// addCharm interprets the new charmRef and adds the specified charm if the new charm is different // to what's already deployed as specified by oldURL. func (c *upgradeCharmCommand) addCharm( oldURL *charm.URL, charmRef string, client *api.Client, resolver *charmURLResolver, ) (charmstore.CharmID, *macaroon.Macaroon, error) { var id charmstore.CharmID // Charm may have been supplied via a path reference. ch, newURL, err := charmrepo.NewCharmAtPathForceSeries(charmRef, oldURL.Series, c.ForceSeries) if err == nil { _, newName := filepath.Split(charmRef) if newName != oldURL.Name { return id, nil, fmt.Errorf("cannot upgrade %q to %q", oldURL.Name, newName) } addedURL, err := client.AddLocalCharm(newURL, ch) id.URL = addedURL return id, nil, err } if _, ok := err.(*charmrepo.NotFoundError); ok { return id, nil, errors.Errorf("no charm found at %q", charmRef) } // If we get a "not exists" or invalid path error then we attempt to interpret // the supplied charm reference as a URL below, otherwise we return the error. if err != os.ErrNotExist && !charmrepo.IsInvalidPathError(err) { return id, nil, err } // Charm has been supplied as a URL so we resolve and deploy using the store. newURL, channel, supportedSeries, repo, err := resolver.resolve(charmRef) if err != nil { return id, nil, errors.Trace(err) } id.Channel = channel if !c.ForceSeries && oldURL.Series != "" && newURL.Series == "" && !isSeriesSupported(oldURL.Series, supportedSeries) { series := []string{"no series"} if len(supportedSeries) > 0 { series = supportedSeries } return id, nil, errors.Errorf( "cannot upgrade from single series %q charm to a charm supporting %q. Use --force-series to override.", oldURL.Series, series, ) } // If no explicit revision was set with either SwitchURL // or Revision flags, discover the latest. if *newURL == *oldURL { newRef, _ := charm.ParseURL(charmRef) if newRef.Revision != -1 { return id, nil, fmt.Errorf("already running specified charm %q", newURL) } if newURL.Schema == "cs" { // No point in trying to upgrade a charm store charm when // we just determined that's the latest revision // available. return id, nil, fmt.Errorf("already running latest charm %q", newURL) } } curl, csMac, err := addCharmFromURL(client, newURL, channel, repo) if err != nil { return id, nil, errors.Trace(err) } id.URL = curl return id, csMac, nil }