docker - 不能使用带有psycopg2的另一个python3容器中的postgres容器

Question

我正在尝试使用docker-compose制作多容器docker应用程序。
这是我要完成的工作:我有一个python3应用，它从API调用(带有gunicorn服务器的fastAPI)输入一个数字列表，并将数字传递给返回的函数(实际上是ML模型)一个数字，该数字随后将作为结果发送回该API调用。那部分工作正常。当我引入了一个postgres容器来存储接收到的输入到postgres表中的输入时，问题就开始了，但我还没有添加应该从本地pgadmin4应用程序访问该postgres数据库数据的部分。
这是我到目前为止所做的:我正在使用“docker-compose.yml”文件来设置这两个容器，这里是:

version: '3.8'

services: 
    postgres:
        image: postgres:12.4
        restart: always
        environment:
            - POSTGRES_USER=postgres
            - POSTGRES_PASSWORD=postgres_password
            - POSTGRES_DATABASE=postgres

    docker_fastapi:
        # use the Dockerfile in the current directory.
        build: .
        ports:
            # 3000 is what I send API calls to
            - "3000:3000"
            # this is postgres's port
            - "5432:5432"
        environment: 
            # these are the environment variables that I am using inside psycop2 to make connection.
            - POSTGRES_HOST=postgres
            - POSTGRES_PORT=5432
            - POSTGRES_USER=postgres
            - POSTGRES_PASSWORD=postgres_password
            - POSTGRES_DATABASE=postgres

他
这是我在 psycopg2中使用这些环境变量的方式:

import os
from psycopg2 import connect

# making database connection using environement variables.
connection = connect(host=os.environ['POSTGRES_HOST'], port=os.environ['POSTGRES_PORT'],
                     user=os.environ['POSTGRES_USER'], password=os.environ['POSTGRES_PASSWORD'],
                     database=os.environ['POSTGRES_DATABASE']
                     )

这是Dockerfile:

FROM tiangolo/uvicorn-gunicorn:python3.8-slim
# slim = debian-based. Not using alpine because it has poor python3 support.
LABEL maintainer="Sebastian Ramirez <tiangolo@gmail.com>"


RUN apt-get update
RUN apt-get install -y libpq-dev gcc
# copy and install from requirements.txt file
COPY requirements.txt /app/requirements.txt
RUN pip install --no-cache-dir -r /app/requirements.txt
# remove all the dependency files to reduce the final image size
RUN apt-get autoremove -y gcc

# copying all the code files to the container's file system
COPY ./api /app/api

WORKDIR /app/api

EXPOSE 3000

ENTRYPOINT ["uvicorn"]

CMD ["api.main:app", "--host", "0.0.0.0", "--port", "3000"]

这是它为我发送的API调用生成的错误:

