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У меня есть приложение flask с базой данных mongodb, которое я пытаюсь развернуть на мини-кубе.

Я упаковал оба приложения и определил, что они работают без оркестровки.

Я обязательно запускаю mongodb перед колбой.

Однако при запуске в kubernetes я получаю следующую ошибку. журналы kubectl flaskweb-развертывание-7f6775bc8f-7q72j

 Traceback (most recent call last):  File "run.py", line 1, in lt;modulegt;  from app import web_app, socketio  File "/code/app/__init__.py", line 18, in lt;modulegt;  from .main import main as main_blueprint  File "/code/app/main/__init__.py", line 5, in lt;modulegt;  from . import routes, events  File "/code/app/main/routes.py", line 8, in lt;modulegt;  from .models import eInstance, eMessage  File "/code/app/main/models.py", line 24, in lt;modulegt;  if eInstance.objects().first() is None:  File "/usr/local/lib/python3.8/dist-packages/mongoengine/queryset/manager.py", line 38, in __get__  queryset = queryset_class(owner, owner._get_collection())  File "/usr/local/lib/python3.8/dist-packages/mongoengine/document.py", line 223, in _get_collection  if cls._meta.get("auto_create_index", True) and db.client.is_primary:  File "/usr/local/lib/python3.8/dist-packages/pymongo/mongo_client.py", line 1088, in is_primary  return self._server_property('is_writable')  File "/usr/local/lib/python3.8/dist-packages/pymongo/mongo_client.py", line 889, in _server_property  server = self._topology.select_server(  File "/usr/local/lib/python3.8/dist-packages/pymongo/topology.py", line 244, in select_server  return random.choice(self.select_servers(selector,  File "/usr/local/lib/python3.8/dist-packages/pymongo/topology.py", line 202, in select_servers  server_descriptions = self._select_servers_loop(  File "/usr/local/lib/python3.8/dist-packages/pymongo/topology.py", line 218, in _select_servers_loop  raise ServerSelectionTimeoutError( pymongo.errors.ServerSelectionTimeoutError: 10.97.8.16:27017: [Errno 111] Connection refused, Timeout: 30s, Topology Description: lt;TopologyDescription id: 6187e39295442839a2d95a49, topology_type: Single, servers: [lt;ServerDescription ('10.97.8.16', 27017) server_type: Unknown, rtt: None, error=AutoReconnect('10.97.8.16:27017: [Errno 111] Connection refused')gt;]gt;  

Я просмотрел все сообщения, которые я могу найти, относящиеся к этой проблеме, но не могу сопоставить ни одну из этих проблем с моей реализацией.

Dockerfiles mongodb

 FROM ubuntu:18.04 RUN apt update; apt install -y gnupg2  RUN apt install -y software-properties-common  # Installation RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4  RUN add-apt-repository 'deb [arch=amd64] https://repo.mongodb.org/apt/ubuntu bionic/mongodb-org/4.0 multiverse'  RUN apt-get update amp;amp; apt install -y mongodb-org  RUN mkdir /data  RUN mkdir /data/db   # Start db #RUN mongod --bind_ip=0.0.0.0 amp;  EXPOSE 27017 # Set entrypoint ENTRYPOINT ["usr/bin/mongod", "--bind_ip=0.0.0.0"]  

колба питона

 FROM ubuntu:latest RUN apt update; apt install -y gnupg2 WORKDIR /code COPY . /code/ RUN apt install -y python3-pip RUN pip3 install -r requirements.txt ENV PYTHONPATH /code EXPOSE 8080 ENTRYPOINT [ "python3" ] CMD [ "run.py" ]  

yaml files for deployment and service

 apiVersion: apps/v1 kind: Deployment metadata:  name: mongodb-deployment  labels:  app: mongodb spec:  replicas: 1  selector:  matchLabels:  app: mongodb  template:  metadata:  labels:  app: mongodb  spec:  containers:  - name: mongodb  image: mongodb:v1  imagePullPolicy: Never  ports:  - containerPort: 27017  volumes:  - name: mongo-persistent-storage  mountPath: /data/db  volumes:  - name: mongo-persistent-storage  

