python之在 docker 中运行时无法从 python 连接到 influxdb

标题不完全准确，我愿意接受建议!

您可以在这里找到完整的 MCVE:https://github.com/timstoop/20170614-python-docker-influxdb-problem

测试:

• docker-engine 17.05.0~ce-0~ubuntu-xenial
• docker-compose 版本 1.13.0，构建 1719ceb

因此 docker-compose 启动了一个 influxdb 和一个小型 python3 应用程序。该应用程序唯一做的就是尝试连接到 influxdb，运行命令，如果失败，请等待 5 秒，然后重试。如果我运行 docker-compose up在此代码上，应用程序永远不会连接，它会不断重试。这些是它输出的日志行:

app_1       | 2017-06-14 18:57:36.892955 ticker Trying InfluxDB connection... 
app_1       | 2017-06-14 18:57:36.892977 ticker Influx host: 'influxdb' 
app_1       | 2017-06-14 18:57:36.892984 ticker Influx port: 8086 
app_1       | 2017-06-14 18:57:36.935112 ticker No InfluxDB connection yet. Waiting 5 seconds and retrying. 

但是，如果我使用 docker exec -ti <container name> /bin/sh 在该特定容器中打开一个 shell ，以下工作正常:

/ # python3 -u 
Python 3.6.1 (default, Jun  8 2017, 21:50:56)  
[GCC 6.3.0] on linux 
Type "help", "copyright", "credits" or "license" for more information. 
>>> from influxdb import InfluxDBClient 
>>> ci = InfluxDBClient(host='influxdb') 
>>> ci.get_list_database() 
[{'name': '_internal'}] 
>>> 

我确定我忽略了一些愚蠢的事情，但我无法解释为什么 app.py不会建立联系。因此，我无法修复该连接。如有任何建议，我们将不胜感激。

我的代码，供引用，如下所示。

应用.py:

#!/usr/bin/env python 
from influxdb import InfluxDBClient 
import datetime 
import sys 
import time 
import os 
import requests 
 
 
def output(msg): 
    # Convenience function to always show a correct output 
    now = datetime.datetime.now() 
    print("%s ticker %s" % (now, msg)) 
 
 
if __name__ == '__main__': 
    # Gather our settings 
    influx_host = os.getenv('INFLUX_HOST', 'localhost') 
    influx_port = os.getenv('INFLUX_PORT', '8086') 
    influx_user = os.getenv('INFLUX_USER', 'root') 
    influx_pass = os.getenv('INFLUX_PASS', 'root') 
    # Create our connections 
    # Check to make sure we can create a connection 
    got_if_connection = False 
    while not got_if_connection: 
        output('Trying InfluxDB connection...') 
        output("Influx host: %s" % influx_host) 
        output("Influx port: %s" % influx_port) 
        influx_client = InfluxDBClient(host=influx_host, port=influx_port, 
                                       username=influx_user, 
                                       password=influx_pass) 
        try: 
            influx_client.get_list_database() 
        except requests.exceptions.ConnectionError: 
            output('No InfluxDB connection yet. Waiting 5 seconds and '+ 
                   'retrying.') 
            time.sleep(5) 
        else: 
            got_if_connection = True 

docker 文件:

FROM python:alpine3.6 
MAINTAINER Tim Stoop <tim@kumina.nl> 
 
# Copy the script in 
COPY app.py /app.py 
COPY requirements.txt /requirements.txt 
 
# Install dependencies 
RUN pip install -r /requirements.txt 
 
 
CMD ["python3", "-u", "/app.py"] 

docker-compose.yml:

version: '2' 
services: 
  influxdb: 
    image: "influxdb:alpine" 
    ports: 
      - "8086:8086" 
  app: 
    build: . 
    links: 
      - influxdb 
    environment: 
      - INFLUX_HOST='influxdb' 

如果您需要任何其他信息，请告诉我!

请您参考如下方法:

从环境部分的 docker-compose.yml 文件中删除引号。

environment: 
  - INFLUX_HOST=influxdb