<p>I have a spring boot service which I want to connect to a mongodb in Kubernetes. So far, I have built the docker image of the app and created a Kubernetes deployment, specifying both the images for the app and mongodb in the same deployment YAML file. Also, I have created a service YAML for the app and it works fine.</p>
<p>deployment.yml</p>
<pre><code>apiVersion: apps/v1
kind: Deployment
metadata:
  name: springbootmongodb
  labels:
    app: springbootmongodb
spec:
  replicas: 1
  selector:
    matchLabels:
      app: springbootmongodb
  template:
    metadata:
      labels:
        app: springbootmongodb
    spec:
      containers:
      - name: springbootmongodb
        image: mytest/springbootmongodb
      - name: mongo
        image: mongo
</code></pre>
<p>--service.yaml</p>
<pre><code>apiVersion: v1
kind: Service
metadata:
  name: springbootmongodb
  labels:
    app: springbootmongodb
spec:
  type: ClusterIP
  ports:
  - name: 8080-8080
    port: 8080
    targetPort: 8080
    protocol: TCP
  selector:
    app: springbootmongodb
</code></pre>
<p>port forward command:</p>
<pre><code>kubectl port-forward svc/springbootmongodb 8080:8080
</code></pre>
<p>Everything works with the above config.</p>
<p>Now, I want to create separate deployments for the app and created two deployments and service YAMLs, but it doesn't work. Can someone please help me?</p>
<p>app-deployment.yaml</p>
<pre><code>apiVersion: apps/v1
kind: Deployment
metadata:
  name: springbootmongodb
  labels:
    app: springbootmongodb
spec:
  replicas: 1
  selector:
    matchLabels:
      app: springbootmongodb
  template:
    metadata:
      labels:
        app: springbootmongodb
    spec:
      containers:
      - name: springbootmongodb
        image: mytest/springbootmongodb
</code></pre>
<p>mongo-deployment.yml</p>
<pre><code>apiVersion: apps/v1
kind: Deployment
metadata:
  name: mongodb
  labels:
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mongo
  template:
    metadata:
      labels:
        app: mongo
    spec:
      containers:
        - name: mongo
          image: mongo
          ports:
            - containerPort: 27017
</code></pre>
<p>appservice.yml</p>
<pre><code>apiVersion: v1
kind: Service
metadata:
  name: springbootmongodb
  labels:
    app: springbootmongodb
spec:
  type: NodePort
  ports:
  - name: 8080-8080
    port: 8080
    targetPort: 8080
    protocol: TCP
  selector:
    app: springbootmongodb
</code></pre>
<p>mongoservice.yml</p>
<pre><code>apiVersion: v1
kind: Service
metadata:
  name: mongodb
  labels:
    app: mongo
spec:
  type: ClusterIP
  ports:
    - port: 27017
      targetPort: 27017
      protocol: TCP
  selector:
    app: mongo
</code></pre>
<p>I see all created objects:</p>
<p>kubectl get pods
NAME                                 READY   STATUS    RESTARTS   AGE
mongodb-686dd5cb7f-dr9hq             1/1     Running   0          3m12s
springbootmongodb-7ccbc488fb-vtgw5   1/1     Running   0          115s</p>
<p>kubectl get all</p>
<pre><code>NAME                                     READY   STATUS    RESTARTS   AGE
pod/mongodb-686dd5cb7f-dr9hq             1/1     Running   0          3m16s
pod/springbootmongodb-7ccbc488fb-vtgw5   1/1     Running   0          119s

NAME                        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
service/kubernetes          ClusterIP   10.96.0.1       &lt;none&gt;        443/TCP          59d
service/mongodb             ClusterIP   10.111.83.192   &lt;none&gt;        27017/TCP        2m35s
service/springbootmongodb   NodePort    10.103.18.137   &lt;none&gt;        8080:31015/TCP   8s

NAME                                READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/mongodb             1/1     1            1           3m16s
deployment.apps/springbootmongodb   1/1     1            1           119s

