DockerCLI/cli-plugins/manager/plugin.go

111 lines
3.1 KiB
Go

package manager
import (
"encoding/json"
"path/filepath"
"regexp"
"runtime"
"strings"
"github.com/pkg/errors"
"github.com/spf13/cobra"
)
var (
pluginNameRe = regexp.MustCompile("^[a-z][a-z0-9]*$")
)
// Plugin represents a potential plugin with all it's metadata.
type Plugin struct {
Metadata
Name string
Path string
// Err is non-nil if the plugin failed one of the candidate tests.
Err error `json:",omitempty"`
// ShadowedPaths contains the paths of any other plugins which this plugin takes precedence over.
ShadowedPaths []string `json:",omitempty"`
}
// newPlugin determines if the given candidate is valid and returns a
// Plugin. If the candidate fails one of the tests then `Plugin.Err`
// is set, but the `Plugin` is still returned with no error. An error
// is only returned due to a non-recoverable error.
func newPlugin(c Candidate, rootcmd *cobra.Command) (Plugin, error) {
path := c.Path()
if path == "" {
return Plugin{}, errors.New("plugin candidate path cannot be empty")
}
// The candidate listing process should have skipped anything
// which would fail here, so there are all real errors.
fullname := filepath.Base(path)
if fullname == "." {
return Plugin{}, errors.Errorf("unable to determine basename of plugin candidate %q", path)
}
if runtime.GOOS == "windows" {
exe := ".exe"
if !strings.HasSuffix(fullname, exe) {
return Plugin{}, errors.Errorf("plugin candidate %q lacks required %q suffix", path, exe)
}
fullname = strings.TrimSuffix(fullname, exe)
}
if !strings.HasPrefix(fullname, NamePrefix) {
return Plugin{}, errors.Errorf("plugin candidate %q does not have %q prefix", path, NamePrefix)
}
p := Plugin{
Name: strings.TrimPrefix(fullname, NamePrefix),
Path: path,
}
// Now apply the candidate tests, so these update p.Err.
if !pluginNameRe.MatchString(p.Name) {
p.Err = errors.Errorf("plugin candidate %q did not match %q", p.Name, pluginNameRe.String())
return p, nil
}
if rootcmd != nil {
for _, cmd := range rootcmd.Commands() {
// Ignore conflicts with commands which are
// just plugin stubs (i.e. from a previous
// call to AddPluginCommandStubs).
if p := cmd.Annotations[CommandAnnotationPlugin]; p == "true" {
continue
}
if cmd.Name() == p.Name {
p.Err = errors.Errorf("plugin %q duplicates builtin command", p.Name)
return p, nil
}
if cmd.HasAlias(p.Name) {
p.Err = errors.Errorf("plugin %q duplicates an alias of builtin command %q", p.Name, cmd.Name())
return p, nil
}
}
}
// We are supposed to check for relevant execute permissions here. Instead we rely on an attempt to execute.
meta, err := c.Metadata()
if err != nil {
p.Err = errors.Wrap(err, "failed to fetch metadata")
return p, nil
}
if err := json.Unmarshal(meta, &p.Metadata); err != nil {
p.Err = errors.Wrap(err, "invalid metadata")
return p, nil
}
if p.Metadata.SchemaVersion != "0.1.0" {
p.Err = errors.Errorf("plugin SchemaVersion %q is not valid, must be 0.1.0", p.Metadata.SchemaVersion)
return p, nil
}
if p.Metadata.Vendor == "" {
p.Err = errors.Errorf("plugin metadata does not define a vendor")
return p, nil
}
return p, nil
}