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There is error message KafkaAdminClient when try to connect to local kafka broker deployed on local k8s

I'm trying to deploy kafka on local k8s, then I need to connect to it by application and using offset explorer
so, using kubectl I created zookeeper service and deployment using this yml file
apiVersion: v1
kind: Service
metadata:
labels:
app: zookeeper-service
name: zookeeper-service
spec:
type: NodePort
ports:
- name: zookeeper-port
port: 2181
nodePort: 30181
targetPort: 2181
selector:
app: zookeeper
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: zookeeper
name: zookeeper
spec:
replicas: 1
selector:
matchLabels:
app: zookeeper
template:
metadata:
labels:
app: zookeeper
spec:
containers:
- image: wurstmeister/zookeeper
imagePullPolicy: IfNotPresent
name: zookeeper
ports:
- containerPort: 2181
Then, I created kafka service and deployment using this yml
apiVersion: v1
kind: Service
metadata:
labels:
app: kafka-service
name: kafka-service
spec:
type: NodePort
ports:
- name: kafka-port
port: 9092
nodePort: 30182
targetPort: 9092
selector:
app: kafka-broker
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: kafka-broker
name: kafka-broker
spec:
replicas: 1
selector:
matchLabels:
app: kafka-broker
template:
metadata:
labels:
app: kafka-broker
spec:
hostname: kafka-broker
containers:
- env:
- name: KAFKA_BROKER_ID
value: "1"
- name: KAFKA_ZOOKEEPER_CONNECT
value: 10.97.29.226:2181
- name: KAFKA_LISTENERS
value: PLAINTEXT://:9092
- name: KAFKA_ADVERTISED_LISTENERS
value: PLAINTEXT://kafka-broker:9092
image: wurstmeister/kafka
imagePullPolicy: IfNotPresent
name: kafka-broker
ports:
- containerPort: 9092
And both services and deployment created and running
but, when I try to connect to this kafka using offset key tool, there is error connection.
If I define only this page , there is success connection, but error when try to view kafka topic
error message
then I add borker description on advanced page like this
But there is error message Error connecting to the cluster, Fail to create new KafkaAdminClient

Spring Boot Microservices cannot run on Kubernetes (java.net.SocketTimeoutException: connect timed out)