root@naveen-hp:/home/naveen/Videos/ML-Model-serving-with-fastapi-and-Docker# # docker-compose up
Starting ml-model-serving-with-fastapi-and-docker_docker_fastapi_1 ... done
Starting ml-model-serving-with-fastapi-and-docker_postgres_1       ... done
Attaching to ml-model-serving-with-fastapi-and-docker_postgres_1, ml-model-serving-with-fastapi-and-docker_docker_fastapi_1
postgres_1        | 
postgres_1        | PostgreSQL Database directory appears to contain a database; Skipping initialization
postgres_1        | 
postgres_1        | 2020-10-22 13:17:14.080 UTC [1] LOG:  starting PostgreSQL 12.4 (Debian 12.4-1.pgdg100+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 8.3.0-6) 8.3.0, 64-bit
postgres_1        | 2020-10-22 13:17:14.080 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 5432
postgres_1        | 2020-10-22 13:17:14.080 UTC [1] LOG:  listening on IPv6 address "::", port 5432
postgres_1        | 2020-10-22 13:17:14.092 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
postgres_1        | 2020-10-22 13:17:14.120 UTC [24] LOG:  database system was shut down at 2020-10-22 12:48:50 UTC
postgres_1        | 2020-10-22 13:17:14.130 UTC [1] LOG:  database system is ready to accept connections
docker_fastapi_1  | INFO:     Started server process [1]
docker_fastapi_1  | INFO:     Waiting for application startup.
docker_fastapi_1  | INFO:     Application startup complete.
docker_fastapi_1  | INFO:     Uvicorn running on http://0.0.0.0:3000 (Press CTRL+C to quit)
docker_fastapi_1  | INFO:     172.18.0.1:56094 - "POST /predict HTTP/1.1" 500 Internal Server Error
docker_fastapi_1  | ERROR:    Exception in ASGI application
docker_fastapi_1  | Traceback (most recent call last):
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/uvicorn/protocols/http/httptools_impl.py", line 391, in run_asgi
docker_fastapi_1  |     result = await app(self.scope, self.receive, self.send)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
docker_fastapi_1  |     return await self.app(scope, receive, send)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/fastapi/applications.py", line 179, in __call__
docker_fastapi_1  |     await super().__call__(scope, receive, send)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/applications.py", line 111, in __call__
docker_fastapi_1  |     await self.middleware_stack(scope, receive, send)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/middleware/errors.py", line 181, in __call__
docker_fastapi_1  |     raise exc from None
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/middleware/errors.py", line 159, in __call__
docker_fastapi_1  |     await self.app(scope, receive, _send)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/exceptions.py", line 82, in __call__
docker_fastapi_1  |     raise exc from None
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/exceptions.py", line 71, in __call__
docker_fastapi_1  |     await self.app(scope, receive, sender)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/routing.py", line 566, in __call__
docker_fastapi_1  |     await route.handle(scope, receive, send)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/routing.py", line 227, in handle
docker_fastapi_1  |     await self.app(scope, receive, send)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/routing.py", line 41, in app
docker_fastapi_1  |     response = await func(request)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/fastapi/routing.py", line 182, in app
docker_fastapi_1  |     raw_response = await run_endpoint_function(
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/fastapi/routing.py", line 135, in run_endpoint_function
docker_fastapi_1  |     return await run_in_threadpool(dependant.call, **values)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/site-packages/starlette/concurrency.py", line 34, in run_in_threadpool
docker_fastapi_1  |     return await loop.run_in_executor(None, func, *args)
docker_fastapi_1  |   File "/usr/local/lib/python3.8/concurrent/futures/thread.py", line 57, in run
docker_fastapi_1  |     result = self.fn(*self.args, **self.kwargs)
docker_fastapi_1  |   File "/app/api/main.py", line 83, in predict
docker_fastapi_1  |     insert_into_db(X)
docker_fastapi_1  |   File "/app/api/main.py", line 38, in insert_into_db
docker_fastapi_1  |     cursor.execute(f"INSERT INTO public.\"API_Test\""
docker_fastapi_1  | IndexError: index 1 is out of bounds for axis 0 with size 1

这是我发送API调用的方式:

curl -X POST "http://0.0.0.0:3000/predict" -H "accept: application/json" -H "Content-Type: application/json" -d "{\"input_data\":[[
       1.354e+01, 1.436e+01, 8.746e+01, 5.663e+02, 9.779e-02, 8.129e-02,
       6.664e-02, 4.781e-02, 1.885e-01, 5.766e-02, 2.699e-01, 7.886e-01,
       2.058e+00, 2.356e+01, 8.462e-03, 1.460e-02, 2.387e-02, 1.315e-02,
       1.980e-02, 2.300e-03, 1.511e+01, 1.926e+01, 9.970e+01, 7.112e+02,
       1.440e-01, 1.773e-01, 2.390e-01, 1.288e-01, 2.977e-01, 7.259e-02]]}"

当我使用不带第二个postgres容器的AWS RDS的postgres实例的凭据来构建它并直接在 psycopg2.connect()内部指定凭据而不使用环境变量和docker-compose并直接使用上面显示的Dockerfile进行构建时，此方法可以按预期工作；因此，我将接收到的数据插入postgres的代码大概很好。当我引入第二个容器时，问题就开始了。是什么原因导致此类错误，以及如何解决此问题？

Answer 1

您必须添加网络网络和depend_on 标志。试试这个:

version: '3.8'

services: 
    postgres:
        image: postgres:12.4
        restart: always
        environment:
            - POSTGRES_USER=postgres
            - POSTGRES_PASSWORD=postgres_password
            - POSTGRES_DB=postgres
        networks:
            - default

    docker_fastapi:
        # use the Dockerfile in the current directory.
        build: .
        ports:
            # 3000 is what I send API calls to
            - "3000:3000"
            # this is postgres's port
            # no need for this
            # - "5432:5432"
        networks:
            - default
        depends_on:
            - postgres
        # no need for this
        # environment: 
            # these are the environment variables that I am using inside psycop2 to make connection.
            # - POSTGRES_HOST=postgres
            # - POSTGRES_PORT=5432
            # - POSTGRES_USER=postgres
            # - POSTGRES_PASSWORD=postgres_password
            # - POSTGRES_DATABASE=postgres