Method loadConfig

runtimeconfig/manager.go:203–280

loadConfig loads all configuration files using the loader function then merges the yaml configuration files into one yaml document. and notifies listeners if successful.

(ctx context.Context)

// loadConfig loads all configuration files using the loader function then merges the yaml configuration files into one yaml document.
// and notifies listeners if successful.
func (om *Manager) loadConfig(ctx context.Context) error {
	rawData := make([][]byte, len(om.providers))
	hashes := map[string]string{}

	for i, p := range om.providers {
		buf, err := p.Read(ctx)
		if err != nil {
			om.configLoadSuccess.Set(0)
			return errors.Wrapf(err, "read %q", p.Name())
		}

		if om.cfg.Preprocessor != nil {
			buf, err = om.cfg.Preprocessor(buf)
			if err != nil {
				om.configLoadSuccess.Set(0)
				return errors.Wrapf(err, "preprocess %q", p.Name())
			}
		}

		rawData[i] = buf
		hashes[p.Name()] = fmt.Sprintf("%x", sha256.Sum256(buf))
	}

	// check if new hashes are the same as before
	sameHashes := true
	for name, h := range hashes {
		if om.fileHashes[name] != h {
			sameHashes = false
			break
		}
	}

	if sameHashes {
		// No need to rebuild runtime config.
		om.configLoadSuccess.Set(1)
		return nil
	}

	mergedConfig := map[string]interface{}{}
	for i, p := range om.providers {
		data := rawData[i]
		yamlFile, err := om.unmarshalMaybeGzipped(p.Name(), data)
		if err != nil {
			om.configLoadSuccess.Set(0)
			return errors.Wrapf(err, "unmarshal %q", p.Name())
		}
		mergedConfig, err = mergeConfigMaps(mergedConfig, yamlFile, "")
		if err != nil {
			om.configLoadSuccess.Set(0)
			return errors.Wrapf(err, "can't merge %q on top of the previous providers", p.Name())
		}
	}

	buf, err := yaml.Marshal(mergedConfig)
	if err != nil {
		om.configLoadSuccess.Set(0)
		return errors.Wrap(err, "marshal file")
	}