I am having trouble following along with the instructions to submit a spark job on a kubernetes cluster. I am following the instructions at:

https://spark.apache.org/docs/latest/running-on-kubernetes.html

I have tried to submit the job with:

bin/spark-submit -v --master k8s://http://$MYHOST:8080 --deploy-mode cluster --name spark-pi --class org.apache.spark.examples.SparkPi --conf spark.executor.instances=5 --conf spark.kubernetes.authenticate.driver.serviceAccountName=spark --conf spark.kubernetes.container.image=$MY_IMAGE local:///opt/spark/examples/*jars*/spark-examples_2.11-2.3.0.jar 1000000

I have tried submitting from the host machine and also from a pod inside the kubernetes cluster. When i look at the logs for the driver pod I see the following trace:

2018-05-04 21:00:29 INFO  SparkContext:54 - Added JAR /opt/spark/examples/jars/spark-examples_2.11-2.3.0.jar at spark://spark-pi-d174cee616ff3b5eb4fba1478a3e9ce3-driver-svc.default.svc:7078/jars/spark-examples_2.11-2.3.0.jar with timestamp 1525467629164
2018-05-04 21:00:29 WARN  KubernetesClusterManager:66 - The executor's init-container config map is not specified. Executors will therefore not attempt to fetch remote or submitted dependencies.
2018-05-04 21:00:29 WARN  KubernetesClusterManager:66 - The executor's init-container config map key is not specified. Executors will therefore not attempt to fetch remote or submitted dependencies.
2018-05-04 21:00:29 ERROR SparkContext:91 - Error initializing SparkContext.
org.apache.spark.SparkException: External scheduler cannot be instantiated
    at org.apache.spark.SparkContext$.org$apache$spark$SparkContext$createTaskScheduler(SparkContext.scala:2747)
    at org.apache.spark.SparkContext.<init>(SparkContext.scala:492)
    at org.apache.spark.SparkContext$.getOrCreate(SparkContext.scala:2486)
    at org.apache.spark.sql.SparkSession$Builder$anonfun$7.apply(SparkSession.scala:930)
    at org.apache.spark.sql.SparkSession$Builder$anonfun$7.apply(SparkSession.scala:921)
    at scala.Option.getOrElse(Option.scala:121)
    at org.apache.spark.sql.SparkSession$Builder.getOrCreate(SparkSession.scala:921)
    at org.apache.spark.examples.SparkPi$.main(SparkPi.scala:31)
    at org.apache.spark.examples.SparkPi.main(SparkPi.scala)
Caused by: io.fabric8.kubernetes.client.KubernetesClientException: Operation: [get]  for kind: [Pod]  with name: [spark-pi-d174cee616ff3b5eb4fba1478a3e9ce3-driver]  in namespace: [default]  failed.
    at io.fabric8.kubernetes.client.KubernetesClientException.launderThrowable(KubernetesClientException.java:62)
    at io.fabric8.kubernetes.client.KubernetesClientException.launderThrowable(KubernetesClientException.java:71)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.getMandatory(BaseOperation.java:228)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.get(BaseOperation.java:184)
    at org.apache.spark.scheduler.cluster.k8s.KubernetesClusterSchedulerBackend.<init>(KubernetesClusterSchedulerBackend.scala:70)
    at org.apache.spark.scheduler.cluster.k8s.KubernetesClusterManager.createSchedulerBackend(KubernetesClusterManager.scala:120)
    at org.apache.spark.SparkContext$.org$apache$spark$SparkContext$createTaskScheduler(SparkContext.scala:2741)
    ... 8 more
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1959)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1514)
    at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216)
    at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1026)
    at sun.security.ssl.Handshaker.process_record(Handshaker.java:961)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1072)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1385)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1413)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1397)
    at okhttp3.internal.connection.RealConnection.connectTls(RealConnection.java:281)
    at okhttp3.internal.connection.RealConnection.establishProtocol(RealConnection.java:251)
    at okhttp3.internal.connection.RealConnection.connect(RealConnection.java:151)
    at okhttp3.internal.connection.StreamAllocation.findConnection(StreamAllocation.java:195)
    at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:121)
    at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:100)
    at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
    at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
    at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
    at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:120)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
    at io.fabric8.kubernetes.client.utils.HttpClientUtils$2.intercept(HttpClientUtils.java:93)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
    at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
    at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:185)
    at okhttp3.RealCall.execute(RealCall.java:69)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:377)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:343)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:312)
    at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleGet(OperationSupport.java:295)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.handleGet(BaseOperation.java:783)
    at io.fabric8.kubernetes.client.dsl.base.BaseOperation.getMandatory(BaseOperation.java:217)
    ... 12 more

I am not sure why it is complaining about SSL certificates when the protocol I have specified as part of the spark-submit command is http. I am also not sure which certificate it is complaining about.

Do I need to use the spark.kubernetes.authenticate.submission.caCertFile and spark.kubernetes.authenticate.driver.caCertFile configuration parameters?

Please help! Thanks!