我是 Kubernetes 的新手，我是第一次在 Kubernetes 上部署應用程式。我想部署一個 postgreSQL statefulset 和一個簡單的 spring boot pod 副本集。我創建了一個 headless 服務，它將附加到以下 statefulset。
# Headless Service
apiVersion: v1
kind: Service
metadata:
name: ecom-db-h
spec:
ports:
- targetPort: 5432
port: 80
clusterIP: None
selector:
app: ecom-db
---
# PostgreSQL StatefulSet
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: ecomdb-statefulset
labels:
app: ecom-db
spec:
serviceName: ecom-db-h
selector:
matchLabels:
app: postgresql-db
replicas: 2
template:
# Pod Definition
metadata:
labels:
app: postgresql-db
spec:
containers:
- name: db
image: postgres:13
ports:
- name: postgres
containerPort: 5432
# volumeMounts:
# - name: ecom-db
# mountPath: /var/lib/postgresql/data
env:
- name: POSTGRES_DB
value: ecommerce
- name: POSTGRES_USER
value: postgres
- name: POSTGRES_PASSWORD
value: <password>
#volumes:
# - name: ecom-db
# persistentVolumeClaim:
# claimName: ecom-pvc
這是我為 Spring Boot 應用程式 pod 創建的副本集：
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: ecom-server
labels:
app: ecom-server
tier: backend
spec:
# modify replicas according to your case
replicas: 2
selector:
matchLabels:
type: backend
template:
# Pod definition
metadata:
labels:
app: ecom-server
type: backend
spec:
containers:
- name: ecommerce-server
image: <my.private.repo.url>/spring-server:kubernetes-test
imagePullPolicy: Always
imagePullSecrets:
- name: regcred
我使用的是默認命名空間，這里是 application.properties：
spring.datasource.url=jdbc:postgresql://ecom-db-h.default.svc.cluster.local/ecommerce?useSSL=false
spring.datasource.driverClassName=org.postgresql.Driver
spring.datasource.username=postgres
spring.datasource.password=<password>
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.format_sql=true
spring.jpa.hibernate.id.new_generator_mappings=true
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQL95Dialect
但是我的 spring 引導容器總是退出并出現以下錯誤：
Caused by: java.net.UnknownHostException: ecom-db-h.default.svc.cluster.local
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at org.postgresql.core.PGStream.createSocket(PGStream.java:231)
at org.postgresql.core.PGStream.<init>(PGStream.java:95)
at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:98)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:213)
... 136 common frames omitted
這意味著副本集無法找到 headless 服務，或者我的 headless 服務根本沒有連接到 statefulset pod。我是否遺漏了 YAML 檔案中的某些內容？還是我以錯誤的方式使用無頭服務？
更新：
Thanks to @Thomas and @harsh-manvar I understood that the headless service is not meant to connect to the databases. Instead, I should use a normal ClusterIP service. The problem is I did that and I am still getting the same error. Here is my new YAML files :
application.properties modification:
spring.datasource.url=jdbc:postgresql://db-svc.default.svc.cluster.local/ecommerce?useSSL=false
statefulset.yaml modified
# ClusterIP service instead of the headless service
apiVersion: v1
kind: Service
metadata:
name: db-svc
spec:
ports:
- name: pgql
port: 80
targetPort: 5432
protocol: TCP
selector:
app: db
---
# PostgreSQL StatefulSet
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: db-sts
labels:
app: db-sts
spec:
serviceName: db-svc
selector:
matchLabels:
app: db
replicas: 2
template:
# Pod Definition
metadata:
labels:
app: db
spec:
containers:
- name: db
image: postgres:13
ports:
- name: postgres
containerPort: 5432
# volumeMounts:
# - name: ecom-db
# mountPath: /var/lib/postgresql/data
env:
- name: POSTGRES_DB
value: ecommerce
- name: POSTGRES_USER
value: postgres
- name: POSTGRES_PASSWORD
value: mss#123
#volumes:
# - name: ecom-db
# persistentVolumeClaim:
# claimName: ecom-pvc
Here is the new error :
Caused by: java.net.UnknownHostException: db-svc.default.svc.cluster.local
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at org.postgresql.core.PGStream.createSocket(PGStream.java:231)
at org.postgresql.core.PGStream.<init>(PGStream.java:95)
at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:98)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:213)
... 136 common frames omitted
My statefulset pods are running smoothly and the service is created :
