README
¶
setddblock
setddblock is setlock like command line tool with AWS DynamoDB
Usage
$ setddblock -xN ddb://ddb_lock_table/lock_item_id your_command
Usage: setddblock [ -nNxX ] [--endpoint <endpoint>] [--debug --version] ddb://<table_name>/<item_id> your_command
Flags:
-n
No delay. If fn is locked by another process, setlock gives up.
-N
(Default.) Delay. If fn is locked by another process, setlock waits until it can obtain a new lock.
-x
If fn cannot be update-item (or put-item) or locked, setlock exits zero.
-X
(Default.) If fn cannot be update-item (or put-item) or locked, setlock prints an error message and exits nonzero.
--debug
show debug log
--endpoint string
If you switch remote, set AWS DynamoDB endpoint url.
--region string
aws region
--timeout string
set command timeout
--version
show version
the required IAM Policy is as follows:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"dynamodb:CreateTable",
"dynamodb:UpdateTimeToLive",
"dynamodb:PutItem",
"dynamodb:DescribeTable",
"dynamodb:GetItem",
"dynamodb:UpdateItem"
],
"Resource": "*"
}
]
}
If the lock table has already been created, dynamodb:CreateTable and dynamodb:UpdateTimeToLive are not required.
Install
binary packages
Homebrew tap
$ brew install mashiike/tap/setddblock
Usage as a library
setddblock.New(url string, optFns ...func(*setddblock.Options)) returns a DynamoDBLocker that satisfies the sync.Locker interface.
l, err := setddblock.New("ddb://ddb_lock_table/lock_item_id")
if err != nil {
// ...
}
func () {
l.Lock()
defer l.Unlock()
// ...
}()
Note: If Lock or Unlock fails, for example because you can't connect to DynamoDB, it will panic.
If you don't want it to panic, use LockWithError() and UnlockWithErr(). Alternatively, use the WithNoPanic option.
more infomation see go doc.
License
see LICENSE file.
Documentation
¶
Index ¶
- Variables
- func Recover(e interface{}) error
- func WithContext(ctx context.Context) func(opts *Options)
- func WithDelay(delay bool) func(opts *Options)
- func WithEndpoint(endpoint string) func(opts *Options)
- func WithLeaseDuration(d time.Duration) func(opts *Options)
- func WithLogger(logger Logger) func(opts *Options)
- func WithNoPanic() func(opts *Options)
- func WithRegion(region string) func(opts *Options)
- type DynamoDBLocker
- type Logger
- type Options
Constants ¶
This section is empty.
Variables ¶
var (
DefaultLeaseDuration = 10 * time.Second
)
Default values
Functions ¶
func WithContext ¶ added in v0.1.0
WithContext specifies the Context used by Lock() and Unlock().
func WithDelay ¶
WithDelay will delay the acquisition of the lock if it fails to acquire the lock. This is similar to the N option of setlock. The default is delay enalbed(true). Specify false if you want to exit immediately if Lock acquisition fails.
func WithEndpoint ¶
WithEndpoint is an endpoint specification option for Local development. Please enter the URL of DynamoDB Local etc.
func WithLeaseDuration ¶
WithLeaseDuration affects the heartbeat interval and TTL after Lock acquisition. The default is 10 seconds
func WithLogger ¶
WithLogger is a setting to enable the log output of DynamoDB Locker. By default, Logger that does not output anywhere is specified.
func WithNoPanic ¶
func WithNoPanic() func(opts *Options)
WithNoPanic changes the behavior so that it does not panic if an error occurs in the Lock () and Unlock () functions. Check the LastErr () function to see if an error has occurred when WithNoPanic is specified.
func WithRegion ¶
WithRegion specifies the AWS Region. Default AWS_DEFAULT_REGION env
Types ¶
type DynamoDBLocker ¶
type DynamoDBLocker struct {
// contains filtered or unexported fields
}
DynamoDB Locker implements the sync.Locker interface and provides a Lock mechanism using DynamoDB.
func New ¶
func New(urlStr string, optFns ...func(*Options)) (*DynamoDBLocker, error)
New returns *DynamoDBLocker
func (*DynamoDBLocker) ClearLastErr ¶ added in v0.3.0
func (l *DynamoDBLocker) ClearLastErr()
func (*DynamoDBLocker) LastErr ¶ added in v0.3.0
func (l *DynamoDBLocker) LastErr() error
func (*DynamoDBLocker) LockWithErr ¶
func (l *DynamoDBLocker) LockWithErr(ctx context.Context) (bool, error)
LockWithErr try get lock. The return value of bool indicates whether Lock has been released. If true, it is Lock Granted.
func (*DynamoDBLocker) UnlockWithErr ¶
func (l *DynamoDBLocker) UnlockWithErr(ctx context.Context) error
UnlockWithErr unlocks. Delete DynamoDB items
type Logger ¶
type Logger interface {
Print(v ...interface{})
Printf(format string, v ...interface{})
Println(v ...interface{})
}
Logger is a Logging interface used inside DynamoDB Locker
type Options ¶
type Options struct {
NoPanic bool
Logger Logger
Delay bool
Endpoint string
Region string
LeaseDuration time.Duration
// contains filtered or unexported fields
}
Options are for changing the behavior of DynamoDB Locker and are changed by the function passed to the New () function. See the WithXXX options for more information.
Source Files
Directories