java - Spring Kafka SSL setup in Spring boot application.yml

Question

I am trying to setup a Spring Boot Application with a Kafka Client to use SSL. I have my keystore.jks and truststore.jks stored on a filesystem(on a docker container) because of this: https://github.com/spring-projects/spring-kafka/issues/710

Here is my application.yml:

spring:
  kafka:
      ssl:
        key-password: pass
        keystore-location: /tmp/kafka.client.keystore.jks
        keystore-password: pass
        truststore-location: /tmp/kafka.client.truststore.jks
        truststore-password: pass

But when I start the application ( in a docker container) it says:

Caused by: java.lang.IllegalStateException: Resource 'class path resource [tmp/kafka.client.keystore.jks]' must be on a file system
[..]
Caused by: java.io.FileNotFoundException: class path resource [tmp/kafka.client.keystore.jks] cannot be resolved to URL because it does not exist

I checked on the container and the .jks are there in /tmp .

I cannot understand how to pass .jks to spring boot.

UPDATE 06/07/2018

This is my dockerfile

FROM openjdk:8-jdk-alpine
VOLUME /tmp
COPY ssl/kafka.client.keystore.jks /tmp
COPY ssl/kafka.client.truststore.jks /tmp
ARG JAR_FILE
ADD ${JAR_FILE} app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

Answer 1

If anyone is still looking at this, try prepending file:// to the file path:

truststorelocation: "file:///tmp/kafka.client.keystore.jks"

The error is complaining about the lack of a URL - adding a protocol (file://) makes the path a URL (speaking very basically)