fix: add info message when controller does not support backup download

hmlanigan · hmlanigan · commit 5c20ac3f71bd · 2024-08-14T15:04:11.000-04:00
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.
diff --git 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
@@ -88,17 +88,21 @@ 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()
 	archive, err := c.Filesystem().Create(filename)
 	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)

Original file line number	Diff line number	Diff line change
`@@ -10,6 +10,7 @@ import (`
`10`	`10`	`"github.com/juju/errors"`
`11`	`11`	`"gopkg.in/httprequest.v1"`
`12`	`12`
	`13`	`+ apiservererrors "github.com/juju/juju/apiserver/errors"`
`13`	`14`	`"github.com/juju/juju/rpc/params"`
`14`	`15`	`)`
`15`	`16`
`@@ -36,7 +37,7 @@ func (c *Client) Download(filename string) (io.ReadCloser, error) {`
`36`	`37`	`&resp,`
`37`	`38`	`)`
`38`	`39`	`if err != nil {`
`39`		`- return nil, errors.Trace(err)`
	`40`	`+ return nil, errors.Trace(apiservererrors.RestoreError(err))`
`40`	`41`	`}`
`41`	`42`	`return resp.Body, nil`
`42`	`43`	`}`