func NewConfigFromContents()

in xds/client/bootstrap/bootstrap.go [316:432]
98 lines of code
29 McCabe index (conditional complexity)

func NewConfigFromContents(data []byte) (*Config, error) {
	config := &Config{}

	var jsonData map[string]json.RawMessage
	if err := json.Unmarshal(data, &jsonData); err != nil {
		return nil, fmt.Errorf("xds: Failed to parse bootstrap config: %v", err)
	}

	var node *v3corepb.Node
	m := jsonpb.Unmarshaler{AllowUnknownFields: true}
	for k, v := range jsonData {
		switch k {
		case "node":
			// We unconditionally convert the JSON into a v3.Node proto. The v3
			// proto does not contain the deprecated field "build_version" from
			// the v2 proto. We do not expect the bootstrap file to contain the
			// "build_version" field. In any case, the unmarshal will succeed
			// because we have set the `AllowUnknownFields` option on the
			// unmarshaler.
			node = &v3corepb.Node{}
			if err := m.Unmarshal(bytes.NewReader(v), node); err != nil {
				return nil, fmt.Errorf("xds: jsonpb.Unmarshal(%v) for field %q failed during bootstrap: %v", string(v), k, err)
			}
		case "xds_servers":
			if err := json.Unmarshal(v, &config.XDSServer); err != nil {
				return nil, fmt.Errorf("xds: json.Unmarshal(%v) for field %q failed during bootstrap: %v", string(v), k, err)
			}
		case "certificate_providers":
			var providerInstances map[string]json.RawMessage
			if err := json.Unmarshal(v, &providerInstances); err != nil {
				return nil, fmt.Errorf("xds: json.Unmarshal(%v) for field %q failed during bootstrap: %v", string(v), k, err)
			}
			configs := make(map[string]*certprovider.BuildableConfig)
			getBuilder := internal.GetCertificateProviderBuilder.(func(string) certprovider.Builder)
			for instance, data := range providerInstances {
				var nameAndConfig struct {
					PluginName string          `json:"plugin_name"`
					Config     json.RawMessage `json:"config"`
				}
				if err := json.Unmarshal(data, &nameAndConfig); err != nil {
					return nil, fmt.Errorf("xds: json.Unmarshal(%v) for field %q failed during bootstrap: %v", string(v), instance, err)
				}

				name := nameAndConfig.PluginName
				parser := getBuilder(nameAndConfig.PluginName)
				if parser == nil {
					// We ignore plugins that we do not know about.
					continue
				}
				bc, err := parser.ParseConfig(nameAndConfig.Config)
				if err != nil {
					return nil, fmt.Errorf("xds: Config parsing for plugin %q failed: %v", name, err)
				}
				configs[instance] = bc
			}
			config.CertProviderConfigs = configs
		case "server_listener_resource_name_template":
			if err := json.Unmarshal(v, &config.ServerListenerResourceNameTemplate); err != nil {
				return nil, fmt.Errorf("xds: json.Unmarshal(%v) for field %q failed during bootstrap: %v", string(v), k, err)
			}
		case "client_default_listener_resource_name_template":
			if !envconfig.XDSFederation {
				dubbogoLogger.Warnf("xds: bootstrap field %v is not support when Federation is disabled", k)
				continue
			}
			if err := json.Unmarshal(v, &config.ClientDefaultListenerResourceNameTemplate); err != nil {
				return nil, fmt.Errorf("xds: json.Unmarshal(%v) for field %q failed during bootstrap: %v", string(v), k, err)
			}
		case "authorities":
			if !envconfig.XDSFederation {
				dubbogoLogger.Warnf("xds: bootstrap field %v is not support when Federation is disabled", k)
				continue
			}
			if err := json.Unmarshal(v, &config.Authorities); err != nil {
				return nil, fmt.Errorf("xds: json.Unmarshal(%v) for field %q failed during bootstrap: %v", string(v), k, err)
			}
		default:
			dubbogoLogger.Warnf("Bootstrap content has unknown field: %s", k)
		}
		// Do not fail the xDS bootstrap when an unknown field is seen. This can
		// happen when an older version client reads a newer version bootstrap
		// file with new fields.
	}

	if config.ClientDefaultListenerResourceNameTemplate == "" {
		// Default value of the default client listener name template is "%s".
		config.ClientDefaultListenerResourceNameTemplate = "%s"
	}
	if config.XDSServer == nil {
		return nil, fmt.Errorf("xds: Required field %q not found in bootstrap %s", "xds_servers", jsonData["xds_servers"])
	}
	if config.XDSServer.ServerURI == "" {
		return nil, fmt.Errorf("xds: Required field %q not found in bootstrap %s", "xds_servers.server_uri", jsonData["xds_servers"])
	}
	if config.XDSServer.Creds == nil {
		return nil, fmt.Errorf("xds: Required field %q doesn't contain valid value in bootstrap %s", "xds_servers.channel_creds", jsonData["xds_servers"])
	}
	// Post-process the authorities' client listener resource template field:
	// - if set, it must start with "xdstp://<authority_name>/"
	// - if not set, it defaults to "xdstp://<authority_name>/envoy.config.listener.v3.Listener/%s"
	for name, authority := range config.Authorities {
		prefix := fmt.Sprintf("xdstp://%s", name)
		if authority.ClientListenerResourceNameTemplate == "" {
			authority.ClientListenerResourceNameTemplate = prefix + "/envoy.config.listener.v3.Listener/%s"
			continue
		}
		if !strings.HasPrefix(authority.ClientListenerResourceNameTemplate, prefix) {
			return nil, fmt.Errorf("xds: field ClientListenerResourceNameTemplate %q of authority %q doesn't start with prefix %q", authority.ClientListenerResourceNameTemplate, name, prefix)
		}
	}

	if err := config.updateNodeProto(node); err != nil {
		return nil, err
	}
	dubbogoLogger.Infof("Bootstrap config for creating xds-client: %v", pretty.ToJSON(config))
	return config, nil
}