docker-service-reporter/updater.py

#!/usr/bin/env python3

import etcd
import time


class Updater:

  def __init__(self, host, port, prefix):
    self._client = etcd.Client(host=host, port=port)
    self._prefix = prefix


  def _write(self, key, value):
    self._client.write(self._prefix + key, value)


  def _write_obj(self, prefix, obj):
    for key, value in obj.items():
      new_prefix = "%s/%s" % (prefix, key)

      if isinstance(value, dict):
        self._write_obj(new_prefix, value)
      else:
        self._write(new_prefix, str(value))


  def _delete(self, key):
    try:
      self._client.delete(self._prefix + key, recursive=True)
    except etcd.EtcdKeyNotFound:
      pass


  def wipe(self):
    self._delete('')


  def add_containers(self, new_containers):
    for container in new_containers:
      name = container['name']
      print('Adding container %s' % name)
      self._write_obj('/containers/%s' % name, container)
      for k, v in container['labels'].items():
        self._write('/labels/%s/%s' % (k, name), v)
      for k, v in container['net']['addr'].items():
        self._write('/networks/%s/%s' % (k, name), v)
      self._write('/hosts/%s/%s' % (container['host'], name), name)
    self._notify_update()


  def remove_containers(self, old_containers):
    for container in old_containers:
      name = container['name']
      print('Removing container %s' % name)
      self._delete('/containers/%s' % name)
      for k, v in container['labels'].items():
        self._delete('/labels/%s/%s' % (k, name))
      for k, v in container['net']['addr'].items():
        self._delete('/networks/%s/%s' % (k, name)) 
      self._delete('/hosts/%s/%s' % (container['host'], name))
    self._notify_update()

  def _notify_update(self):
    print('Update completed', flush=True)
    self._write('/_updated', time.time())