// WaitForEnviron waits for an valid environment to arrive from the given
// watcher. It terminates with ErrWaitAborted if it receives a value on abort.
//
// In practice, it shouldn't wait at all: juju *should* never deliver invalid
// environ configs. Regardless, it should be considered deprecated; clients
// should prefer to access an Environ via a shared Tracker.
//
// It never takes responsibility for the supplied watcher; the client remains
// responsible for detecting and handling any watcher errors that may occur,
// whether this func succeeds or fails.
func WaitForEnviron(
// TODO(wallyworld) - pass in credential watcher
w watcher.NotifyWatcher,
getter environs.EnvironConfigGetter,
newEnviron environs.NewEnvironFunc,
abort <-chan struct{},
) (environs.Environ, error) {
for {
select {
case <-abort:
return nil, ErrWaitAborted
case _, ok := <-w.Changes():
if !ok {
return nil, errors.New("environ config watch closed")
}
// First check the model config is valid as we want to exit with
// an error if we have received a config but it is not valid.
// This distinguishes from the case where environ construction fails
// because no config has been received yet.
if _, err := getter.ModelConfig(); err != nil {
return nil, errors.Annotate(err, "cannot read environ config")
}
environ, err := environs.GetEnviron(getter, newEnviron)
if err == nil {
return environ, nil
}
logger.Errorf("loaded invalid environment configuration: %v", err)
}
}
}
// NetworkingEnvironFromModelConfig constructs and returns
// environs.NetworkingEnviron using the given configGetter. Returns an error
// satisfying errors.IsNotSupported() if the model config does not support
// networking features.
func NetworkingEnvironFromModelConfig(configGetter environs.EnvironConfigGetter) (environs.NetworkingEnviron, error) {
modelConfig, err := configGetter.ModelConfig()
if err != nil {
return nil, errors.Annotate(err, "failed to get model config")
}
if modelConfig.Type() == "dummy" {
return nil, errors.NotSupportedf("dummy provider network config")
}
env, err := environs.GetEnviron(configGetter, environs.New)
if err != nil {
return nil, errors.Annotate(err, "failed to construct a model from config")
}
netEnviron, supported := environs.SupportsNetworking(env)
if !supported {
// " not supported" will be appended to the message below.
return nil, errors.NotSupportedf("model %q networking", modelConfig.Name())
}
return netEnviron, nil
}