Is there an alternative to the Jenkins dir() to change to a directory on a Docker container?

Question

Here's my current set-up:

1. Jenkins Master running in Docker on an Ubuntu 18.04 host.
2. A Node running Ubuntu 18.04 with Docker installed.
3. Desired job spins up docker containers on the node which build products in parallel and output to a shared volume.

The issue I'm running into is I'm unable to switch to a directory on the container in which I need to run build commands. The directories exist and can be access using sh() to run various commands for verification. When I try:

dir("/path/on/container") {
    sh "pwd"
}

The console output appears that the dir() function is executed, but there's a failure when tryining to run anything between the curly braces. The failures are (full error text at the end of this post): hudson.remoting.Channel$CallSiteStackTrace: Remote call to DockerHostNode and java.nio.file.AccessDeniedException: /path/on/container.

[DockerTest] Running shell script
+ pwd
/home/jenkins/workspace/DockerTest
[Pipeline] dir
Running in /path/on/container
[Pipeline] {
[Pipeline] echo
Are we in the project dir?
[Pipeline] sh
[Pipeline] }
[Pipeline] // dir
[Pipeline] }
Also:   hudson.remoting.Channel$CallSiteStackTrace: Remote call to DockerHostNode
        at hudson.remoting.Channel.attachCallSiteStackTrace(Channel.java:1741)
        at hudson.remoting.UserRequest$ExceptionResponse.retrieve(UserRequest.java:357)
        at hudson.remoting.Channel.call(Channel.java:955)
        at hudson.FilePath.act(FilePath.java:1070)
        at hudson.FilePath.act(FilePath.java:1059)
        at hudson.FilePath.mkdirs(FilePath.java:1244)
        at org.jenkinsci.plugins.durabletask.FileMonitoringTask$FileMonitoringController.<init>(FileMonitoringTask.java:171)
        at org.jenkinsci.plugins.durabletask.BourneShellScript$ShellController.<init>(BourneShellScript.java:197)
        at org.jenkinsci.plugins.durabletask.BourneShellScript$ShellController.<init>(BourneShellScript.java:189)
        at org.jenkinsci.plugins.durabletask.BourneShellScript.launchWithCookie(BourneShellScript.java:110)
        at org.jenkinsci.plugins.durabletask.FileMonitoringTask.launch(FileMonitoringTask.java:98)
        at org.jenkinsci.plugins.workflow.steps.durable_task.DurableTaskStep$Execution.start(DurableTaskStep.java:264)
        at org.jenkinsci.plugins.workflow.cps.DSL.invokeStep(DSL.java:270)
        at org.jenkinsci.plugins.workflow.cps.DSL.invokeMethod(DSL.java:180)
        at org.jenkinsci.plugins.workflow.cps.CpsScript.invokeMethod(CpsScript.java:122)
        at sun.reflect.GeneratedMethodAccessor263.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
        at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1213)
        at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1022)
        at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:42)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
        at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:157)
        at org.kohsuke.groovy.sandbox.GroovyInterceptor.onMethodCall(GroovyInterceptor.java:23)
        at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:155)
        at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:155)
        at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:159)
        at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:129)
        at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:129)
        at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.methodCall(SandboxInvoker.java:17)
        at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:57)
        at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:109)
        at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixArg(FunctionCallBlock.java:82)
        at sun.reflect.GeneratedMethodAccessor157.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
        at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
        at com.cloudbees.groovy.cps.Next.step(Next.java:83)
        at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:174)
        at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:163)
        at org.codehaus.groovy.runtime.GroovyCategorySupport$ThreadCategoryInfo.use(GroovyCategorySupport.java:129)
        at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:268)
        at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:163)
        at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$101(SandboxContinuable.java:34)
        at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.lambda$run0$0(SandboxContinuable.java:59)
        at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox.runInSandbox(GroovySandbox.java:108)
        at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:58)
        at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:182)
        at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:332)
        at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$200(CpsThreadGroup.java:83)
        at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:244)
        at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:232)
        at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:64)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:131)
        at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
        at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
java.nio.file.AccessDeniedException: /path/on/container
    at sun.nio.fs.UnixException.translateToIOException(UnixException.java:84)
    at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
    at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
    at sun.nio.fs.UnixFileSystemProvider.createDirectory(UnixFileSystemProvider.java:384)
    at java.nio.file.Files.createDirectory(Files.java:674)
    at java.nio.file.Files.createAndCheckIsDirectory(Files.java:781)
    at java.nio.file.Files.createDirectories(Files.java:767)
    at hudson.FilePath.mkdirs(FilePath.java:3271)
    at hudson.FilePath.access$1300(FilePath.java:211)
    at hudson.FilePath$Mkdirs.invoke(FilePath.java:1252)
    at hudson.FilePath$Mkdirs.invoke(FilePath.java:1248)
    at hudson.FilePath$FileCallableWrapper.call(FilePath.java:3084)
    at hudson.remoting.UserRequest.perform(UserRequest.java:212)
    at hudson.remoting.UserRequest.perform(UserRequest.java:54)
    at hudson.remoting.Request$2.run(Request.java:369)
    at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

The path on the container is a docker volume and the containers are all running with -u root, so I'm not entirely sure why I'm getting an AccessDenied. The only thing I can think is that, because of the previous "Remote call to DockerHostNode", it's trying to access /path/on/container which doesn't exist of the node itself. Any ideads? Here's the full error text:

Answer 1

I could not achieve changing the working directory using the suggestion by Vishwas, although I did try creating a Jenkins user inside the container with the same uid as the host. It just didn't work for me. I did however, realize that I didn't actually need to change the directory on the container because the workspace was already in the container.

I'm using the Docker Plugin from CloudBees. After reading their documentation, I realized the workstation folder I thought was on the host machine, was actually in the container. Part of the documentation stated:

The above is a complete Pipeline script. inside will:

1. Automatically grab an agent and a workspace (no extra node block is required).
2. Pull the requested image to the Docker server (if not already cached).
3. Start a container running that image.
4. Mount the Jenkins workspace as a "volume" inside the container, using the same file path.

After seeing item number four, I ran docker container inspect <containerID> and I saw the workspace /home/jenkins/workspace was actually a volume mount that was mapped to the /home/jenkins/workspace on the Docker host machine as well. Using this as my workspace, I was able to build the various applications within the container and then moved the results to a second volume used for application collection later in the pipeline. It's not an exact answer to my original question, but it works!

Answer 2

If your master is running as Jenkins user, you should make a user in the docker image which you use as to create your node and do the key exchange. For example jenkinsuser with same UID needs to exist on both master and node docker container.