slvwolf / etcdlock

Command line lock using Etcd

EtcdLock

• Dependencies: python-etcd
• Requires Python 3.5

Command line usage

Command line lock using Etcd

positional arguments:
  cmd

optional arguments:
  -h, --help           show this help message and exit
  --key KEY            Key used for lock (Default: /lock/default)
  --id ID              Client id for the lock. This should be unique
                       for each client (Default: generated)
  --host HOST          Etcd server host (Default: 127.0.0.1)
  --port PORT          Etcd server port (Default: 4001)
  --protocol PROTOCOL  Etcd server protocol (Default: http)

Example:

etcdlock --key /some/key/here --id someid sleep 10 &
etcdlock --key /some/key/here --id anotherid ls

Usage in Python

lock = EtcdLock("/locks/my_lock", "client_id")
lock.acquire()
...
lock.release()

# Or

with EtcdLock("/locks/my_lock", "client_id"):
    ...

Known limitation

• If lock is forcefully changed the original acquirer will get an exception when releasing the lock
• Client id can not be shared with different processes without side-effects
• Killing etcdlock during execution might leave the lock in a locked state. However, same client id can still access the lock.