在启动 Flask 之前如何检查 Redis 是否正在运行（如果没有运行则启动它）？

我是 Flask 新手，想要确保 redis 服务器正在运行，如果没有运行则启动它。这是我所拥有的：

@app.before_first_request
def initialize():
  cmd = 'src/redis-cli ping'
  p = subprocess.Popen(cmd,stdout=subprocess.PIPE)
  out, err = p.communicate()
  #if out.startswith('Could not connect to Redis'): #start redis here
  if err is not None: raise Exception(err)

但是，我收到错误“OSError：[Errno 2]没有这样的文件或目录”

有没有更简单的方法来检查redis服务器是否正在运行？

Use https://stackoverflow.com/a/12968704/538284 ping http://redis-py.readthedocs.org/en/latest/#redis.StrictRedis.pingredis的cmd：

import redis
from redis import ConnectionError
import logging

logging.basicConfig()
logger = logging.getLogger('redis')

rs = redis.Redis("localhost")
try:
    rs.ping()
except ConnectionError:
    logger.error("Redis isn't running. try `/etc/init.d/redis-server restart`")
    exit(0)

示例输出：

ERROR:redis:Redis isn't running. try `/etc/init.d/redis-server restart`