嘗試在 Heroku 服務器上的 Django 應用程序中遷移命令時出現問題

Question

我目前正在嘗試將我的 Django 項目部署到免費的 Heroku 服務器上。 當我嘗試執行以下命令時，出現錯誤heroku run python3 manage.py migrate 。 錯誤如下：

Running python3 manage.py makemigrations on ⬢ samstaskmanager... up, run.5214 (Free)
Traceback (most recent call last):
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 200, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/postgresql/base.py", line 187, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/psycopg2/__init__.py", line 127, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 22, in <module>
    main()
  File "manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 330, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 371, in execute
    output = self.handle(*args, **options)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/base.py", line 85, in wrapped
    res = handle_func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/core/management/commands/makemigrations.py", line 101, in handle
    loader.check_consistent_history(connection)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/loader.py", line 290, in check_consistent_history
    applied = recorder.applied_migrations()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/recorder.py", line 77, in applied_migrations
    if self.has_table():
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/migrations/recorder.py", line 55, in has_table
    with self.connection.cursor() as cursor:
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 259, in cursor
    return self._cursor()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 235, in _cursor
    self.ensure_connection()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
    self.connect()
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/base/base.py", line 200, in connect
    self.connection = self.get_new_connection(conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/utils/asyncio.py", line 26, in inner
    return func(*args, **kwargs)
  File "/app/.heroku/python/lib/python3.6/site-packages/django/db/backends/postgresql/base.py", line 187, in get_new_connection
    connection = Database.connect(**conn_params)
  File "/app/.heroku/python/lib/python3.6/site-packages/psycopg2/__init__.py", line 127, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
django.db.utils.OperationalError: could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?

這是我的settings.py：

Django settings for app project.

Generated by 'django-admin startproject' using Django 3.1.1.

For more information on this file, see
https://docs.djangoproject.com/en/3.1/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/3.1/ref/settings/
"""

from pathlib import Path
import os
#import django_heroku


# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/3.1/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'x0)a5try9uyd+t_l-5x#1*yfu@-$-(u665rz5@_m!!t5b7&d(6'

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = ['*']


# Application definition

INSTALLED_APPS = [
    'taskmanager.apps.TaskmanagerConfig',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'app.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [os.path.join(BASE_DIR,'templates')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'app.wsgi.application'


# Database
# https://docs.djangoproject.com/en/3.1/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'taskmanager',
        'USER': 'postgres',
        'PASSWORD': 'sam3778987',
        'HOST': 'localhost'
    }
}


# Password validation
# https://docs.djangoproject.com/en/3.1/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/3.1/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/3.1/howto/static-files/

STATIC_URL = '/static/'


STATIC_ROOT = os.path.join(BASE_DIR, 'static')


# Activate Django-Heroku.
#django_heroku.settings(locals())

我真的不知道為什么我一直收到這個錯誤，所以任何幫助將不勝感激。 也很抱歉這個凌亂的問題，這是我第一次寫一個。

Answer 1

在我看來，您正在嘗試在本地機器上使用 PostgreSQL 數據庫，並將您的應用程序托管在 Heroku 上。

我在最近創建的應用程序上使用 PostgreSQL 數據庫。 我最終創建了兩個settings.py文件（顯然名稱不同）。 一種是我在本地運行應用程序時使用的。 它具有以下數據庫連接代碼：

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': DB_NAME,
        'USER': MY_USERNAME,
        'PASSWORD': MY_PASSWORD,
        'HOST': HOST,
        'PORT': '5432',
    }
}

在我的生產settings.py （我稱之為settings_heroku_deploy.py並在部署期間在我的Procfile中使用）中，我有以下內容：

import dj_database_url
DATABASES = {}
DATABASES['default'] = dj_database_url.config(conn_max_age=600)
DATABASES['default']['ENGINE'] = 'django.db.backends.postgresql'

您可能已經知道這一點，但 PostgreSQL 數據庫的特征之一是它托管在服務器上。 因此，您使用的服務器需要在您運行應用程序的任何地方都可用。 我選擇將PostgreSQL 數據庫配置為Heroku 中的插件。 在部署期間，我使用dj_database_url包來自動配置我的連接，而在我的本地機器上，我必須明確提供用戶名、密碼等。

即使您可以讓您的應用程序連接到您的本地數據庫，也絕對值得將轉換為 Heroku PostgreSQL 數據庫。 它可以免費開始，而且肯定比在本地托管更靈活（除非您有一個實際的服務器可供您使用）。

Answer 2

這是由於您的 Postgres 數據庫。您可以在 settings.py 中找到它。 更改主機和端口設置。 也許您將主機和端口部分留空。 讓我知道它是否對你有幫助。

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'taskmanager',
        'USER': 'postgres',
        'PASSWORD': 'sam3778987',
        'HOST': 'localhost',
        'PORT': '5432',
    }
}

編輯：感謝分享您的 settings.py 代碼。 讓我知道它是否對你有幫助。