config

Documentation

Index

• Constants
• Variables
• type ChangeType
• type ConfigChangedHandler
• type ConfigFile
  • func NewConfigFile(store storage.Storage, file string) *ConfigFile
  • func (cf *ConfigFile) AddChangeHandler(handler ConfigChangedHandler) HandlerID
  • func (cf *ConfigFile) AddPriorityChangeHandler(handler ConfigChangedHandler, priority int) HandlerID
  • func (cf *ConfigFile) Delete() error
  • func (cf *ConfigFile) Exists() (bool, error)
  • func (cf *ConfigFile) Path() string
  • func (cf *ConfigFile) Read() ([]byte, error)
  • func (cf *ConfigFile) Refresh() ([]byte, error)
  • func (cf *ConfigFile) RemoveAllHandlers()
  • func (cf *ConfigFile) RemoveChangeHandler(id HandlerID) bool
  • func (cf *ConfigFile) Stat() (*storage.StorageInfo, error)
  • func (cf *ConfigFile) Write(data []byte) error
• type ConfigFileManager
  • func NewConfigFileManager(opts *ConfigFileManagerOpts) *ConfigFileManager
  • func (cfm *ConfigFileManager) ConfigFileAt(path string) *ConfigFile
• type ConfigFileManagerOpts
  • func DefaultConfigFileManagerOpts() *ConfigFileManagerOpts
  • func (cfmo *ConfigFileManagerOpts) IsBucketStorageEnabled() bool
• type HandlerID

Constants

const DefaultHandlerPriority int = 1000

DefaultHandlerPriority is used as the priority for any handlers added via AddChangeHandler

Variables

var NoBackingStore error = errors.New("Backing storage does not exist.")

NoBackingStore error is used when the config file's backing storage is missing

Types

type ChangeType

type ChangeType string

ChangeType is used to specifically categorize the change that was made on a ConfigFile

const (
	ChangeTypeCreated  ChangeType = "created"
	ChangeTypeModified ChangeType = "modified"
	ChangeTypeDeleted  ChangeType = "deleted"
)

ChangeType constants contain the different types of updates passed through the ConfigChangedHandler

type ConfigChangedHandler

type ConfigChangedHandler func(ChangeType, []byte)

ConfigChangedHandler is the func handler used to receive change updates about the config file. Both ChangeTypeCreated and ChangeTypeModified yield a valid []byte, while ChangeTypeDeleted yields a nil []byte.

type ConfigFile

type ConfigFile struct {
	// contains filtered or unexported fields
}

ConfigFile is representation of a configuration file that can be written to, read, and watched for updates

func NewConfigFile

func NewConfigFile(store storage.Storage, file string) *ConfigFile

NewConfigFile creates a new ConfigFile instance using a specific storage.Storage and path relative to the storage.

func (*ConfigFile) AddChangeHandler

func (cf *ConfigFile) AddChangeHandler(handler ConfigChangedHandler) HandlerID

AddChangeHandler accepts a ConfigChangedHandler function which will be called whenever the implementation detects that a change has been made. A unique HandlerID is returned that can be used to remove the handler if necessary.

func (*ConfigFile) AddPriorityChangeHandler

func (cf *ConfigFile) AddPriorityChangeHandler(handler ConfigChangedHandler, priority int) HandlerID

AddPriorityChangeHandler allows adding a config change handler with a specific priority. By default, any handlers added via AddChangeHandler have a default priority of 1000. The lower the priority, the sooner in the handler execution it will be called.

func (*ConfigFile) Delete

func (cf *ConfigFile) Delete() error

Delete removes the file from storage permanently.

func (*ConfigFile) Exists

func (cf *ConfigFile) Exists() (bool, error)

Exists returns true if the file exist. If an error other than a NotExist error is returned, the result will be false with the provided error.

func (*ConfigFile) Path

func (cf *ConfigFile) Path() string

Path returns the fully qualified path of the config file.

func (*ConfigFile) Read

func (cf *ConfigFile) Read() ([]byte, error)

Read will read the binary data from the file and return it. If an error is returned, the byte array will be nil.

func (*ConfigFile) Refresh

func (cf *ConfigFile) Refresh() ([]byte, error)

Refresh allows external callers to force reload the config file from internal storage. This is particularly useful when there exist no change listeners on the config, which would prevent the data cache from automatically updating on change

func (*ConfigFile) RemoveAllHandlers

func (cf *ConfigFile) RemoveAllHandlers()

RemoveAllHandlers removes all added handlers

func (*ConfigFile) RemoveChangeHandler

func (cf *ConfigFile) RemoveChangeHandler(id HandlerID) bool

RemoveChangeHandler removes the change handler with the provided identifier if it exists. True is returned if the handler was removed (it existed), false otherwise.

func (*ConfigFile) Stat

func (cf *ConfigFile) Stat() (*storage.StorageInfo, error)

Stat returns the StorageStats for the file.

func (*ConfigFile) Write

func (cf *ConfigFile) Write(data []byte) error

Write will write the binary data to the file.

type ConfigFileManager

type ConfigFileManager struct {
	// contains filtered or unexported fields
}

ConfigFileManager is a fascade for a central API used to create and watch config files.

func NewConfigFileManager

func NewConfigFileManager(opts *ConfigFileManagerOpts) *ConfigFileManager

NewConfigFileManager creates a new backing storage and configuration file manager

func (*ConfigFileManager) ConfigFileAt

func (cfm *ConfigFileManager) ConfigFileAt(path string) *ConfigFile

ConfigFileAt returns an existing configuration file for the provided path if it exists. Otherwise, a new instance is created and returned. Note that the path does not have to exist in order for the instance to be created. It can exist as a potential file path on the storage, and be written to later

type ConfigFileManagerOpts

type ConfigFileManagerOpts struct {
	// BucketStoreConfig is the local file location for the configuration used to
	// write and read configuration data to/from the bucket. The format of this
	// configuration file should be compatible with storage.NewBucketStorage
	BucketStoreConfig string

	// LocalConfigPath provides a backup location for storing the configuration
	// files
	LocalConfigPath string
}

ConfigFileManagerOpts describes how to configure the ConfigFileManager for serving configuration files

func DefaultConfigFileManagerOpts

func DefaultConfigFileManagerOpts() *ConfigFileManagerOpts

DefaultConfigFileManagerOpts returns the default configuration options for the config file manager

func (*ConfigFileManagerOpts) IsBucketStorageEnabled

func (cfmo *ConfigFileManagerOpts) IsBucketStorageEnabled() bool

IsBucketStorageEnabled returns true if bucket storage is enabled.

type HandlerID

type HandlerID string

HandlerID is a unique identifier assigned to a provided ConfigChangedHandler. This is used to remove a handler from the ConfigFile when it is no longer needed.