// ReadCharmURL reads the charm identity file from the supplied GitDir.
func ReadCharmURL(d *GitDir) (*charm.URL, error) {
path := filepath.Join(d.path, ".juju-charm")
surl := ""
if err := utils.ReadYaml(path, &surl); err != nil {
return nil, err
}
return charm.ParseURL(surl)
}
// Read reads a State from the file. If the file does not exist it returns
// ErrNoStateFile.
func (f *StateFile) Read() (*State, error) {
var st State
if err := utils.ReadYaml(f.path, &st); err != nil {
if os.IsNotExist(err) {
return nil, ErrNoStateFile
}
}
if err := st.validate(); err != nil {
return nil, fmt.Errorf("cannot read charm state at %q: %v", f.path, err)
}
return &st, nil
}
// ReadStateDir loads a StateDir from the subdirectory of dirPath named
// for the supplied RelationId. If the directory does not exist, no error
// is returned,
func ReadStateDir(dirPath string, relationId int) (d *StateDir, err error) {
d = &StateDir{
filepath.Join(dirPath, strconv.Itoa(relationId)),
State{relationId, map[string]int64{}, ""},
}
defer utils.ErrorContextf(&err, "cannot load relation state from %q", d.path)
if _, err := os.Stat(d.path); os.IsNotExist(err) {
return d, nil
} else if err != nil {
return nil, err
}
fis, err := ioutil.ReadDir(d.path)
if err != nil {
return nil, err
}
for _, fi := range fis {
// Entries with names ending in "-" followed by an integer must be
// files containing valid unit data; all other names are ignored.
name := fi.Name()
i := strings.LastIndex(name, "-")
if i == -1 {
continue
}
svcName := name[:i]
unitId := name[i+1:]
if _, err := strconv.Atoi(unitId); err != nil {
continue
}
unitName := svcName + "/" + unitId
var info diskInfo
if err = utils.ReadYaml(filepath.Join(d.path, name), &info); err != nil {
return nil, fmt.Errorf("invalid unit file %q: %v", name, err)
}
if info.ChangeVersion == nil {
return nil, fmt.Errorf(`invalid unit file %q: "changed-version" not set`, name)
}
d.state.Members[unitName] = *info.ChangeVersion
if info.ChangedPending {
if d.state.ChangedPending != "" {
return nil, fmt.Errorf("%q and %q both have pending changed hooks", d.state.ChangedPending, unitName)
}
d.state.ChangedPending = unitName
}
}
return d, nil
}
// load loads the "machine info" file and parse the content into the info
// object.
func (info *machineInfo) load() error {
return utils.ReadYaml(_MAASInstanceFilename, info)
}