Documentation
¶
Overview ¶
Package etcd3locker provides a locking mechanism using an etcd3 cluster. Tested on etcd 3.1/3.2./3.3
Package etcd3locker provides a locking mechanism using an etcd3 cluster ¶
To initialize a locker, a pre-existing connected etcd3 client must be present
client, err := clientv3.New(clientv3.Config{
Endpoints: []string{harness.Endpoint},
DialTimeout: 5 * time.Second,
})
For the most basic locker (e.g. non-shared etcd3 cluster / use default TTLs), a locker can be instantiated like the following:
locker, err := etcd3locker.New(client)
if err != nil {
return nil, fmt.Errorf("Failed to create etcd locker: %v", err.Error())
}
The locker will need to be included in composer that is used by tusd:
composer := tusd.NewStoreComposer() locker.UseIn(composer)
For a shared etcd3 cluster, you may want to modify the prefix that etcd3locker uses:
locker, err := etcd3locker.NewWithPrefix(client, "my-prefix")
if err != nil {
return nil, fmt.Errorf("Failed to create etcd locker: %v", err.Error())
}
For full control over all options, an etcd3.LockerOptions may be passed into etcd3.NewWithLockerOptions like the following example:
ttl := 15 // seconds
options := etcd3locker.NewLockerOptions(ttl, "my-prefix")
locker, err := etcd3locker.NewWithLockerOptions(client, options)
if err != nil {
return nil, fmt.Errorf("Failed to create etcd locker: %v", err.Error())
}
Tested on etcd 3.1/3.2/3.3
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( ErrLockNotHeld = errors.New("Lock not held") GrantTimeout = 1500 * time.Millisecond )
var ( DefaultTtl = 60 DefaultPrefix = "/tusd" )
Functions ¶
This section is empty.
Types ¶
type Etcd3Locker ¶
type Etcd3Locker struct {
// etcd3 client session
Client *etcd3.Client
// contains filtered or unexported fields
}
func New ¶
func New(client *etcd3.Client) (*Etcd3Locker, error)
New constructs a new locker using the provided client.
func NewWithLockerOptions ¶
func NewWithLockerOptions(client *etcd3.Client, opts LockerOptions) (*Etcd3Locker, error)
This method may be used if we want control over both prefix/session TTLs. This is used for testing in particular.
func NewWithPrefix ¶
func NewWithPrefix(client *etcd3.Client, prefix string) (*Etcd3Locker, error)
This method may be used if a different prefix is required for multi-tenant etcd clusters
func (*Etcd3Locker) LockUpload ¶
func (locker *Etcd3Locker) LockUpload(id string) error
LockUpload tries to obtain the exclusive lock.
func (*Etcd3Locker) UnlockUpload ¶
func (locker *Etcd3Locker) UnlockUpload(id string) error
UnlockUpload releases a lock.
func (*Etcd3Locker) UseIn ¶
func (locker *Etcd3Locker) UseIn(composer *tusd.StoreComposer)
UseIn adds this locker to the passed composer.
type LockerOptions ¶
type LockerOptions struct {
// contains filtered or unexported fields
}
func DefaultLockerOptions ¶
func DefaultLockerOptions() LockerOptions
DefaultLockerOptions() instantiates an instance of LockerOptions with default 60 second time to live and an etcd3 prefix of "/tusd"
func NewLockerOptions ¶
func NewLockerOptions(ttl int, prefix string) LockerOptions
NewLockerOptions instantiates an instance of LockerOptions with a provided TTL (time to live) and string prefix for keys to be stored in etcd3
func (*LockerOptions) Prefix ¶
func (l *LockerOptions) Prefix() string
Returns the string prefix used to store keys in etcd3
func (*LockerOptions) SetPrefix ¶
func (l *LockerOptions) SetPrefix(prefix string)
Set string prefix to be used in keys stored into etcd3 by the locker
func (*LockerOptions) SetTtl ¶
func (l *LockerOptions) SetTtl(ttl int)
Set etcd3 session TTL (time to live)
func (*LockerOptions) Ttl ¶
func (l *LockerOptions) Ttl() int
Returns the TTL (time to live) of sessions in etcd3
Source Files