func getTemplateResources(config Config) ([]*TemplateResource, error) {
	var lastError error
	templates := make([]*TemplateResource, 0)
	log.Debug("Loading template resources from confdir " + config.ConfDir)
	if !isFileExist(config.ConfDir) {
		log.Warning(fmt.Sprintf("Cannot load template resources: confdir '%s' does not exist", config.ConfDir))
		return nil, nil
	}
	paths, err := recursiveFindFiles(config.ConfigDir, "*toml")
	if err != nil {
		return nil, err
	}

	if len(paths) < 1 {
		log.Warning("Found no templates")
	}

	for _, p := range paths {
		log.Debug(fmt.Sprintf("Found template: %s", p))
		t, err := NewTemplateResource(p, config)
		if err != nil {
			lastError = err
			continue
		}
		templates = append(templates, t)
	}
	return templates, lastError
}

// GetValues retrieves the values for the given keys from DynamoDB
func (c *Client) GetValues(keys []string) (map[string]string, error) {
	vars := make(map[string]string)
	for _, key := range keys {
		// Check if we can find the single item
		m := make(map[string]*dynamodb.AttributeValue)
		m["key"] = &dynamodb.AttributeValue{S: aws.String(key)}
		g, err := c.client.GetItem(&dynamodb.GetItemInput{Key: m, TableName: &c.table})
		if err != nil {
			return vars, err
		}

		if g.Item != nil {
			if val, ok := g.Item["value"]; ok {
				if val.S != nil {
					vars[key] = *val.S
				} else {
					log.Warning("Skipping key '%s'. 'value' is not of type 'string'.", key)
				}
				continue
			}
		}

		// Check for nested keys
		q, err := c.client.Scan(
			&dynamodb.ScanInput{
				ScanFilter: map[string]*dynamodb.Condition{
					"key": &dynamodb.Condition{
						AttributeValueList: []*dynamodb.AttributeValue{
							&dynamodb.AttributeValue{S: aws.String(key)}},
						ComparisonOperator: aws.String("BEGINS_WITH")}},
				AttributesToGet: []*string{aws.String("key"), aws.String("value")},
				TableName:       aws.String(c.table),
				Select:          aws.String("SPECIFIC_ATTRIBUTES"),
			})

		if err != nil {
			return vars, err
		}

		for _, i := range q.Items {
			item := i
			if val, ok := item["value"]; ok {
				if val.S != nil {
					vars[*item["key"].S] = *val.S
				} else {
					log.Warning("Skipping key '%s'. 'value' is not of type 'string'.", *item["key"].S)
				}
				continue
			}
		}
	}
	return vars, nil
}

// ProcessTemplateResources is a convenience function that loads all the
// template resources and processes them serially. Called from main.
// It returns a list of errors if any.
func ProcessTemplateResources(c etcdutil.EtcdClient) []error {
	runErrors := make([]error, 0)
	var err error
	if c == nil {
		runErrors = append(runErrors, errors.New("An etcd client is required"))
		return runErrors
	}
	log.Debug("Loading template resources from confdir " + config.ConfDir())
	if !isFileExist(config.ConfDir()) {
		log.Warning(fmt.Sprintf("Cannot load template resources confdir '%s' does not exist", config.ConfDir()))
		return runErrors
	}
	paths, err := filepath.Glob(filepath.Join(config.ConfigDir(), "*toml"))
	if err != nil {
		runErrors = append(runErrors, err)
		return runErrors
	}
	for _, p := range paths {
		log.Debug("Processing template resource " + p)
		t, err := NewTemplateResourceFromPath(p, c)
		if err != nil {
			runErrors = append(runErrors, err)
			log.Error(err.Error())
			continue
		}
		if err := t.process(); err != nil {
			runErrors = append(runErrors, err)
			log.Error(err.Error())
			continue
		}
		log.Debug("Processing of template resource " + p + " complete")
	}
	return runErrors
}

// sync compares the staged and dest config files and attempts to sync them
// if they differ. sync will run a config check command if set before
// overwriting the target config file. Finally, sync will run a reload command
// if set to have the application or service pick up the changes.
// It returns an error if any.
func (t *TemplateResource) sync() error {
	staged := t.StageFile.Name()
	defer os.Remove(staged)
	log.Debug("Comparing candidate config to " + t.Dest)
	ok, err := sameConfig(staged, t.Dest)
	if err != nil {
		log.Error(err.Error())
	}
	if config.Noop() {
		log.Warning("Noop mode enabled " + t.Dest + " will not be modified")
		return nil
	}
	if !ok {
		log.Info("Target config " + t.Dest + " out of sync")
		if t.CheckCmd != "" {
			if err := t.check(); err != nil {
				return errors.New("Config check failed: " + err.Error())
			}
		}
		log.Debug("Overwriting target config " + t.Dest)
		if err := os.Rename(staged, t.Dest); err != nil {
			return err
		}
		if t.ReloadCmd != "" {
			if err := t.reload(); err != nil {
				return err
			}
		}
		log.Info("Target config " + t.Dest + " has been updated")
	} else {
		log.Info("Target config " + t.Dest + " in sync")
	}
	return nil
}

