我创建了一个具有Postgres数据库的 Django-Python应用程序。它可以在我的PC以及任何其他基于Windows的系统中正常工作。 我正在尝试使用K8托管应用程序。 我已经成功设置了postgres容器。
但是当我尝试创建Django-Python容器并尝试启动它时，它向我显示了这种错误：
服务器是否在主机“ 127.0.0.1”上运行并接受 端口5432上的TCP / IP连接？
postgres容器的部署和服务Yaml：
---
# Deployment for the PostgreSQL container
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgresql
namespace: trojanwall
labels:
app: postgres-db
spec:
replicas: 1
selector:
matchLabels:
app: postgres-db
strategy:
type: Recreate
template:
metadata:
labels:
app: postgres-db
tier: postgreSQL
spec:
containers:
- name: postgresql
image: postgres:10.3
ports:
- containerPort: 5432
env:
- name: POSTGRES_USER
valueFrom:
secretKeyRef:
name: postgres-db-credentials
key: user
- name: POSTGRES_PASSWORD
valueFrom:
secretKeyRef:
name: postgres-db-credentials
key: password
- name: POSTGRES_DB
value: 'postgres'
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgresql-volume-mount
resources:
requests:
memory: "64Mi"
cpu: "250m"
limits:
memory: "128Mi"
cpu: "500m"
volumes:
- name: postgresql-volume-mount
persistentVolumeClaim:
claimName: postgres-pv-claim
---
# Service for the PostgreSQL container
apiVersion: v1
kind: Service
metadata:
name: postgresql
namespace: trojanwall
labels:
app: postgres-db
spec:
type: ClusterIP
ports:
- port: 5432
targetPort: 5432
protocol: TCP
selector:
app: postgres-db
tier: postgreSQL
Postgres容器的日志：
2020-09-23 15:39:58.034 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
2020-09-23 15:39:58.034 UTC [1] LOG: listening on IPv6 address "::", port 5432
2020-09-23 15:39:58.038 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2020-09-23 15:39:58.049 UTC [23] LOG: database system was shut down at 2020-09-23 15:37:17 UTC
2020-09-23 15:39:58.053 UTC [1] LOG: database system is ready to accept connections
2020-09-23 15:47:12.845 UTC [1] LOG: received smart shutdown request
2020-09-23 15:47:12.846 UTC [1] LOG: worker process: logical replication launcher (PID 29) exited with exit code 1
2020-09-23 15:47:12.846 UTC [24] LOG: shutting down
2020-09-23 15:47:12.851 UTC [1] LOG: database system is shut down
2020-09-23 15:47:13.123 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
2020-09-23 15:47:13.123 UTC [1] LOG: listening on IPv6 address "::", port 5432
2020-09-23 15:47:13.126 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2020-09-23 15:47:13.134 UTC [24] LOG: database system was shut down at 2020-09-23 15:47:12 UTC
2020-09-23 15:47:13.138 UTC [1] LOG: database system is ready to accept connections
2020-09-23 15:47:25.722 UTC [1] LOG: received smart shutdown request
2020-09-23 15:47:25.724 UTC [1] LOG: worker process: logical replication launcher (PID 30) exited with exit code 1
2020-09-23 15:47:25.725 UTC [25] LOG: shutting down
2020-09-23 15:47:25.730 UTC [1] LOG: database system is shut down
2020-09-23 15:47:25.925 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
2020-09-23 15:47:25.925 UTC [1] LOG: listening on IPv6 address "::", port 5432
2020-09-23 15:47:25.927 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2020-09-23 15:47:25.937 UTC [23] LOG: database system was shut down at 2020-09-23 15:47:25 UTC
2020-09-23 15:47:25.941 UTC [1] LOG: database system is ready to accept connections
现在，当我尝试部署Django-Python容器时，它不会连接到数据库容器。
Django-Python应用程序部署和服务YAML文件：
---
# Deployment for the Django-Python application container
apiVersion: apps/v1
kind: Deployment
metadata:
name: trojanwall-django
namespace: trojanwall
labels:
app: django
spec:
replicas: 1
selector:
matchLabels:
app: django
template:
metadata:
labels:
app: django
spec:
containers:
- name: trojanwall-django
image: arbabu/trojan-wall:v3.0
imagePullPolicy: Always
ports:
- containerPort: 8000
env:
- name: POSTGRES_USER
valueFrom:
secretKeyRef:
name: postgres-db-credentials
key: user
- name: POSTGRES_PASSWORD
valueFrom:
secretKeyRef:
name: postgres-db-credentials
key: password
- name: POSTGRES_DB
value: 'postgres'
- name: DATABASE_URL
value: postgres://$(POSTGRES_USER):$(POSTGRES_PASSWORD)@postgresql:5432/$(POSTGRES_DB)
- name: DJANGO_SETTINGS_MODULE
value: 'TestProject.settings'
- name: SECRET_KEY
valueFrom:
secretKeyRef:
name: django-secret-key
key: secret_key
resources:
requests:
memory: "64Mi"
cpu: "250m"
limits:
memory: "128Mi"
cpu: "500m"
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgresql-volume-mount
volumes:
- name: postgresql-volume-mount
persistentVolumeClaim:
claimName: postgres-pv-claim
---
# Service for the Django-Python application container
apiVersion: v1
kind: Service
metadata:
name: trojanwall-django
namespace: trojanwall
labels:
app: django
spec:
ports:
- port: 8000
targetPort: 8000
protocol: TCP
type: NodePort
selector:
app: django
此步骤之后，pod确实开始运行，但是一旦我将bash拖入Django容器并运行命令：
python3 manage.py迁移
它向我显示此错误：
root@trojanwall-django-7df4bc7759-89bgv:/TestProject# python3 manage.py migrate
Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
self.connect()
