etcd

Documentation

Index

• Constants
• Variables
• func CloseDebug()
• func OpenDebug()
• func SetCurlChan(c chan string)
• type Client
  • func NewClient(machines []string) *Client
  • func NewClientFile(fpath string) (*Client, error)
  • func NewClientReader(reader io.Reader) (*Client, error)
  • func (c *Client) AddChild(key string, value string, ttl uint64) (*Response, error)
  • func (c *Client) AddChildDir(key string, ttl uint64) (*Response, error)
  • func (c *Client) CompareAndSwap(key string, value string, ttl uint64, prevValue string, prevIndex uint64) (*Response, error)
  • func (c *Client) Create(key string, value string, ttl uint64) (*Response, error)
  • func (c *Client) CreateDir(key string, ttl uint64) (*Response, error)
  • func (c *Client) Delete(key string) (*Response, error)
  • func (c *Client) DeleteAll(key string) (*Response, error)
  • func (c *Client) Get(key string, sort bool) (*Response, error)
  • func (c *Client) GetAll(key string, sort bool) (*Response, error)
  • func (c *Client) GetCluster() []string
  • func (c *Client) MarshalJSON() ([]byte, error)
  • func (c *Client) Set(key string, value string, ttl uint64) (*Response, error)
  • func (c *Client) SetCertAndKey(cert string, key string) error
  • func (c *Client) SetCluster(machines []string) bool
  • func (c *Client) SetConsistency(consistency string) error
  • func (c *Client) SetDir(key string, ttl uint64) (*Response, error)
  • func (c *Client) SetPersistence(writer io.Writer)
  • func (c *Client) SetScheme(scheme int) error
  • func (c *Client) SyncCluster() bool
  • func (c *Client) UnmarshalJSON(b []byte) error
  • func (c *Client) Update(key string, value string, ttl uint64) (*Response, error)
  • func (c *Client) UpdateDir(key string, ttl uint64) (*Response, error)
  • func (c *Client) Watch(key string, waitIndex uint64, receiver chan *Response, stop chan bool) (*Response, error)
  • func (c *Client) WatchAll(prefix string, waitIndex uint64, receiver chan *Response, stop chan bool) (*Response, error)
• type Cluster
• type Config
• type EtcdError
  • func (e EtcdError) Error() string
• type KeyValuePair
• type Response

Constants

const (
	HTTP = iota
	HTTPS
)

const (
	// Using strings rather than iota because the consistency level
	// could be persisted to disk, so it'd be better to use
	// human-readable values.
	STRONG_CONSISTENCY = "STRONG"
	WEAK_CONSISTENCY   = "WEAK"
)

See SetConsistency for how to use these constants.

Variables

var (
	VALID_GET_OPTIONS = validOptions{
		"recursive":  reflect.Bool,
		"consistent": reflect.Bool,
		"sorted":     reflect.Bool,
		"wait":       reflect.Bool,
		"waitIndex":  reflect.Uint64,
	}

	VALID_PUT_OPTIONS = validOptions{
		"prevValue": reflect.String,
		"prevIndex": reflect.Uint64,
		"prevExist": reflect.Bool,
	}

	VALID_POST_OPTIONS = validOptions{}

	VALID_DELETE_OPTIONS = validOptions{
		"recursive": reflect.Bool,
	}
)

Valid options for GET, PUT, POST, DELETE Using CAPITALIZED_UNDERSCORE to emphasize that these values are meant to be used as constants.

var (
	ErrWatchStoppedByUser = errors.New("Watch stopped by the user via stop channel")
)

Errors introduced by the Watch command.

Functions

func CloseDebug

func CloseDebug()

func OpenDebug

func OpenDebug()

func SetCurlChan

func SetCurlChan(c chan string)

SetCurlChan sets a channel to which cURL commands which can be used to re-produce requests are sent. This is useful for debugging.

Types

type Client

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

func NewClient

func NewClient(machines []string) *Client

NewClient create a basic client that is configured to be used with the given machine list.

func NewClientFile

func NewClientFile(fpath string) (*Client, error)

NewClientFile creates a client from a given file path. The given file is expected to use the JSON format.

func NewClientReader

func NewClientReader(reader io.Reader) (*Client, error)

NewClientReader creates a Client configured from a given reader. The config is expected to use the JSON format.

func (*Client) AddChild

func (c *Client) AddChild(key string, value string, ttl uint64) (*Response, error)

Add a new file with a random etcd-generated key under the given path.

func (*Client) AddChildDir

func (c *Client) AddChildDir(key string, ttl uint64) (*Response, error)

Add a new directory with a random etcd-generated key under the given path.

func (*Client) CompareAndSwap

func (c *Client) CompareAndSwap(key string, value string, ttl uint64, prevValue string, prevIndex uint64) (*Response, error)

func (*Client) Create

func (c *Client) Create(key string, value string, ttl uint64) (*Response, error)

Create creates a file with the given value under the given key. It succeeds only if the given key does not yet exist.

func (*Client) CreateDir

func (c *Client) CreateDir(key string, ttl uint64) (*Response, error)

UpdateDir creates a directory under the given key. It succeeds only if the given key does not yet exist.

func (*Client) Delete

func (c *Client) Delete(key string) (*Response, error)

Delete deletes the given key. If the key points to a directory, the method will fail.

func (*Client) DeleteAll

func (c *Client) DeleteAll(key string) (*Response, error)

DeleteAll deletes everything under the given key. If the key points to a file, the file will be deleted. If the key points to a directory, then everything under the directory, include all child directories, will be deleted.

