[FLINK-20267] JaasModule prevents Flink from starting if working directory is a symbolic link

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.12.0
• Fix Version/s: 1.12.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Assignee: Matthias Pohl
• Reporter: Till Rohrmann
• Created: 20/Nov/20 17:47
• Updated: 20/Oct/22 04:30
• Resolved: 24/Nov/20 15:02

Description

AHeise reported that starting Flink on EMR fails with

java.lang.RuntimeException: unable to generate a JAAS configuration file
        at org.apache.flink.runtime.security.modules.JaasModule.generateDefaultConfigFile(JaasModule.java:170)
        at org.apache.flink.runtime.security.modules.JaasModule.install(JaasModule.java:94)
        at org.apache.flink.runtime.security.SecurityUtils.installModules(SecurityUtils.java:78)
        at org.apache.flink.runtime.security.SecurityUtils.install(SecurityUtils.java:59)
        at org.apache.flink.client.cli.CliFrontend.main(CliFrontend.java:1045)
Caused by: java.nio.file.FileAlreadyExistsException: /tmp
        at sun.nio.fs.UnixException.translateToIOException(UnixException.java:88)
        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:727)
        at org.apache.flink.runtime.security.modules.JaasModule.generateDefaultConfigFile(JaasModule.java:162)
        ... 4 more

The problem is that on EMR /tmp is a symbolic link. Due to FLINK-19252 where we introduced the creation of the working directory in order to create the default Jaas config file, the start up process fails if the path for the working directory is not a directory (apparently Files.createDirectories cannot deal with symbolic links).

Issue Links

• is caused by: FLINK-19252 Jaas file created under io.tmp.dirs - folder not created if not exists
• relates to: FLINK-29698 Job Manager fails with FileAlreadyExistsException if java.io.tmpdir points to a symbolic link
• links to: GitHub Pull Request #14171