Distributed KV Store - PoC / Experiements

Example use case of using Consul KV to retrieve Configuration values to have a stateless micro service.

Python based:

• Consul agent running at <consul_ip>.
• Django based micro service.
• Manage DB configuration in settings.py of the micro service.

Steps:

• Add database configuration key values to Consul:

  curl -X PUT -d 'django.db.backends.mysql' http://<consul_ip>:8500/v1/kv/<service_name>/database/engine
  curl -X PUT -d '<DB_NAME>' http://<consul_ip>:8500/v1/kv/<service_name>/database/name
  curl -X PUT -d '<DB_IP>' http://<consul_ip>:8500/v1/kv/<service_name>/database/ip
  curl -X PUT -d 3306 http://<consul_ip>8500/v1/kv/<service_name>/database/port
  curl -X PUT -d '<DB_USERNAME>' http://<consul_ip>:8500/v1/kv/<service_name>/database/username
  curl -X PUT -d '<DB_PASSWORD>' http://<consul_ip>:8500/v1/kv/<service_name>/database/password

  In settings.py of Django, retrieve the DB configuration values as:

  import envconsul

  ENV_CONSUL = envconsul.EnvConsul(
   service_name='<service_name>',
   host='<consul_ip>',
   port=8500,
  )

  DB_ENGINE = ENV_CONSUL.get_str('/database/engine')
  DB_NAME = ENV_CONSUL.get_str('/database/name')
  DB_IP = ENV_CONSUL.get_str('/database/ip')
  DB_PORT = ENV_CONSUL.get('/database/port')
  DB_USERNAME = ENV_CONSUL.get_str('/database/username')
  DB_PASSWORD = ENV_CONSUL.get_str('/database/password')

  # Use the values obtained from Consul in DATABASES config of Django.

  DATABASES = {
   'default': {
   'ENGINE': DB_ENGINE,
   'NAME': DB_NAME,
   'HOST': DB_IP,
   'PORT': DB_PORT,
   'USER': DB_USERNAME,
   'PASSWORD': DB_PASSWORD,
   },
  }

  This way, DB configuration can easily be passed to all the micro services.

2.