pkg/plugins/discovery.go
David Calavera 7312c4b8bb Plugins JSON spec.
Allow full configuration of external plugins via a JSON document.

Signed-off-by: David Calavera <david.calavera@gmail.com>
2015-06-29 10:32:18 -07:00

105 lines
2 KiB
Go

package plugins
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"net/url"
"os"
"path/filepath"
"strings"
)
const defaultLocalRegistry = "/usr/share/docker/plugins"
var (
ErrNotFound = errors.New("Plugin not found")
)
type Registry interface {
Plugins() ([]*Plugin, error)
Plugin(name string) (*Plugin, error)
}
type LocalRegistry struct {
path string
}
func newLocalRegistry(path string) *LocalRegistry {
if len(path) == 0 {
path = defaultLocalRegistry
}
return &LocalRegistry{path}
}
func (l *LocalRegistry) Plugin(name string) (*Plugin, error) {
filepath := filepath.Join(l.path, name)
specpath := filepath + ".spec"
if fi, err := os.Stat(specpath); err == nil {
return readPluginSpecInfo(specpath, fi)
}
socketpath := filepath + ".sock"
if fi, err := os.Stat(socketpath); err == nil {
return readPluginSocketInfo(socketpath, fi)
}
jsonpath := filepath + ".json"
if _, err := os.Stat(jsonpath); err == nil {
return readPluginJSONInfo(name, jsonpath)
}
return nil, ErrNotFound
}
func readPluginSpecInfo(path string, fi os.FileInfo) (*Plugin, error) {
name := strings.Split(fi.Name(), ".")[0]
content, err := ioutil.ReadFile(path)
if err != nil {
return nil, err
}
addr := strings.TrimSpace(string(content))
u, err := url.Parse(addr)
if err != nil {
return nil, err
}
if len(u.Scheme) == 0 {
return nil, fmt.Errorf("Unknown protocol")
}
return newLocalPlugin(name, addr), nil
}
func readPluginSocketInfo(path string, fi os.FileInfo) (*Plugin, error) {
name := strings.Split(fi.Name(), ".")[0]
if fi.Mode()&os.ModeSocket == 0 {
return nil, fmt.Errorf("%s is not a socket", path)
}
return newLocalPlugin(name, "unix://"+path), nil
}
func readPluginJSONInfo(name, path string) (*Plugin, error) {
f, err := os.Open(path)
if err != nil {
return nil, err
}
defer f.Close()
var p Plugin
if err := json.NewDecoder(f).Decode(&p); err != nil {
return nil, err
}
p.Name = name
if len(p.TLSConfig.CAFile) == 0 {
p.TLSConfig.InsecureSkipVerify = true
}
return &p, nil
}