NAME READY AGE
statefulset.apps/db-sts 2/2 26m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/db-svc ClusterIP 10.108.39.189 <none> 5432/TCP 26m
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 30m
NAME READY STATUS RESTARTS AGE
db-sts-0 1/1 Running 0 26m
db-sts-1 1/1 Running 0 26m
ecom-server-5jbs2 0/1 CrashLoopBackOff 9 (44s ago) 25m
ecom-server-rtpmg 0/1 CrashLoopBackOff 8 (4m46s ago) 25m
NAME ENDPOINTS AGE
db-svc 10.244.1.48:5432,10.244.2.85:5432 18h
Second Update :
After running an alpine-shell container in a pod to check on the DNS resolving, I performed an "nslookup db-svc.default.svc.cluster.local" and I got this :
nslookup db-svc.default.svc.cluster.local
Server: 10.96.0.10
Address: 10.96.0.10#53
Name: db-svc.default.svc.cluster.local
Address: 10.107.101.52
which means the service does exist and it can be reached from this container. What's strange is when I performed the pgsql command to try to connect to the postgres database server, I got no response at all and the command did not even exit. Here is the error
WARN SqlExceptionHelper - SQL Error: 0, SQLState: 08001
ERROR SqlExceptionHelper - The connection attempt failed.
Caused by: org.postgresql.util.PSQLException: The connection attempt failed.
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:315)
at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:51)
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:225)
at org.postgresql.Driver.makeConnection(Driver.java:465)
at org.postgresql.Driver.connect(Driver.java:264)
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138)
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:358)
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206)
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:477)
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:560)
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115)
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112)
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180)
at org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl.getIsolatedConnection(DdlTransactionIsolatorNonJtaImpl.java:43)
... 122 common frames omitted
Caused by: java.net.SocketTimeoutException: connect timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:607)
at org.postgresql.core.PGStream.createSocket(PGStream.java:231)
at org.postgresql.core.PGStream.<init>(PGStream.java:95)
at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:98)
at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:213)
... 136 common frames omitted
uj5u.com熱心網友回復：
Headless 服務的定義是不提供 DNS 記錄并提供內部負載平衡。
無頭服務可用于查詢端點并分別處理它們。
要解決您的問題，請創建常規服務。
uj5u.com熱心網友回復：
Headless 服務不會為您提供 DNS 記錄，您應該是 ClusterIP 或 NodePort 或 LoadBalancer 中的任何一個
Headless 服務是具有服務 IP 的服務，但它不會進行負載平衡，而是回傳我們關聯的 Pod 的 IP。這允許我們直接與 Pod 互動而不是代理。它就像為 .spec.clusterIP 指定 None 一樣簡單，可以使用或不使用選擇器 - 稍后您將看到一個帶有選擇器的示例。
在以下位置閱讀有關無頭服務的更多資訊：https ://dev.to/kao??skater08/building-a-headless-service-in-kubernetes-3bk8
您可以按照以下 YAML 檔案創建服務型別：ClusterIP
apiVersion: v1
kind: Service
metadata:
name: postgres
spec:
ports:
- name: pgql
port: 5432
targetPort: 5432
protocol: TCP
selector:
app: postgres
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: postgres
spec:
serviceName: "postgres"
replicas: 1
selector:
matchLabels:
app: postgres
template:
metadata:
labels:
app: postgres
spec:
containers:
- name: postgres
image: postgres:9.5
volumeMounts:
- name: postgres-data
mountPath: /var/lib/postgresql/data
subPath: pgdata
env:
- name: POSTGRES_USER
value: root
- name: POSTGRES_PASSWORD
value: password
- name: POSTGRES_DB
value: kong
- name: PGDATA
value: /var/lib/postgresql/data/pgdata
ports:
- containerPort: 5432
terminationGracePeriodSeconds: 60
volumeClaimTemplates:
- metadata:
name: postgres-data
spec:
accessModes:
- "ReadWriteOnce"
resources:
requests:
storage: 10Gi
https://github.com/harsh4870/Keycloack-postgres-kubernetes-deployment/blob/main/postgres.yaml
轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/336935.html
標籤：java 春天 PostgreSQL 弹簧靴 Kubernetes
上一篇：SpringBoot中CommandLineRunner的確切用途是什么
下一篇：春靴和百里香