github.com/altoros/juju-vmware@v0.0.0-20150312064031-f19ae857ccca/apiserver/common/environwatcher.go (about)

     1  // Copyright 2013 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package common
     5  
     6  import (
     7  	"github.com/juju/juju/apiserver/params"
     8  	"github.com/juju/juju/environs"
     9  	"github.com/juju/juju/state"
    10  	"github.com/juju/juju/state/watcher"
    11  )
    12  
    13  // EnvironWatcher implements two common methods for use by various
    14  // facades - WatchForEnvironConfigChanges and EnvironConfig.
    15  type EnvironWatcher struct {
    16  	st         state.EnvironAccessor
    17  	resources  *Resources
    18  	authorizer Authorizer
    19  }
    20  
    21  // NewEnvironWatcher returns a new EnvironWatcher. Active watchers
    22  // will be stored in the provided Resources. The two GetAuthFunc
    23  // callbacks will be used on each invocation of the methods to
    24  // determine current permissions.
    25  // Right now, environment tags are not used, so both created AuthFuncs
    26  // are called with "" for tag, which means "the current environment".
    27  func NewEnvironWatcher(st state.EnvironAccessor, resources *Resources, authorizer Authorizer) *EnvironWatcher {
    28  	return &EnvironWatcher{
    29  		st:         st,
    30  		resources:  resources,
    31  		authorizer: authorizer,
    32  	}
    33  }
    34  
    35  // WatchForEnvironConfigChanges returns a NotifyWatcher that observes
    36  // changes to the environment configuration.
    37  // Note that although the NotifyWatchResult contains an Error field,
    38  // it's not used because we are only returning a single watcher,
    39  // so we use the regular error return.
    40  func (e *EnvironWatcher) WatchForEnvironConfigChanges() (params.NotifyWatchResult, error) {
    41  	result := params.NotifyWatchResult{}
    42  	watch := e.st.WatchForEnvironConfigChanges()
    43  	// Consume the initial event. Technically, API
    44  	// calls to Watch 'transmit' the initial event
    45  	// in the Watch response. But NotifyWatchers
    46  	// have no state to transmit.
    47  	if _, ok := <-watch.Changes(); ok {
    48  		result.NotifyWatcherId = e.resources.Register(watch)
    49  	} else {
    50  		return result, watcher.EnsureErr(watch)
    51  	}
    52  	return result, nil
    53  }
    54  
    55  // EnvironConfig returns the current environment's configuration.
    56  func (e *EnvironWatcher) EnvironConfig() (params.EnvironConfigResult, error) {
    57  	result := params.EnvironConfigResult{}
    58  
    59  	config, err := e.st.EnvironConfig()
    60  	if err != nil {
    61  		return result, err
    62  	}
    63  	allAttrs := config.AllAttrs()
    64  
    65  	if !e.authorizer.AuthEnvironManager() {
    66  		// Mask out any secrets in the environment configuration
    67  		// with values of the same type, so it'll pass validation.
    68  		//
    69  		// TODO(dimitern) 201309-26 bug #1231384
    70  		// Delete the code below and mark the bug as fixed,
    71  		// once it's live tested on MAAS and 1.16 compatibility
    72  		// is dropped.
    73  		env, err := environs.New(config)
    74  		if err != nil {
    75  			return result, err
    76  		}
    77  		secretAttrs, err := env.Provider().SecretAttrs(config)
    78  		for k := range secretAttrs {
    79  			allAttrs[k] = "not available"
    80  		}
    81  	}
    82  	result.Config = allAttrs
    83  	return result, nil
    84  }