// LoadConfig initializes the confd configuration by first setting defaults,
// then overriding setting from the confd config file, and finally overriding
// settings from flags set on the command line.
// It returns an error if any.
func LoadConfig(path string) error {
	setDefaults()
	if path == "" {
		log.Warning("Skipping confd config file.")
	} else {
		log.Debug("Loading " + path)

		configBytes, err := ioutil.ReadFile(path)
		if err != nil {
			return err
		}

		_, err = toml.Decode(string(configBytes), &config)
		if err != nil {
			return err
		}
	}
	processFlags()
	if !isValidateEtcdScheme(config.Confd.EtcdScheme) {
		return errors.New("Invalid etcd scheme: " + config.Confd.EtcdScheme)
	}
	err := setEtcdHosts()
	if err != nil {
		return err
	}
	return nil
}

// sync compares the staged and dest config files and attempts to sync them
// if they differ. sync will run a config check command if set before
// overwriting the target config file. Finally, sync will run a reload command
// if set to have the application or service pick up the changes.
// It returns an error if any.
func (t *TemplateResource) sync() error {
	staged := t.StageFile.Name()
	if t.keepStageFile {
		log.Info("Keeping staged file: " + staged)
	} else {
		defer os.Remove(staged)
	}

	log.Debug("Comparing candidate config to " + t.Dest)
	ok, err := sameConfig(staged, t.Dest)
	if err != nil {
		log.Error(err.Error())
	}
	if t.noop {
		log.Warning("Noop mode enabled. " + t.Dest + " will not be modified")
		return nil
	}
	if !ok {
		log.Info("Target config " + t.Dest + " out of sync")
		if t.CheckCmd != "" {
			if err := t.check(); err != nil {
				return errors.New("Config check failed: " + err.Error())
			}
		}
		log.Debug("Overwriting target config " + t.Dest)
		err := os.Rename(staged, t.Dest)
		if err != nil {
			if strings.Contains(err.Error(), "device or resource busy") {
				log.Debug("Rename failed - target is likely a mount. Trying to write instead")
				// try to open the file and write to it
				var contents []byte
				var rerr error
				contents, rerr = ioutil.ReadFile(staged)
				if rerr != nil {
					return rerr
				}
				err := ioutil.WriteFile(t.Dest, contents, t.FileMode)
				// make sure owner and group match the temp file, in case the file was created with WriteFile
				os.Chown(t.Dest, t.Uid, t.Gid)
				if err != nil {
					return err
				}
			} else {
				return err
			}
		}
		if t.ReloadCmd != "" {
			if err := t.reload(); err != nil {
				return err
			}
		}
		log.Info("Target config " + t.Dest + " has been updated")
	} else {
		log.Debug("Target config " + t.Dest + " in sync")
	}
	return nil
}

// recursively walks on all the values of a specific key and set them in the variables map
func flatten(key string, value interface{}, vars map[string]string) {
	switch value.(type) {
	case string:
		log.Debug("setting key %s to: %s", key, value)
		vars[key] = value.(string)
	case map[string]interface{}:
		inner := value.(map[string]interface{})
		for innerKey, innerValue := range inner {
			innerKey = path.Join(key, "/", innerKey)
			flatten(innerKey, innerValue, vars)
		}
	default: // we don't know how to handle non string or maps of strings
		log.Warning("type of '%s' is not supported (%T)", key, value)
	}
}

func getTemplateResources(config Config) ([]*TemplateResource, error) {
	var lastError error
	templates := make([]*TemplateResource, 0)
	log.Debug("Loading template resources from confdir " + config.ConfDir)
	if !isFileExist(config.ConfDir) {
		log.Warning(fmt.Sprintf("Cannot load template resources: confdir '%s' does not exist", config.ConfDir))
		return nil, nil
	}
	paths, err := recursiveFindFiles(config.ConfigDir, "*toml")
	if err != nil {
		return nil, err
	}
	for _, p := range paths {
		t, err := NewTemplateResource(p, config)
		if err != nil {
			lastError = err
			continue
		}
		templates = append(templates, t)
	}

