commands/create.go b/commands/create.go
index f946b903..2a9c1296 100644
--- a/commands/create.go
+++ b/commands/create.go
@@ -101,6 +101,19 @@ func runCreate(dockerCli command.Cli, in createOptions, args []string) error {
 		}
 	}
 
+	if !in.actionLeave && !in.actionAppend {
+		contexts, err := dockerCli.ContextStore().List()
+		if err != nil {
+			return err
+		}
+		for _, c := range contexts {
+			if c.Name == name {
+				logrus.Warnf("instance name %q already exists as context builder", name)
+				break
+			}
+		}
+	}
+
 	ng, err := txn.NodeGroupByName(name)
 	if err != nil {
 		if os.IsNotExist(errors.Cause(err)) {