github.com/kaisenlinux/docker@v0.0.0-20230510090727-ea55db55fac7/cli/cli-plugins/manager/plugin.go (about)

     1  package manager
     2  
     3  import (
     4  	"encoding/json"
     5  	"path/filepath"
     6  	"regexp"
     7  	"strings"
     8  
     9  	"github.com/pkg/errors"
    10  	"github.com/spf13/cobra"
    11  )
    12  
    13  var (
    14  	pluginNameRe = regexp.MustCompile("^[a-z][a-z0-9]*$")
    15  )
    16  
    17  // Plugin represents a potential plugin with all it's metadata.
    18  type Plugin struct {
    19  	Metadata
    20  
    21  	Name string `json:",omitempty"`
    22  	Path string `json:",omitempty"`
    23  
    24  	// Err is non-nil if the plugin failed one of the candidate tests.
    25  	Err error `json:",omitempty"`
    26  
    27  	// ShadowedPaths contains the paths of any other plugins which this plugin takes precedence over.
    28  	ShadowedPaths []string `json:",omitempty"`
    29  }
    30  
    31  // newPlugin determines if the given candidate is valid and returns a
    32  // Plugin.  If the candidate fails one of the tests then `Plugin.Err`
    33  // is set, and is always a `pluginError`, but the `Plugin` is still
    34  // returned with no error. An error is only returned due to a
    35  // non-recoverable error.
    36  func newPlugin(c Candidate, rootcmd *cobra.Command) (Plugin, error) {
    37  	path := c.Path()
    38  	if path == "" {
    39  		return Plugin{}, errors.New("plugin candidate path cannot be empty")
    40  	}
    41  
    42  	// The candidate listing process should have skipped anything
    43  	// which would fail here, so there are all real errors.
    44  	fullname := filepath.Base(path)
    45  	if fullname == "." {
    46  		return Plugin{}, errors.Errorf("unable to determine basename of plugin candidate %q", path)
    47  	}
    48  	var err error
    49  	if fullname, err = trimExeSuffix(fullname); err != nil {
    50  		return Plugin{}, errors.Wrapf(err, "plugin candidate %q", path)
    51  	}
    52  	if !strings.HasPrefix(fullname, NamePrefix) {
    53  		return Plugin{}, errors.Errorf("plugin candidate %q: does not have %q prefix", path, NamePrefix)
    54  	}
    55  
    56  	p := Plugin{
    57  		Name: strings.TrimPrefix(fullname, NamePrefix),
    58  		Path: path,
    59  	}
    60  
    61  	// Now apply the candidate tests, so these update p.Err.
    62  	if !pluginNameRe.MatchString(p.Name) {
    63  		p.Err = NewPluginError("plugin candidate %q did not match %q", p.Name, pluginNameRe.String())
    64  		return p, nil
    65  	}
    66  
    67  	if rootcmd != nil {
    68  		for _, cmd := range rootcmd.Commands() {
    69  			// Ignore conflicts with commands which are
    70  			// just plugin stubs (i.e. from a previous
    71  			// call to AddPluginCommandStubs).
    72  			if p := cmd.Annotations[CommandAnnotationPlugin]; p == "true" {
    73  				continue
    74  			}
    75  			if cmd.Name() == p.Name {
    76  				p.Err = NewPluginError("plugin %q duplicates builtin command", p.Name)
    77  				return p, nil
    78  			}
    79  			if cmd.HasAlias(p.Name) {
    80  				p.Err = NewPluginError("plugin %q duplicates an alias of builtin command %q", p.Name, cmd.Name())
    81  				return p, nil
    82  			}
    83  		}
    84  	}
    85  
    86  	// We are supposed to check for relevant execute permissions here. Instead we rely on an attempt to execute.
    87  	meta, err := c.Metadata()
    88  	if err != nil {
    89  		p.Err = wrapAsPluginError(err, "failed to fetch metadata")
    90  		return p, nil
    91  	}
    92  
    93  	if err := json.Unmarshal(meta, &p.Metadata); err != nil {
    94  		p.Err = wrapAsPluginError(err, "invalid metadata")
    95  		return p, nil
    96  	}
    97  	if p.Metadata.SchemaVersion != "0.1.0" {
    98  		p.Err = NewPluginError("plugin SchemaVersion %q is not valid, must be 0.1.0", p.Metadata.SchemaVersion)
    99  		return p, nil
   100  	}
   101  	if p.Metadata.Vendor == "" {
   102  		p.Err = NewPluginError("plugin metadata does not define a vendor")
   103  		return p, nil
   104  	}
   105  	return p, nil
   106  }