	// get dynamic TemplateResources
	log.Info("parse dynamic keys")
	result, err := config.StoreClient.GetValues([]string{"_confd"})
	if err == nil {
		for k, v := range result {
			log.Info("dynamic key: " + k + " / " + v)
			t, err := NewTemplateResource(config.ConfigDir+"/"+v, config)
			if err != nil {
				lastError = err
				continue
			}

			split := strings.Split(k, "/")
			key := "/" + split[len(split)-1]
			t.Dest = strings.Replace(t.Dest, "{{.token}}", key, 1)
			t.ReloadCmd = strings.Replace(t.ReloadCmd, "{{.token}}", key, 1)
			t.Prefix = key
			t.prefix = key
			templates = append(templates, t)
		}
	}

	return templates, lastError
}

func getTemplateResources(config Config) ([]*TemplateResource, error) {
	var lastError error
	templates := make([]*TemplateResource, 0)
	log.Debug("Loading template resources from confdir " + config.ConfDir)
	if !isFileExist(config.ConfDir) {
		log.Warning(fmt.Sprintf("Cannot load template resources: confdir '%s' does not exist", config.ConfDir))
		return nil, nil
	}
	paths, err := filepath.Glob(filepath.Join(config.ConfigDir, "*toml"))
	if err != nil {
		return nil, err
	}
	for _, p := range paths {
		t, err := NewTemplateResource(p, config)
		if err != nil {
			lastError = err
			continue
		}
		templates = append(templates, t)
	}
	return templates, lastError
}

// initConfig initializes the confd configuration by first setting defaults,
// then overriding setting from the confd config file, and finally overriding
// settings from flags set on the command line.
// It returns an error if any.
func initConfig() error {
	if configFile == "" {
		if _, err := os.Stat(defaultConfigFile); !os.IsNotExist(err) {
			configFile = defaultConfigFile
		}
	}
	// Set defaults.
	config = Config{
		Backend:  "etcd",
		ConfDir:  "/etc/confd",
		Interval: 600,
		Prefix:   "/",
		Scheme:   "http",
	}
	// Update config from the TOML configuration file.
	if configFile == "" {
		log.Warning("Skipping confd config file.")
	} else {
		log.Debug("Loading " + configFile)
		configBytes, err := ioutil.ReadFile(configFile)
		if err != nil {
			return err
		}
		_, err = toml.Decode(string(configBytes), &config)
		if err != nil {
			return err
		}
	}
	// Update config from commandline flags.
	processFlags()

	// Configure logging.
	log.SetQuiet(config.Quiet)
	log.SetVerbose(config.Verbose)
	log.SetDebug(config.Debug)

	// Update BackendNodes from SRV records.
	if config.Backend != "env" && config.SRVDomain != "" {
		log.Info("SRV domain set to " + config.SRVDomain)
		srvNodes, err := getBackendNodesFromSRV(config.Backend, config.SRVDomain, config.Scheme)
		if err != nil {
			return errors.New("Cannot get nodes from SRV records " + err.Error())
		}
		config.BackendNodes = srvNodes
	}
	if len(config.BackendNodes) == 0 {
		switch config.Backend {
		case "consul":
			config.BackendNodes = []string{"127.0.0.1:8500"}
		case "etcd":
			peerstr := os.Getenv("ETCDCTL_PEERS")
			if len(peerstr) > 0 {
				config.BackendNodes = strings.Split(peerstr, ",")
			} else {
				config.BackendNodes = []string{"http://127.0.0.1:4001"}
			}
		case "redis":
			config.BackendNodes = []string{"127.0.0.1:6379"}
		}
	}
	// Initialize the storage client
	log.Notice("Backend set to " + config.Backend)

	if config.Watch {
		unsupportedBackends := map[string]bool{
			"zookeeper": true,
			"redis":     true,
		}

		if unsupportedBackends[config.Backend] {
			log.Notice(fmt.Sprintf("Watch is not supported for backend %s. Exiting...", config.Backend))
			os.Exit(1)
		}
	}

	backendsConfig = backends.Config{
		Backend:      config.Backend,
		ClientCaKeys: config.ClientCaKeys,
		ClientCert:   config.ClientCert,
		ClientKey:    config.ClientKey,
		BackendNodes: config.BackendNodes,
		Scheme:       config.Scheme,
	}
	// Template configuration.
	templateConfig = template.Config{
		ConfDir:       config.ConfDir,
		ConfigDir:     filepath.Join(config.ConfDir, "conf.d"),
		KeepStageFile: keepStageFile,
		Noop:          config.Noop,
		Prefix:        config.Prefix,
		TemplateDir:   filepath.Join(config.ConfDir, "templates"),
	}
	return nil
}