Unable to transfer file to pod if /tmp of pod is read-only

[homerskywalker]

Since changes from 86e740f have been implemented, we have an error when transferring a file to a pod that has /tmp read-only.

Before these changes (fix #4910), it was transferring the file to a directory that is allowed to write, but with the new way to transfer files, it seems it must have write access to /tmp.

To answer the obvious question you will ask as to is it possible to have /tmp writable in our pod, the answer is no, it is impossible.

What we suspect: upload function in PodUpload.java (https://github.com/fabric8io/kubernetes-client/blob/v6.8.1/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/dsl/internal/uploadable/PodUpload.java#L135)

Version with the issue: 6.8.1

Question:
Is there a way (or an option) to have the file being copied directly in the intended directory and not have it copied to /tmp first?
(We need to upgrade version of kubernetes-client, and this is a blocker)

Error message:

Caused by: io.fabric8.kubernetes.client.KubernetesClientException: sh: /tmp/fabric8-a8874cdd-eb99-4f4c-a022-20150120503f.tar: Read-only file system

    at io.fabric8.kubernetes.client.dsl.internal.ExecWebSocketListener.onMessage(ExecWebSocketListener.java:319)
    at io.fabric8.kubernetes.client.okhttp.OkHttpWebSocketImpl$1.onMessage(OkHttpWebSocketImpl.java:110)
    at okhttp3.internal.ws.RealWebSocket.onReadMessage(RealWebSocket.kt:338)
    at okhttp3.internal.ws.WebSocketReader.readMessageFrame(WebSocketReader.kt:247)
    at okhttp3.internal.ws.WebSocketReader.processNextFrame(WebSocketReader.kt:106)
    at okhttp3.internal.ws.RealWebSocket.loopReader(RealWebSocket.kt:293)
    at okhttp3.internal.ws.RealWebSocket$connect$1.onResponse(RealWebSocket.kt:195)
    at okhttp3.internal.connection.RealCall$AsyncCall.run(RealCall.kt:519)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:829)
    Suppressed: java.lang.Throwable: waiting here
            at io.fabric8.kubernetes.client.utils.Utils.waitUntilReady(Utils.java:174)
            at io.fabric8.kubernetes.client.dsl.internal.uploadable.PodUpload.upload(PodUpload.java:101)
            at io.fabric8.kubernetes.client.dsl.internal.uploadable.PodUpload.uploadTar(PodUpload.java:141)
            at io.fabric8.kubernetes.client.dsl.internal.uploadable.PodUpload.upload(PodUpload.java:55)
            at io.fabric8.kubernetes.client.dsl.internal.core.v1.PodOperationsImpl.lambda$upload$4(PodOperationsImpl.java:427)
            at io.fabric8.kubernetes.client.utils.internal.OptionalDependencyWrapper.wrapRunWithOptionalDependency(OptionalDependencyWrapper.java:39)
            at io.fabric8.kubernetes.client.dsl.internal.core.v1.PodOperationsImpl.upload(PodOperationsImpl.java:425)

…

Thank you

[manusa]

I don't think there is one at the moment.

We need to either use the target directory as the temporary directory or make the temp directory configurable.