github.com/AliyunContainerService/cli@v0.0.0-20181009023821-814ced4b30d0/cli/command/image/pull.go (about)

     1  package image
     2  
     3  import (
     4  	"context"
     5  	"fmt"
     6  	"strings"
     7  
     8  	"github.com/docker/cli/cli"
     9  	"github.com/docker/cli/cli/command"
    10  	"github.com/docker/cli/cli/trust"
    11  	"github.com/docker/distribution/reference"
    12  	"github.com/pkg/errors"
    13  	"github.com/spf13/cobra"
    14  )
    15  
    16  // PullOptions defines what and how to pull
    17  type PullOptions struct {
    18  	remote    string
    19  	all       bool
    20  	platform  string
    21  	untrusted bool
    22  }
    23  
    24  // NewPullCommand creates a new `docker pull` command
    25  func NewPullCommand(dockerCli command.Cli) *cobra.Command {
    26  	var opts PullOptions
    27  
    28  	cmd := &cobra.Command{
    29  		Use:   "pull [OPTIONS] NAME[:TAG|@DIGEST]",
    30  		Short: "Pull an image or a repository from a registry",
    31  		Args:  cli.ExactArgs(1),
    32  		RunE: func(cmd *cobra.Command, args []string) error {
    33  			opts.remote = args[0]
    34  			return RunPull(dockerCli, opts)
    35  		},
    36  	}
    37  
    38  	flags := cmd.Flags()
    39  
    40  	flags.BoolVarP(&opts.all, "all-tags", "a", false, "Download all tagged images in the repository")
    41  
    42  	command.AddPlatformFlag(flags, &opts.platform)
    43  	command.AddTrustVerificationFlags(flags, &opts.untrusted, dockerCli.ContentTrustEnabled())
    44  
    45  	return cmd
    46  }
    47  
    48  // RunPull performs a pull against the engine based on the specified options
    49  func RunPull(cli command.Cli, opts PullOptions) error {
    50  	distributionRef, err := reference.ParseNormalizedNamed(opts.remote)
    51  	switch {
    52  	case err != nil:
    53  		return err
    54  	case opts.all && !reference.IsNameOnly(distributionRef):
    55  		return errors.New("tag can't be used with --all-tags/-a")
    56  	case !opts.all && reference.IsNameOnly(distributionRef):
    57  		distributionRef = reference.TagNameOnly(distributionRef)
    58  		if tagged, ok := distributionRef.(reference.Tagged); ok {
    59  			fmt.Fprintf(cli.Out(), "Using default tag: %s\n", tagged.Tag())
    60  		}
    61  	}
    62  
    63  	ctx := context.Background()
    64  	imgRefAndAuth, err := trust.GetImageReferencesAndAuth(ctx, nil, AuthResolver(cli), distributionRef.String())
    65  	if err != nil {
    66  		return err
    67  	}
    68  
    69  	// Check if reference has a digest
    70  	_, isCanonical := distributionRef.(reference.Canonical)
    71  	if !opts.untrusted && !isCanonical {
    72  		err = trustedPull(ctx, cli, imgRefAndAuth, opts.platform)
    73  	} else {
    74  		err = imagePullPrivileged(ctx, cli, imgRefAndAuth, opts.all, opts.platform)
    75  	}
    76  	if err != nil {
    77  		if strings.Contains(err.Error(), "when fetching 'plugin'") {
    78  			return errors.New(err.Error() + " - Use `docker plugin install`")
    79  		}
    80  		return err
    81  	}
    82  	return nil
    83  }