github.com/makyo/juju@v0.0.0-20160425123129-2608902037e9/state/gui.go (about)

     1  // Copyright 2016 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package state
     5  
     6  import (
     7  	"github.com/juju/errors"
     8  	"github.com/juju/version"
     9  	"gopkg.in/mgo.v2"
    10  	"gopkg.in/mgo.v2/bson"
    11  )
    12  
    13  // guiSettingsDoc represents the Juju GUI settings in MongoDB.
    14  type guiSettingsDoc struct {
    15  	// CurrentVersion is the version of the Juju GUI currently served by
    16  	// the controller when requesting the GUI via HTTP.
    17  	CurrentVersion version.Number `bson:"current-version"`
    18  }
    19  
    20  // GUISetVersion sets the Juju GUI version that the controller must serve.
    21  func (st *State) GUISetVersion(vers version.Number) error {
    22  	// Check that the provided version is actually present in the GUI storage.
    23  	storage, err := st.GUIStorage()
    24  	if err != nil {
    25  		return errors.Annotate(err, "cannot open GUI storage")
    26  	}
    27  	defer storage.Close()
    28  	if _, err = storage.Metadata(vers.String()); err != nil {
    29  		return errors.Annotatef(err, "cannot find %q GUI version in the storage", vers)
    30  	}
    31  
    32  	// Set the current version.
    33  	settings, closer := st.getCollection(guisettingsC)
    34  	defer closer()
    35  	if _, err = settings.Writeable().Upsert(nil, bson.D{{"current-version", vers}}); err != nil {
    36  		return errors.Annotate(err, "cannot set current GUI version")
    37  	}
    38  	return nil
    39  }
    40  
    41  // GUIVersion returns the Juju GUI version currently served by the controller.
    42  func (st *State) GUIVersion() (vers version.Number, err error) {
    43  	settings, closer := st.getCollection(guisettingsC)
    44  	defer closer()
    45  
    46  	// Retrieve the settings document.
    47  	var doc guiSettingsDoc
    48  	err = settings.Find(nil).Select(bson.D{{"current-version", 1}}).One(&doc)
    49  	if err == nil {
    50  		return doc.CurrentVersion, nil
    51  	}
    52  	if err == mgo.ErrNotFound {
    53  		return vers, errors.NotFoundf("Juju GUI version")
    54  	}
    55  	return vers, errors.Trace(err)
    56  }