serviceDB.yaml

 apiVersion: v1 kind: Service metadata:  labels:  name: mongodb-service  name: mongodb-service spec:  ports:  - port: 27017  targetPort: 27017  selector:  app: mongodb  

webserver-deploy.yaml

 apiVersion: apps/v1 kind: Deployment metadata:  name: flaskweb-deployment spec:  replicas: 3  selector:  matchLabels:  app: flaskweb  template:  metadata:  labels:  app: flaskweb  spec:  containers:  - name: flaskweb  image: flaskweb:v1  ports:  - containerPort: 8080  

serviceWEB.yaml

 apiVersion: v1 kind: Service metadata:  name: flaskweb-service spec:  selector:  app: flaskweb  type: NodePort  ports:  - protocol: "TCP"  port: 8080  targetPort: 8080  nodePort: 30100  

kubectl get pods

 NAME READY STATUS RESTARTS AGE flaskweb-deployment-7f6775bc8f-7q72j 0/1 Error 1 (40s ago) 74s flaskweb-deployment-7f6775bc8f-lpwlz 0/1 Error 1 (40s ago) 74s flaskweb-deployment-7f6775bc8f-pvnjz 0/1 Error 1 (40s ago) 74s mongodb-deployment-867998dcff-786tv 1/1 Running 0 6m29s  NAME READY STATUS RESTARTS AGE flaskweb-deployment-7f6775bc8f-7q72j 0/1 CrashLoopBackOff 9 (94s ago) 27m flaskweb-deployment-7f6775bc8f-lpwlz 0/1 CrashLoopBackOff 9 (85s ago) 27m flaskweb-deployment-7f6775bc8f-pvnjz 0/1 CrashLoopBackOff 9 (111s ago) 27m mongodb-deployment-867998dcff-786tv 1/1 Running 0 33m  

kubectl get services

 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE flaskweb-service NodePort 10.105.225.55 lt;nonegt; 8080:30100/TCP 2s kubernetes ClusterIP 10.96.0.1 lt;nonegt; 443/TCP 23h mongodb-service ClusterIP 10.97.8.16 lt;nonegt; 27017/TCP 24m  

mongodb settings in config.py

 MONGODB_SETTINGS = {'db': 'mongodb', 'host': '10.97.8.16', 'port': 27017}   

kubectl describe pod flaskweb-deployment-7f6775bc8f-7q72j

 Name: flaskweb-deployment-7f6775bc8f-7q72j Namespace: default Priority: 0 Node: minikube/192.168.49.2 Start Time: Sun, 07 Nov 2021 14:31:31  0000 Labels: app=flaskweb  pod-template-hash=7f6775bc8f Annotations: lt;nonegt; Status: Running IP: 172.17.0.6 IPs:  IP: 172.17.0.6 Controlled By: ReplicaSet/flaskweb-deployment-7f6775bc8f Containers:  flaskweb:  Container ID: docker://93d1a5c0dfb69feadb8b1c252a3ad4635342e5117c2814f838e651cf0e9f13d9  Image: flaskweb:v1  Image ID: docker://sha256:eaf719a9964b4de784f2a56951e9d058e41f7201a7db25d26a5100539841e25b  Port: 8080/TCP  Host Port: 0/TCP  State: Waiting  Reason: CrashLoopBackOff  Last State: Terminated  Reason: Error  Exit Code: 1  Started: Sun, 07 Nov 2021 14:57:17  0000  Finished: Sun, 07 Nov 2021 14:57:49  0000  Ready: False  Restart Count: 9  Environment: lt;nonegt;  Mounts:  /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-hchq9 (ro) Conditions:  Type Status  Initialized True   Ready False   ContainersReady False   PodScheduled True  Volumes:  kube-api-access-hchq9:  Type: Projected (a volume that contains injected data from multiple sources)  TokenExpirationSeconds: 3607  ConfigMapName: kube-root-ca.crt  ConfigMapOptional: lt;nilgt;  DownwardAPI: true QoS Class: BestEffort Node-Selectors: lt;nonegt; Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s  node.kubernetes.io/unreachable:NoExecute op=Exists for 300s Events:  Type Reason Age From Message  ---- ------ ---- ---- -------  Normal Scheduled 29m default-scheduler Successfully assigned default/flaskweb-deployment-7f6775bc8f-7q72j to minikube  Normal Created 25m (x5 over 29m) kubelet Created container flaskweb  Normal Started 25m (x5 over 29m) kubelet Started container flaskweb  Normal Pulled 9m3s (x9 over 29m) kubelet Container image "flaskweb:v1" already present on machine  Warning BackOff 3m58s (x94 over 27m) kubelet Back-off restarting failed container  

Edit: I matched the selector using app instead of name in the service yaml.

