Files
docker-cli/cli/command/image/save.go
Sebastiaan van Stijn 531f7e121d cli/command/completion: change Platforms to return a cobra.CompletionFunc
It's adding a slight indirection by constructing a function when called,
but makes the completion functions more consistent, the signature easier
to read, and making the return type a [cobra.CompletionFunc] makes it
more transparent what it's intended for, and helps discovery of functions
that provide completion.

[cobra.CompletionFunc]: https://pkg.go.dev/github.com/spf13/cobra#CompletionFunc

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2025-09-10 12:06:42 +02:00

94 lines
2.6 KiB
Go

package image
import (
"context"
"errors"
"fmt"
"io"
"github.com/containerd/platforms"
"github.com/docker/cli/cli"
"github.com/docker/cli/cli/command"
"github.com/docker/cli/cli/command/completion"
"github.com/moby/moby/client"
"github.com/moby/sys/atomicwriter"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/spf13/cobra"
)
type saveOptions struct {
images []string
output string
platform []string
}
// newSaveCommand creates a new "docker image save" command.
func newSaveCommand(dockerCLI command.Cli) *cobra.Command {
var opts saveOptions
cmd := &cobra.Command{
Use: "save [OPTIONS] IMAGE [IMAGE...]",
Short: "Save one or more images to a tar archive (streamed to STDOUT by default)",
Args: cli.RequiresMinArgs(1),
RunE: func(cmd *cobra.Command, args []string) error {
opts.images = args
return runSave(cmd.Context(), dockerCLI, opts)
},
Annotations: map[string]string{
"aliases": "docker image save, docker save",
},
ValidArgsFunction: completion.ImageNames(dockerCLI, -1),
DisableFlagsInUseLine: true,
}
flags := cmd.Flags()
flags.StringVarP(&opts.output, "output", "o", "", "Write to a file, instead of STDOUT")
flags.StringSliceVar(&opts.platform, "platform", []string{}, `Save only the given platform(s). Formatted as a comma-separated list of "os[/arch[/variant]]" (e.g., "linux/amd64,linux/arm64/v8")`)
_ = flags.SetAnnotation("platform", "version", []string{"1.48"})
_ = cmd.RegisterFlagCompletionFunc("platform", completion.Platforms())
return cmd
}
// runSave performs a save against the engine based on the specified options
func runSave(ctx context.Context, dockerCLI command.Cli, opts saveOptions) error {
var options []client.ImageSaveOption
platformList := []ocispec.Platform{}
for _, p := range opts.platform {
pp, err := platforms.Parse(p)
if err != nil {
return fmt.Errorf("invalid platform: %w", err)
}
platformList = append(platformList, pp)
}
if len(platformList) > 0 {
options = append(options, client.ImageSaveWithPlatforms(platformList...))
}
var output io.Writer
if opts.output == "" {
if dockerCLI.Out().IsTerminal() {
return errors.New("cowardly refusing to save to a terminal. Use the -o flag or redirect")
}
output = dockerCLI.Out()
} else {
writer, err := atomicwriter.New(opts.output, 0o600)
if err != nil {
return fmt.Errorf("failed to save image: %w", err)
}
defer writer.Close()
output = writer
}
responseBody, err := dockerCLI.Client().ImageSave(ctx, opts.images, options...)
if err != nil {
return err
}
defer responseBody.Close()
_, err = io.Copy(output, responseBody)
return err
}