File "/usr/local/lib/python3.8/site-packages/django/utils/asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/django/db/backends/base/base.py", line 200, in connect
self.connection = self.get_new_connection(conn_params)
File "/usr/local/lib/python3.8/site-packages/django/utils/asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/django/db/backends/postgresql/base.py", line 187, in get_new_connection
connection = Database.connect(**conn_params)
File "/usr/local/lib/python3.8/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 "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 21, in <module>
main()
File "manage.py", line 17, in main
execute_from_command_line(sys.argv)
File "/usr/local/lib/python3.8/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
utility.execute()
File "/usr/local/lib/python3.8/site-packages/django/core/management/__init__.py", line 395, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/usr/local/lib/python3.8/site-packages/django/core/management/base.py", line 330, in run_from_argv
self.execute(*args, **cmd_options)
File "/usr/local/lib/python3.8/site-packages/django/core/management/base.py", line 371, in execute
output = self.handle(*args, **options)
File "/usr/local/lib/python3.8/site-packages/django/core/management/base.py", line 85, in wrapped
res = handle_func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/django/core/management/commands/migrate.py", line 92, in handle
executor = MigrationExecutor(connection, self.migration_progress_callback)
File "/usr/local/lib/python3.8/site-packages/django/db/migrations/executor.py", line 18, in __init__
self.loader = MigrationLoader(self.connection)
File "/usr/local/lib/python3.8/site-packages/django/db/migrations/loader.py", line 53, in __init__
self.build_graph()
File "/usr/local/lib/python3.8/site-packages/django/db/migrations/loader.py", line 216, in build_graph
self.applied_migrations = recorder.applied_migrations()
File "/usr/local/lib/python3.8/site-packages/django/db/migrations/recorder.py", line 77, in applied_migrations
if self.has_table():
File "/usr/local/lib/python3.8/site-packages/django/db/migrations/recorder.py", line 55, in has_table
with self.connection.cursor() as cursor:
File "/usr/local/lib/python3.8/site-packages/django/utils/asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/django/db/backends/base/base.py", line 259, in cursor
return self._cursor()
File "/usr/local/lib/python3.8/site-packages/django/db/backends/base/base.py", line 235, in _cursor
self.ensure_connection()
File "/usr/local/lib/python3.8/site-packages/django/utils/asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
self.connect()
File "/usr/local/lib/python3.8/site-packages/django/db/utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/usr/local/lib/python3.8/site-packages/django/db/backends/base/base.py", line 219, in ensure_connection
self.connect()
File "/usr/local/lib/python3.8/site-packages/django/utils/asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/django/db/backends/base/base.py", line 200, in connect
self.connection = self.get_new_connection(conn_params)
File "/usr/local/lib/python3.8/site-packages/django/utils/asyncio.py", line 26, in inner
return func(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/django/db/backends/postgresql/base.py", line 187, in get_new_connection
connection = Database.connect(**conn_params)
File "/usr/local/lib/python3.8/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 "127.0.0.1" and accepting
TCP/IP connections on port 5432?
有人知道如何解决吗？
这里是对settings.py文件的数据库配置的引用。
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'NAME': os.environ.get('POSTGRES_NAME', 'postgres'),
'USER': os.environ.get('POSTGRES_USER', 'postgres'),
'PASSWORD': os.environ.get('POSTGRES_PASSWORD', 'postgres'),
'HOST': os.getenv('POSTGRES_SERVICE_HOST','127.0.0.1'),
'PORT': os.getenv('POSTGRES_SERVICE_PORT',5432)
}
}
秘密yaml文件：
---
# Secrets for the Database Credential Management
apiVersion: v1
kind: Secret
metadata:
name: postgres-db-credentials
namespace: trojanwall
labels:
app: postgres-db
type: opaque
data:
user: cG9zdGdyZXM=
password: cG9zdGdyZXM=
答案 0 :(得分：2)
kind: Service
metadata:
name: postgresql
namespace: trojanwall
labels:
app: postgres-db
spec:
type: ClusterIP
由于PostreSQL实例的服务类型为ClusterIP，因此您为PostreSQL实例提供的服务将从Kubernetes群集分配新的IP地址。很好。
但是您的Python应用程序必须通过那个IP地址连接到PostgreSQL，并且不连接到127.0.0.1。
在setting.py的下面一行中，看起来您的PostgreSQL实例的IP地址可以被覆盖，必须对其进行更改以反映Kubernetes集群中的IP。
'HOST': os.getenv('POSTGRES_SERVICE_HOST','127.0.0.1'),
为应用更新您的Deployment，以包含POSTGRES_SERVICE_HOST的环境值。
示例：
spec:
containers:
- name: trojanwall-django
image: arbabu/trojan-wall:v3.0
imagePullPolicy: Always
ports:
- containerPort: 8000
env:
- name: POSTGRES_SERVICE_HOST
value: "<INSERT YOUR IP ADDRESS>" # update this to reflect your IP
- name: POSTGRES_USER
valueFrom:
secretKeyRef:
name: postgres-db-credentials
key: user
- name: POSTGRES_PASSWORD
valueFrom:
secretKeyRef:
name: postgres-db-credentials
key: password