I have a problem about running Spring Boot Microservices on Kubernetes. After I installed minikube, I started it and open its dashboard.
Here is the commands to open dashboards.
1 ) minikube start
2 ) minikube dashboard
Next, I run all services through this command.
kubectl apply -f k8s
After waiting for a certain amount of time, I got this issue shown below.
15:22:37.395 [main] ERROR org.springframework.boot.SpringApplication - Application run failed
org.springframework.cloud.config.client.ConfigClientFailFastException: Could not locate PropertySource and the resource is not optional, failing
at org.springframework.cloud.config.client.ConfigServerConfigDataLoader.doLoad(ConfigServerConfigDataLoader.java:197)
at org.springframework.cloud.config.client.ConfigServerConfigDataLoader.load(ConfigServerConfigDataLoader.java:102)
at org.springframework.cloud.config.client.ConfigServerConfigDataLoader.load(ConfigServerConfigDataLoader.java:61)
at org.springframework.boot.context.config.ConfigDataLoaders.load(ConfigDataLoaders.java:107)
at org.springframework.boot.context.config.ConfigDataImporter.load(ConfigDataImporter.java:128)
at org.springframework.boot.context.config.ConfigDataImporter.resolveAndLoad(ConfigDataImporter.java:86)
at org.springframework.boot.context.config.ConfigDataEnvironmentContributors.withProcessedImports(ConfigDataEnvironmentContributors.java:116)
at org.springframework.boot.context.config.ConfigDataEnvironment.processWithProfiles(ConfigDataEnvironment.java:311)
at org.springframework.boot.context.config.ConfigDataEnvironment.processAndApply(ConfigDataEnvironment.java:232)
at org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessor.postProcessEnvironment(ConfigDataEnvironmentPostProcessor.java:102)
at org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessor.postProcessEnvironment(ConfigDataEnvironmentPostProcessor.java:94)
at org.springframework.boot.env.EnvironmentPostProcessorApplicationListener.onApplicationEnvironmentPreparedEvent(EnvironmentPostProcessorApplicationListener.java:102)
at org.springframework.boot.env.EnvironmentPostProcessorApplicationListener.onApplicationEvent(EnvironmentPostProcessorApplicationListener.java:87)
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:131)
at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:85)
at org.springframework.boot.SpringApplicationRunListeners.lambda$environmentPrepared$2(SpringApplicationRunListeners.java:66)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:120)
at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:114)
at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:65)
at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:344)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:302)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295)
at com.microservice.orderservice.OrderServiceApplication.main(OrderServiceApplication.java:15)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:65)
Caused by: org.springframework.web.client.ResourceAccessException: I/O error on GET request for "http://config-server-svc:9296/ORDER-SERVICE/default": connect timed out; nested exception is java.net.SocketTimeoutException: connect timed out
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:785)
at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:711)
at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:602)
at org.springframework.cloud.config.client.ConfigServerConfigDataLoader.getRemoteEnvironment(ConfigServerConfigDataLoader.java:303)
at org.springframework.cloud.config.client.ConfigServerConfigDataLoader.doLoad(ConfigServerConfigDataLoader.java:118)
... 35 common frames omitted
Caused by: java.net.SocketTimeoutException: connect timed out
at java.base/java.net.PlainSocketImpl.socketConnect(Native Method)
at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:412)
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:255)
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:237)
at java.base/java.net.Socket.connect(Socket.java:609)
at java.base/sun.net.NetworkClient.doConnect(NetworkClient.java:177)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:508)
at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:603)
at java.base/sun.net.www.http.HttpClient.<init>(HttpClient.java:276)
at java.base/sun.net.www.http.HttpClient.New(HttpClient.java:375)
at java.base/sun.net.www.http.HttpClient.New(HttpClient.java:396)
at java.base/sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1253)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1187)
at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1081)
at java.base/sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:1015)
at org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal(SimpleBufferingClientHttpRequest.java:76)
at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48)
at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:66)
at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:776)
... 39 common frames omitted
Here is my deployment.yaml file shown below.
apiVersion: apps/v1
kind: Deployment
metadata:
name: auth-service-app
spec:
selector:
matchLabels:
app: auth-service-app
template:
metadata:
labels:
app: auth-service-app
spec:
containers:
- name: auth-service-app
image: noyandocker/authservice
imagePullPolicy: IfNotPresent
ports:
- containerPort: 7777
env:
- name: CONFIG_SERVER_URL
valueFrom:
configMapKeyRef:
name: config-cm
key: config_url
- name: EUREKA_SERVER_ADDRESS
valueFrom:
configMapKeyRef:
name: eureka-cm
key: eureka_service_address
- name: DB_HOST
valueFrom:
configMapKeyRef:
name: mysql-cm
key: hostname
---
apiVersion: v1
kind: Service
metadata:
name: auth-service-svc
spec:
selector:
app: auth-service-app
ports:
- port: 80
targetPort: 7777
Here is the configmap yaml file shown below
apiVersion: v1
kind: ConfigMap
metadata:
name: config-cm
data:
config_url: "config-server-svc"
---
apiVersion: v1
kind: ConfigMap
metadata:
name: eureka-cm
data:
eureka_service_address: "http://eureka-0.eureka:8761/eureka"
---
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql-cm
data:
hostname: "mysql-0.mysql"
Here is the config server yaml file shown below
apiVersion: apps/v1
kind: Deployment
metadata:
name: config-server-app
spec:
selector:
matchLabels:
app: config-server-app
template:
metadata:
labels:
app: config-server-app
spec:
containers:
- name: config-server-app
image: noyandocker/configserver
imagePullPolicy: IfNotPresent
ports:
- containerPort: 9296
readinessProbe:
httpGet:
path: /actuator/health
port: 9296
initialDelaySeconds: 20
timeoutSeconds: 10
periodSeconds: 3
failureThreshold: 10
livenessProbe:
httpGet:
path: /actuator/health
port: 9296
initialDelaySeconds: 30
timeoutSeconds: 2
periodSeconds: 8
failureThreshold: 10
env:
- name: EUREKA_SERVER_ADDRESS
valueFrom:
configMapKeyRef:
name: eureka-cm
key: eureka_service_address
---
apiVersion: v1
kind: Service
metadata:
name: config-server-svc
spec:
selector:
app: config-server-app
ports:
- port: 80
targetPort: 9296
I thought all the services will start simultaneously. Config Server is the Dependent Service for all other Serivces like auth service and this Auth service should not start until Config Server service is up and running.
Editted
I added this code snippets shown below in cloud_gateway_deployment.yaml file but it didn't work.
initContainers:
- name: init-configserver
image: noyandocker/configserver
command: [ 'sh', '-c', "until nslookup config-server-svc.$(cat /var/run/secrets/kubernetes.io/serviceaccount/namespace).svc.cluster.local; do echo waiting for config server; sleep 2; done" ]
How can I do that?
Here is my repo : Link
Here is my docker hub : Link
Here is git backend system : Link