func (*Client) Get

func (c *Client) Get(key string, sort bool) (*Response, error)

Get gets the file or directory associated with the given key. If the key points to a directory, files and directories under it will be returned in sorted or unsorted order, depending on the sort flag. Note that contents under child directories will not be returned. To get those contents, use GetAll.

func (*Client) GetAll

func (c *Client) GetAll(key string, sort bool) (*Response, error)

GetDir gets the all contents under the given key. If the key points to a file, the file is returned. If the key points to a directory, everything under it is returnd, including all contents under all child directories.

func (*Client) GetCluster

func (c *Client) GetCluster() []string

func (*Client) MarshalJSON

func (c *Client) MarshalJSON() ([]byte, error)

MarshalJSON implements the Marshaller interface as defined by the standard JSON package.

func (*Client) Set

func (c *Client) Set(key string, value string, ttl uint64) (*Response, error)

Set sets the given key to the given value.

func (*Client) SetCertAndKey

func (c *Client) SetCertAndKey(cert string, key string) error

func (*Client) SetCluster

func (c *Client) SetCluster(machines []string) bool

SetCluster updates config using the given machine list.

func (*Client) SetConsistency

func (c *Client) SetConsistency(consistency string) error

SetConsistency changes the consistency level of the client.

When consistency is set to STRONG_CONSISTENCY, all requests, including GET, are sent to the leader. This means that, assuming the absence of leader failures, GET requests are guaranteed to see the changes made by previous requests.

When consistency is set to WEAK_CONSISTENCY, other requests are still sent to the leader, but GET requests are sent to a random server from the server pool. This reduces the read load on the leader, but it's not guaranteed that the GET requests will see changes made by previous requests (they might have not yet been committed on non-leader servers).

func (*Client) SetDir

func (c *Client) SetDir(key string, ttl uint64) (*Response, error)

SetDir sets the given key to a directory.

func (*Client) SetPersistence

func (c *Client) SetPersistence(writer io.Writer)

SetPersistence sets a writer to which the config will be written every time it's changed.

func (*Client) SetScheme

func (c *Client) SetScheme(scheme int) error

func (*Client) SyncCluster

func (c *Client) SyncCluster() bool

SyncCluster updates config using the internal machine list.

func (*Client) UnmarshalJSON

func (c *Client) UnmarshalJSON(b []byte) error

UnmarshalJSON implements the Unmarshaller interface as defined by the standard JSON package.

func (*Client) Update

func (c *Client) Update(key string, value string, ttl uint64) (*Response, error)

Update updates the given key to the given value. It succeeds only if the given key already exists.

func (*Client) UpdateDir

func (c *Client) UpdateDir(key string, ttl uint64) (*Response, error)

UpdateDir updates the given key to a directory. It succeeds only if the given key already exists.

func (*Client) Watch

func (c *Client) Watch(key string, waitIndex uint64, receiver chan *Response, stop chan bool) (*Response, error)

Watch returns the first change to the given key since the given index. To watch for the latest change, set waitIndex = 0.

If a receiver channel is given, it will be a long-term watch. Watch will block at the channel. And after someone receive the channel, it will go on to watch that prefix. If a stop channel is given, client can close long-term watch using the stop channel

func (*Client) WatchAll

func (c *Client) WatchAll(prefix string, waitIndex uint64, receiver chan *Response, stop chan bool) (*Response, error)

WatchAll returns the first change under the given prefix since the given index. To watch for the latest change, set waitIndex = 0.

If the prefix points to a directory, any change under it, including all child directories, will be returned.

If a receiver channel is given, it will be a long-term watch. Watch will block at the channel. And after someone receive the channel, it will go on to watch that prefix. If a stop channel is given, client can close long-term watch using the stop channel

type Cluster

type Cluster struct {
	Leader   string   `json:"leader"`
	Machines []string `json:"machines"`
}

type Config

type Config struct {
	CertFile    string        `json:"certFile"`
	KeyFile     string        `json:"keyFile"`
	Scheme      string        `json:"scheme"`
	Timeout     time.Duration `json:"timeout"`
	Consistency string        `json: "consistency"`
}

type EtcdError

type EtcdError struct {
	ErrorCode int    `json:"errorCode"`
	Message   string `json:"message"`
	Cause     string `json:"cause,omitempty"`
}

func (EtcdError) Error

func (e EtcdError) Error() string

type KeyValuePair

type KeyValuePair struct {
	Key     string  `json:"key, omitempty"`
	Value   string  `json:"value,omitempty"`
	Dir     bool    `json:"dir,omitempty"`
	KVPairs kvPairs `json:"kvs,omitempty"`
	TTL     int64   `json:"ttl,omitempty"`
}

When user list a directory, we add all the node into key-value pair slice

type Response

type Response struct {
	Action    string  `json:"action"`
	Key       string  `json:"key"`
	Dir       bool    `json:"dir,omitempty"`
	PrevValue string  `json:"prevValue,omitempty"`
	Value     string  `json:"value,omitempty"`
	Kvs       kvPairs `json:"kvs,omitempty"`

	// If the key did not exist before the action,
	// this field should be set to true
	NewKey bool `json:"newKey,omitempty"`

	Expiration *time.Time `json:"expiration,omitempty"`

	// Time to live in second
	TTL int64 `json:"ttl,omitempty"`

	// The command index of the raft machine when the command is executed
	ModifiedIndex uint64 `json:"modifiedIndex"`
}

The response object from the server.