NAME                                           DESIRED   CURRENT   READY   AGE
replicaset.apps/mongodb-686dd5cb7f             1         1         1       3m16s
replicaset.apps/springbootmongodb-7ccbc488fb   1         1         1       119s
</code></pre>
<p>Error logs for service:</p>
<pre><code>2020-08-06 23:19:01.526  INFO 1 --- [nio-8080-exec-8] org.mongodb.driver.cluster               : Cluster description not yet available. Waiting for 30000 ms before timing out
2020-08-06 23:19:07.048 ERROR 1 --- [nio-8080-exec-7] 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.dao.DataAccessResourceFailureException: Timed out after 30000 ms while waiting to connect. Client view of cluster state is {type=UNKNOWN, servers=[{address=localhost:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.ConnectException: Connection refused (Connection refused)}}]; nested exception is com.mongodb.MongoTimeoutException: Timed out after 30000 ms while waiting to connect. Client view of cluster state is {type=UNKNOWN, servers=[{address=localhost:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.ConnectException: Connection refused (Connection refused)}}]] with root cause

com.mongodb.MongoTimeoutException: Timed out after 30000 ms while waiting to connect. Client view of cluster state is {type=UNKNOWN, servers=[{address=localhost:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {java.net.ConnectException: Connection refused (Connection refused)}}]
        at com.mongodb.internal.connection.BaseCluster.getDescription(BaseCluster.java:179) ~[mongodb-driver-core-3.8.2.jar!/:na]
        at com.mongodb.internal.connection.SingleServerCluster.getDescription(SingleServerCluster.java:41) ~[mongodb-driver-core-3.8.2.jar!/:na]
        at com.mongodb.client.internal.MongoClientDelegate.getConnectedClusterDescription(MongoClientDelegate.java:136) ~[mongodb-driver-3.8.2.jar!/:na]
        at com.mongodb.client.internal.MongoClientDelegate.createClientSession(MongoClientDelegate.java:94) ~[mongodb-driver-3.8.2.jar!/:na]
        at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.getClientSession(MongoClientDelegate.java:249) ~[mongodb-driver-3.8.2.jar!/:na]
        at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.execute(MongoClientDelegate.java:172) ~[mongodb-driver-3.8.2.jar!/:na]
        at com.mongodb.client.internal.MongoIterableImpl.execute(MongoIterableImpl.java:132) ~[mongodb-driver-3.8.2.jar!/:na]
        at com.mongodb.client.internal.MongoIterableImpl.iterator(MongoIterableImpl.java:86) ~[mongodb-driver-3.8.2.jar!/:na]
        at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:2643) ~[spring-data-mongodb-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2380) ~[spring-data-mongodb-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:2363) ~[spring-data-mongodb-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:820) ~[spring-data-mongodb-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findAll(SimpleMongoRepository.java:360) ~[spring-data-mongodb-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findAll(SimpleMongoRepository.java:194) ~[spring-data-mongodb-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.findAll(SimpleMongoRepository.java:51) ~[spring-data-mongodb-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_212]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_212]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_212]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_212]
        at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:359) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:200) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:644) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.2.RELEASE.jar!/:5.1.2.RELEASE]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:608) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.2.RELEASE.jar!/:5.1.2.RELEASE]
        at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.2.RELEASE.jar!/:5.1.2.RELEASE]
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) ~[spring-aop-5.1.2.RELEASE.jar!/:5.1.2.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.1.2.RELEASE.jar!/:5.1.2.RELEASE]
        at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61) ~[spring-data-commons-2.1.2.RELEASE.jar!/:2.1.2.RELEASE]
</code></pre>

<p>It looks like you need to change the config of your Springboot app to use the mongodb endpoint: <code>mongodb:27017</code> rather than <code>localhost:27017</code>❓🤔. Since mongo is not running on the same container/pod anymore.</p>
<p><a href="https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-mongodb" rel="noreferrer">In the <code>application.properties</code> file something like this</a>:</p>
<pre><code>spring.data.mongodb.uri=mongodb://mongodb:27017/&lt;dbname&gt;
</code></pre>
<p>✌️</p>
