Step 12/12 : CMD bundle exec rake db:migrate && bundle exec rails s
---> Using cache
---> b7c2febdf592
Successfully built b7c2febdf592
Successfully tagged app:b2279a4

Caused by: com.github.dockerjava.api.exception.DockerClientException: Could not build image: null
        at com.github.dockerjava.core.command.BuildImageResultCallback.getImageId(BuildImageResultCallback.java:71)
        at com.github.dockerjava.core.command.BuildImageResultCallback.awaitImageId(BuildImageResultCallback.java:48)
        at java_lang_reflect_Method$invoke.call(Unknown Source)
        at java_lang_reflect_Method$invoke.call(Unknown Source)
        at com.bmuschko.gradle.docker.utils.DockerThreadContextClassLoader$_createPrintStreamProxyCallback_closure12.doCall(DockerThreadContextClassLoader.groovy:577)
        at com.sun.proxy.$Proxy160.invoke(Unknown Source)
        at com.github.dockerjava.core.command.BuildImageResultCallback$$EnhancerByCGLIB$$994b76df.awaitImageId(<generated>)
        at com.github.dockerjava.core.command.BuildImageResultCallback$$EnhancerByCGLIB$$994b76df$awaitImageId.call(Unknown Source)
        at com.github.dockerjava.core.command.BuildImageResultCallback$$EnhancerByCGLIB$$48a3fefd$awaitImageId.call(Unknown Source)
        at com.bmuschko.gradle.docker.tasks.image.DockerBuildImage.runRemoteCommand(DockerBuildImage.groovy:127)
        at com.bmuschko.gradle.docker.tasks.AbstractDockerRemoteApiTask$_runReactiveStream_closure1.doCall(AbstractDockerRemoteApiTask.groovy:57)
        at com.bmuschko.gradle.docker.utils.DockerThreadContextClassLoader.withClasspath(DockerThreadContextClassLoader.groovy:54)
        at com.bmuschko.gradle.docker.utils.ThreadContextClassLoader$withClasspath.call(Unknown Source)
        at com.bmuschko.gradle.docker.tasks.AbstractDockerRemoteApiTask.runInDockerClassPath(AbstractDockerRemoteApiTask.groovy:62)
        at com.bmuschko.gradle.docker.tasks.AbstractDockerRemoteApiTask$runInDockerClassPath.callCurrent(Unknown Source)
        at com.bmuschko.gradle.docker.tasks.AbstractDockerRemoteApiTask.runReactiveStream(AbstractDockerRemoteApiTask.groovy:56)
        at com.bmuschko.gradle.docker.tasks.AbstractReactiveStreamsTask.start(AbstractReactiveStreamsTask.groovy:50)
        at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
        at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.doExecute(DefaultTaskClassInfoStore.java:141)
        at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:134)
        at org.gradle.api.internal.project.taskfactory.DefaultTaskClassInfoStore$StandardTaskAction.execute(DefaultTaskClassInfoStore.java:123)
        at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:632)
        at org.gradle.api.internal.AbstractTask$TaskActionWrapper.execute(AbstractTask.java:615)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:95)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:76)
        ... 70 more