From 5c20ac3f71bddea1dea5993d17009a0cea19b81e Mon Sep 17 00:00:00 2001
From: Heather Lanigan <heather.lanigan@canonical.com>
Date: Wed, 14 Aug 2024 14:44:22 -0400
Subject: [PATCH] fix: add info message when controller does not support backup
 download

Rather than a 404 message, print a nice error message if attempting to
download a backup archive from a 4.0 controller, or any other which does
not support the action.
---
 api/client/backups/download.go | 3 ++-
 cmd/juju/backups/download.go   | 8 ++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/api/client/backups/download.go b/api/client/backups/download.go
index 6b31814af93..47e65ee6d06 100644
--- a/api/client/backups/download.go
+++ b/api/client/backups/download.go
@@ -10,6 +10,7 @@ import (
 	"github.com/juju/errors"
 	"gopkg.in/httprequest.v1"
 
+	apiservererrors "github.com/juju/juju/apiserver/errors"
 	"github.com/juju/juju/rpc/params"
 )
 
@@ -36,7 +37,7 @@ func (c *Client) Download(filename string) (io.ReadCloser, error) {
 		&resp,
 	)
 	if err != nil {
-		return nil, errors.Trace(err)
+		return nil, errors.Trace(apiservererrors.RestoreError(err))
 	}
 	return resp.Body, nil
 }
diff --git a/cmd/juju/backups/download.go b/cmd/juju/backups/download.go
index 9833672190a..510eadfd07b 100644
--- a/cmd/juju/backups/download.go
+++ b/cmd/juju/backups/download.go
@@ -88,9 +88,13 @@ func (c *downloadCommand) Run(ctx *cmd.Context) error {
 	// Download the archive.
 	resultArchive, err := client.Download(c.RemoteFilename)
 	if err != nil {
+		if errors.Is(err, errors.NotFound) {
+			ctx.Errorf("Download of backup archive files is not supported by this controller.")
+			return nil
+		}
 		return errors.Trace(err)
 	}
-	defer resultArchive.Close()
+	defer func() { _ = resultArchive.Close() }()
 
 	// Prepare the local archive.
 	filename := c.ResolveFilename()
@@ -98,7 +102,7 @@ func (c *downloadCommand) Run(ctx *cmd.Context) error {
 	if err != nil {
 		return errors.Annotate(err, "while creating local archive file")
 	}
-	defer archive.Close()
+	defer func() { _ = archive.Close() }()
 
 	// Write out the archive.
 	_, err = io.Copy(archive, resultArchive)