github.com/jiasir/docker@v1.3.3-0.20170609024000-252e610103e7/pkg/authorization/plugin.go (about)

     1  package authorization
     2  
     3  import (
     4  	"sync"
     5  
     6  	"github.com/docker/docker/pkg/plugingetter"
     7  	"github.com/docker/docker/pkg/plugins"
     8  )
     9  
    10  // Plugin allows third party plugins to authorize requests and responses
    11  // in the context of docker API
    12  type Plugin interface {
    13  	// Name returns the registered plugin name
    14  	Name() string
    15  
    16  	// AuthZRequest authorizes the request from the client to the daemon
    17  	AuthZRequest(*Request) (*Response, error)
    18  
    19  	// AuthZResponse authorizes the response from the daemon to the client
    20  	AuthZResponse(*Request) (*Response, error)
    21  }
    22  
    23  // newPlugins constructs and initializes the authorization plugins based on plugin names
    24  func newPlugins(names []string) []Plugin {
    25  	plugins := []Plugin{}
    26  	pluginsMap := make(map[string]struct{})
    27  	for _, name := range names {
    28  		if _, ok := pluginsMap[name]; ok {
    29  			continue
    30  		}
    31  		pluginsMap[name] = struct{}{}
    32  		plugins = append(plugins, newAuthorizationPlugin(name))
    33  	}
    34  	return plugins
    35  }
    36  
    37  var getter plugingetter.PluginGetter
    38  
    39  // SetPluginGetter sets the plugingetter
    40  func SetPluginGetter(pg plugingetter.PluginGetter) {
    41  	getter = pg
    42  }
    43  
    44  // GetPluginGetter gets the plugingetter
    45  func GetPluginGetter() plugingetter.PluginGetter {
    46  	return getter
    47  }
    48  
    49  // authorizationPlugin is an internal adapter to docker plugin system
    50  type authorizationPlugin struct {
    51  	plugin *plugins.Client
    52  	name   string
    53  	once   sync.Once
    54  }
    55  
    56  func newAuthorizationPlugin(name string) Plugin {
    57  	return &authorizationPlugin{name: name}
    58  }
    59  
    60  func (a *authorizationPlugin) Name() string {
    61  	return a.name
    62  }
    63  
    64  // Set the remote for an authz pluginv2
    65  func (a *authorizationPlugin) SetName(remote string) {
    66  	a.name = remote
    67  }
    68  
    69  func (a *authorizationPlugin) AuthZRequest(authReq *Request) (*Response, error) {
    70  	if err := a.initPlugin(); err != nil {
    71  		return nil, err
    72  	}
    73  
    74  	authRes := &Response{}
    75  	if err := a.plugin.Call(AuthZApiRequest, authReq, authRes); err != nil {
    76  		return nil, err
    77  	}
    78  
    79  	return authRes, nil
    80  }
    81  
    82  func (a *authorizationPlugin) AuthZResponse(authReq *Request) (*Response, error) {
    83  	if err := a.initPlugin(); err != nil {
    84  		return nil, err
    85  	}
    86  
    87  	authRes := &Response{}
    88  	if err := a.plugin.Call(AuthZApiResponse, authReq, authRes); err != nil {
    89  		return nil, err
    90  	}
    91  
    92  	return authRes, nil
    93  }
    94  
    95  // initPlugin initializes the authorization plugin if needed
    96  func (a *authorizationPlugin) initPlugin() error {
    97  	// Lazy loading of plugins
    98  	var err error
    99  	a.once.Do(func() {
   100  		if a.plugin == nil {
   101  			var plugin plugingetter.CompatPlugin
   102  			var e error
   103  
   104  			if pg := GetPluginGetter(); pg != nil {
   105  				plugin, e = pg.Get(a.name, AuthZApiImplements, plugingetter.Lookup)
   106  				a.SetName(plugin.Name())
   107  			} else {
   108  				plugin, e = plugins.Get(a.name, AuthZApiImplements)
   109  			}
   110  			if e != nil {
   111  				err = e
   112  				return
   113  			}
   114  			a.plugin = plugin.Client()
   115  		}
   116  	})
   117  	return err
   118  }