Still getting the following errors:

 Traceback (most recent call last):  File "run.py", line 1, in lt;modulegt;  from app import web_app, socketio  File "/code/app/__init__.py", line 18, in lt;modulegt;  from .main import main as main_blueprint  File "/code/app/main/__init__.py", line 5, in lt;modulegt;  from . import routes, events  File "/code/app/main/routes.py", line 8, in lt;modulegt;  from .models import eInstance, eMessage  File "/code/app/main/models.py", line 24, in lt;modulegt;  if eInstance.objects().first() is None:  File "/usr/local/lib/python3.8/dist-packages/mongoengine/queryset/manager.py", line 38, in __get__  queryset = queryset_class(owner, owner._get_collection())  File "/usr/local/lib/python3.8/dist-packages/mongoengine/document.py", line 223, in _get_collection  if cls._meta.get("auto_create_index", True) and db.client.is_primary:  File "/usr/local/lib/python3.8/dist-packages/pymongo/mongo_client.py", line 1088, in is_primary  return self._server_property('is_writable')  File "/usr/local/lib/python3.8/dist-packages/pymongo/mongo_client.py", line 889, in _server_property  server = self._topology.select_server(  File "/usr/local/lib/python3.8/dist-packages/pymongo/topology.py", line 244, in select_server  return random.choice(self.select_servers(selector,  File "/usr/local/lib/python3.8/dist-packages/pymongo/topology.py", line 202, in select_servers  server_descriptions = self._select_servers_loop(  File "/usr/local/lib/python3.8/dist-packages/pymongo/topology.py", line 218, in _select_servers_loop  raise ServerSelectionTimeoutError( pymongo.errors.ServerSelectionTimeoutError: 10.97.8.16:27017: timed out, Timeout: 30s, Topology Description: lt;TopologyDescription id: 61880d44d1e4d98ec7db8557, topology_type: Single, servers: [lt;ServerDescription ('10.97.8.16', 27017) server_type: Unknown, rtt: None, error=NetworkTimeout('10.97.8.16:27017: timed out')gt;]gt;  

ОКОНЧАТЕЛЬНОЕ РЕДАКТИРОВАНИЕ: В системе заканчивались ресурсы. помогла обрезка докерской системы.

Проблема здесь связана с настройкой вашей службы для mongodb.

 ~$ kubectl explain service.spec.selector KIND: Service VERSION: v1  FIELD: selector lt;map[string]stringgt;  DESCRIPTION:  Route service traffic to pods with label keys and values matching this  selector. If empty or not present, the service is assumed to have an  external process managing its endpoints, which Kubernetes will not modify.  Only applies to types ClusterIP, NodePort, and LoadBalancer. Ignored if  type is ExternalName. More info:  https://kubernetes.io/docs/concepts/services-networking/service/  

как вы можете видеть из вышесказанного, селектор использует ключи и значения меток модулей, чтобы узнать, какие модули следует обслуживать.

Если вы выполните команду

 ~$ kubectl get endpoints mongodb-service  

вы должны видеть, что за вашим сервисом нет конечных точек. Причина в том, что ваш сервис неправильно выбирает модули. В настоящее время у вас есть этот селектор:

 selector:  name: mongodb  

но ваши капсулы помечены по-другому:

 labels:  app: mongodb  

Просто изменив значение name на app в манифесте для службы mongodb, следует решить эту проблему.

Еще одна вещь, на которую я хотел обратить ваше внимание, заключается в том, что вы используете статически установленный ip-адрес службы в конфигурации mongodb в flask.

 MONGODB_SETTINGS = {'db': 'mongodb', 'host': '10.97.8.16', 'port': 27017}   

это не очень хороший подход. Лучшим способом сделать это было бы использовать имя службы и позволить kubedns позаботиться о разрешении имени.