dlock

README

NAME

dlock - Easy to use, Distributed lock manager, written in Go.

Description

'dlock' provides command line tool to use for acquire distributed lock.

Focused on..

• Easy to use. One binary, No deploy, Only cloud.
• Configuration free.
• Almost ZERO pricing. (based on DynamoDB free tier)
• Scalable in the future.

Motivation

Startup projects, microserivces or etc, Some times we write a small batch program. In essence, we know it needs lock. But most case, it is enough lite and no time to make distributed lock. In early release, it will not causes problem, because programs takes enough short time. But it causes problem when we forget. So, I write Easy to Use distributed lock.

Requirement

AWS account only.

Usage

$ ./dlock
NAME:
   dlock - acquire 'lock' to following commands.

USAGE:
   dlock [global options] command [command options] [arguments...]
   
VERSION:
   0.0.0
   
COMMANDS:
     create-table	Create table then exit
     run		run command in distributed lock

GLOBAL OPTIONS:
   --region value, -r value		Specify Region name (default: "ap-northeast-1")
   --table value, -t value		Specify Table name
   --aws_access_key_id value		 [$AWS_ACCESS_KEY_ID]
   --aws_secret_access_key value	 [$AWS_SECRET_ACCESS_KEY]
   --help, -h				show help
   --version, -v			print the version

Install (on linux amd64)

$ curl -L https://github.com/unacowa/dlock/releases/download/pre-release/linux_amd64_dlock -o dlock
$ chmod +x dlock
$ sudo cp dlock /usr/local/bin

Example

Step 1: setup credential in ENV.

$ export AWS_ACCESS_KEY_ID=AKIxxxxxxxxxxxxxxxxx
$ export AWS_SECRET_ACCESS_KEY=Kxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Step 2: create table. (Maybe wait a seconds for created)

$ ./dlock --table dynamodb_go_lock create-table

Step 3: run

$ ./dlock --table dynamodb_go_lock run --domain example bash -c 'sleep 3; echo One' & ./dlock --table dynamodb_go_lock run --domain example bash -c 'sleep 3; echo Two'
failed acquire. transaction:fea09f48-c94b-4cb0-8b82-2479dee26564 running and not expires
One

Credential option

Uses AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY for access to AWS DynamoDB.

Both are passed from ENVIRONMENT or GLOBAL OPTION.

Contribution

Prepare container for library.

docker run -itd --name dynamodb_lock_go-gopath -v /go busybox

Install depandancy.

docker run --rm --volumes-from dynamodb_lock_go-gopath -v $PWD:/go/src/app -w /go/src/app golang:1.6 go-wrapper download

Build

docker run --rm --volumes-from dynamodb_lock_go-gopath -v $PWD:/go/src/app -w /go/src/app golang:1.6 go build -o 'dlock'

Test

Test uses 'REAL' dynamoDB. Create database as following, Before run.

docker run --rm --volumes-from dynamodb_lock_go-gopath -v $PWD:/go/src/app -w /go/src/app -e AWS_ACCESS_KEY_ID=AKIxxxxxxxxx -e AWS_SECRET_ACCESS_KEY=KVxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx golang:1.6 go run lock.go -t dynamodb_go_lock create-table

docker run --rm --volumes-from dynamodb_lock_go-gopath -v $PWD:/go/src/app -w /go/src/app -e AWS_ACCESS_KEY_ID=AKIxxxxxxxxx -e AWS_SECRET_ACCESS_KEY=KVxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx golang:1.6 go test .

Licence

MIT