// Stage causes subsequent calls to Deploy to deploy the supplied charm. func (d *Deployer) Stage(bun *charm.Bundle, url *charm.URL) error { // Read present state of current. if err := os.MkdirAll(d.path, 0755); err != nil { return err } defer d.collectOrphans() srcExists, err := d.current.Exists() if err != nil { return err } if srcExists { prevURL, err := ReadCharmURL(d.current) if err != nil { return err } if *url == *prevURL { return nil } } // Prepare a fresh repository for the update, using current's history // if it exists. path, err := d.newDir("update") if err != nil { return err } var repo *GitDir if srcExists { repo, err = d.current.Clone(path) } else { repo = NewGitDir(path) err = repo.Init() } if err != nil { return err } // Write the desired new state and commit. if err = bun.ExpandTo(path); err != nil { return err } if err = WriteCharmURL(repo, url); err != nil { return err } if err = repo.Snapshotf("Imported charm %q from %q.", url, bun.Path); err != nil { return err } // Atomically rename fresh repository to current. tmplink := filepath.Join(path, "tmplink") if err = os.Symlink(path, tmplink); err != nil { return err } return os.Rename(tmplink, d.current.Path()) }