If you have a dependency you need other services to wait on, I'd suggest implementing an init container, which will allow you to program the k8s deployment to wait for some dependency to exist or finish starting up. We've done something similar for a database, since many of our spring boot services in k8s need a database to be up.
https://kubernetes.io/docs/concepts/workloads/pods/init-containers/
Also, make sure you familiarize yourself with the way the k8s network routing works, and DNS for other pods, which uses their name.
https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/

K8s Spring Application cannot connect to Mysql DB

I wanted to try and deploy my spring boot application on kubernetes. I setted up a test environment with microk8s (dns,storage,ingress enabled) which consists of a pod running the application itself and a pod with the MySQL database. Each pod has its own service and is running on the same default namespace. The yaml files can be seen bellow:
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp-deployment
spec:
replicas: 1
selector:
matchLabels:
app: myapp
template:
metadata:
labels:
app: myapp
spec:
containers:
- name: test-app
image: myImage
ports:
- containerPort: 8080
imagePullPolicy: Always
env:
- name: SPRING_APPLICATION_JSON
valueFrom:
configMapKeyRef:
name: spring-config
key: app-config.json
Application Service:
apiVersion: v1
kind: Service
metadata:
name: myapp-service
spec:
selector:
app: myapp
ports:
- port: 8080
targetPort: 8080
Mysql Deployment:
apiVersion: apps/v1
kind: Deployment
metadata:
name: mysql-server
labels:
# app: mysql
app: mysql
spec:
replicas: 1
selector:
matchLabels:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
volumes:
- name: mysql-persistent-volume-storage
persistentVolumeClaim:
claimName: mysql-pvc-claim
containers:
- name: mysql
image: mysql
volumeMounts:
- name: mysql-persistent-volume-storage
mountPath: /var/lib/mysql
subPath: mysql-server
env:
- name: MYSQL_ROOT_PASSWORD
value: pass_root
- name: MYSQL_USER
value: user
- name: MYSQL_PASSWORD
value: pass
- name: MYSQL_DATABASE
value: test
ports:
- containerPort: 3306
Mysql Service:
apiVersion: v1
kind: Service
metadata:
name: db-service
spec:
selector:
app: mysql
ports:
- port: 3306
targetPort: 3306
For some reason my application can't use the database. It throws this error:
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.25.jar!/:8.0.25]
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-java-8.0.25.jar!/:8.0.25]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:833) ~[mysql-connector-java-8.0.25.jar!/:8.0.25]
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:453) ~[mysql-connector-java-8.0.25.jar!/:8.0.25]
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246) ~[mysql-connector-java-8.0.25.jar!/:8.0.25]
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198) ~[mysql-connector-java-8.0.25.jar!/:8.0.25]
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:121) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:364) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:476) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) ~[HikariCP-4.0.3.jar!/:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-4.0.3.jar!/:na]
.......
The application.yml:
db:
datasource:
url: jdbc:mysql://ip/test
user: user
password: pass
---
spring:
datasource:
url: ${db.datasource.url}
username: ${db.datasource.user}
password: ${db.datasource.password}
driver-class-name: com.mysql.cj.jdbc.Driver
jpa:
database-platform: org.hibernate.dialect.MySQLDialect
mvc:
view:
suffix: .html
thymeleaf:
cache: false
allowPublicKeyRetrieval: true
hibernate:
show_sql: true
logging:
level:
org:
hibernate:
SQL: debug
I tried accessing the service from another pod on the namespace running mysql, since it has the mysql-client pre installed, and from the host. Both had access to database. I also tring ping on the pod running the application. It found the service withoyt any problem.
Then I tried using NodePort instead of ClusterIP. Nothing changed.
I made sure the credentials are correct.
Finally, I tried removing and adding the port in the application.yml.
I am completely stuck and I have no idea what's the problem. Any help would be appreciated.

