| Using jenkins/slave:latest remoting image in Docker Slaves plugin, our builds stopped working a few days ago with a permissions error when initializing the JAR Cache location. This is the relevant console output for the build:
[Pipeline] dockerNode
Start Docker container to host the build
Unable to find image 'jenkins/slave:latest' locally
latest: Pulling from jenkins/slave
54f7e8ac135a: Already exists
d6341e30912f: Already exists
087a57faf949: Already exists
5d71636fb824: Already exists
9da6b28682cf: Already exists
203f1094a1e2: Already exists
ee38d9f85cf6: Already exists
7f692fae02b6: Already exists
eaa976dc543c: Already exists
173a06ff64cc: Pulling fs layer
28fc185aee23: Pulling fs layer
e02013eddffd: Pulling fs layer
cc49fe331e2e: Pulling fs layer
cc49fe331e2e: Waiting
173a06ff64cc: Verifying Checksum
173a06ff64cc: Download complete
28fc185aee23: Verifying Checksum
28fc185aee23: Download complete
e02013eddffd: Verifying Checksum
e02013eddffd: Download complete
173a06ff64cc: Pull complete
28fc185aee23: Pull complete
e02013eddffd: Pull complete
cc49fe331e2e: Verifying Checksum
cc49fe331e2e: Download complete
cc49fe331e2e: Pull complete
Digest: sha256:5683f906bab2e28abe332619bcec340a4da8553f10c34bbcbe6b555d32f76196
Status: Downloaded newer image for jenkins/slave:latest
[12/28/18 01:02:51] Launching agent
$ docker start --interactive --attach 56be9bbd2bba60384bb02e9ba11a2a8cc4bbb954620b4dcc9a03ca9f3399b315
Exception in thread "main" java.io.IOException: Failed to initialize the default JAR Cache location
at hudson.remoting.JarCache.getDefault(JarCache.java:41)
at hudson.remoting.ChannelBuilder.withJarCacheOrDefault(ChannelBuilder.java:220)
at hudson.remoting.Launcher.main(Launcher.java:736)
at hudson.remoting.Launcher.runWithStdinStdout(Launcher.java:691)
at hudson.remoting.Launcher.run(Launcher.java:373)
at hudson.remoting.Launcher.main(Launcher.java:283)
Caused by: java.lang.IllegalArgumentException: Root directory not writable: ?/.jenkins/cache/jars
at hudson.remoting.FileSystemJarCache.<init>(FileSystemJarCache.java:62)
at hudson.remoting.JarCache.getDefault(JarCache.java:39)
... 5 more
Caused by: java.nio.file.AccessDeniedException: /home/jenkins/?
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.remoting.Util.mkdirs(Util.java:231)
at hudson.remoting.FileSystemJarCache.<init>(FileSystemJarCache.java:60)
... 6 more
I filed an issue on GitHub: https://github.com/jenkinsci/docker-slave/issues/45 As I mentioned there, it seems like this commit could be related, as it's changing the uid of the user in the Docker image: https://github.com/jenkinsci/docker-slave/commit/723d12eea77b5d5bc3082612c12e30e422e237f2 Neither the new uid 1000 nor the previous one 10000 matches the uid of the jenkins user where my build is running (uid:gid is 996:993), so I'm not sure if that's really the reason, but for sure the build was still working until Dec 19, and then I noticed it stopped working when I came back from vacation on Dec 26. This commit was done on Dec 22 and is related to user/permissions, so that's what makes me suspicious  As a workaround I changed the remoting image to specific version jenkins/slave:3.27-1, which was published around 2 months ago according to https://hub.docker.com/r/jenkins/slave/tags. This fixed the issue. |