I spot two problems in your configuration: The username/password in your mysql deployment does not match the values in your application.yaml.
The other one is that you use a property that spring boot does not use by default and I assume you have no special logic to handle that: "spring.data.url" should be "spring.datasource.url".
Note that it should be "spring.datasource.username" , not "user" as well.
Referring to your 'db' section in the YAML: In general I would not recommend to have a separate section for the database credentials and reference it using variables as well.

Spring Boot Docker Image not able to connect to external Redis Cluster when run in Kubernetes Pod

I have created a Docker Image. It is not able to connect to external Redis Cluster when I am deploying the image to the Kubernetes cluster. But it is running fine in Docker container.
The following are my configuration yaml.
deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: testappname
name: testappname
spec:
replicas: 1
selector:
matchLabels:
app: testappname
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: testappname
spec:
containers:
- image: imageName:latest
name: testappname
resources: {}
status: {}
service.yaml
apiVersion: v1
kind: Service
metadata:
creationTimestamp: null
labels:
app: testappname
name: testappname
spec:
ports:
- name: 8089-8089
port: 8089
protocol: TCP
targetPort: 8089
selector:
app: testappname
type: ClusterIP
status:
loadBalancer: {}

Connect Refused Kubernetes Service Discovery Using Spring Boot

I am trying to setup up a simple discovery using spring-boot-kubernetes but every time getting connection refused when trying to excess a service by service name.
I have included:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-kubernetes</artifactId>
</dependency>
And added the #EnableDiscoveryClient annotation.
Below is the deployment.yml of the service that I am trying to call from the other service via name.
kind: Service
apiVersion: v1
metadata:
name: sample-rest
spec:
selector:
app: sample-rest
ports:
- protocol: TCP
port: 8771
targetPort: 8771
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app.kubernetes.io/name: sample-rest
name: sample-rest
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: sample-rest
template:
metadata:
labels:
app.kubernetes.io/name: sample-rest
spec:
containers:
- name: sample-rest
image: kryptonian/sample-rest:1.0
ports:
- containerPort: 8771
Below is the deployment.yml for the discovery service inside which I am trying to call the above service via name.
kind: Service
apiVersion: v1
metadata:
name: sample-discovery
spec:
selector:
app: sample-discovery
ports:
- protocol: TCP
port: 8772
targetPort: 8772
type: NodePort
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app.kubernetes.io/name: sample-discovery
name: sample-discovery
spec:
replicas: 1
selector:
matchLabels:
app.kubernetes.io/name: sample-discovery
template:
metadata:
labels:
app.kubernetes.io/name: sample-discovery
spec:
containers:
- name: sample-discovery
image: kryptonian/discovery-sample:1.0
ports:
- containerPort: 8772
Code to call the service :
#GetMapping("/test")
public String getHelloMessage() {
RestTemplate restTemplate = new RestTemplate();
String url = "http://sample-rest:8771/sample";
ResponseEntity<String> result = restTemplate.getForEntity(url, String.class);
return result.getBody();
}
Everytime i am trying to call the endpoint below error comes on the logs and ui.
2020-04-13 16:08:04.187 ERROR 1 --- [nio-8772-exec-5] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.client.ResourceAccessException: I/O error on GET request for "http://sample-rest:8771/sample": Connection refused (Connection refused); nested exception is java.net.ConnectException: Connection refused (Connection refused)] with root cause
java.net.ConnectException: Connection refused (Connection refused)
at java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:1.8.0_212]
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_212]
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_212]
Output of kubectl describe svc sample-rest
Name: sample-rest
Namespace: default
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"name":"sample-rest","namespace":"default"},"spec":{"ports":[{"port":8771...
Selector: app=sample-rest
Type: NodePort
IP: 10.35.250.117
Port: <unset> 8771/TCP
TargetPort: 8771/TCP
NodePort: <unset> 31406/TCP
Endpoints: <none>
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>

The issue here is endpoints is empty for service sample-rest.You should check that the spec.selector field of your Service actually selects for metadata.labels values on your Pods. There is app: sample-rest as spec.selector but the pod label have app.kubernetes.io/name: sample-rest which is not matching.
https://kubernetes.io/docs/tasks/debug-application-cluster/debug-service/#does-the-service-have-any-endpoints
Also you can try connecting to POD IP directly bypassing service to isolate if this is a problem with the service.