Build failure in a Docker container

[fmbenhassine]

Trying to build the project inside a Docker container fails with the following error:

[ERROR] Failures:
[ERROR]   FlatFileItemWriterTests.testOpenWithNonWritableFile:536 Should be readonly file: file [/spring-batch/spring-batch-infrastructure/target/no-such-file.foo]
[INFO]
[ERROR] Tests run: 1597, Failures: 1, Errors: 0, Skipped: 16
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for Spring Batch 5.0.0-SNAPSHOT:
[INFO]
[INFO] Spring Batch ....................................... SUCCESS [04:22 min]
[INFO] Spring Batch Infrastructure ........................ FAILURE [01:18 min]
[INFO] Spring Batch Core .................................. SKIPPED
[INFO] Spring Batch Test .................................. SKIPPED
[INFO] Spring Batch Integration ........................... SKIPPED
[INFO] Spring Batch Samples ............................... SKIPPED
[INFO] Spring Batch JSR-352 TCK ........................... SKIPPED
[INFO] Spring Batch Docs .................................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  05:40 min
[INFO] Finished at: 2021-04-21T08:55:27Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.22.2:test (default-test) on project spring-batch-infrastructure: There are test failures.
[ERROR]
[ERROR] Please refer to /spring-batch/spring-batch-infrastructure/target/surefire-reports for the individual test results.
[ERROR] Please refer to dump files (if any exist) [date].dump, [date]-jvmRun[N].dump and [date].dumpstream.
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <args> -rf :spring-batch-infrastructure

Steps to reproduce the issue:

$ docker run -it maven:3-openjdk-8 bash
# git clone https://github.com/spring-projects/spring-batch.git
# cd spring-batch
# ./mvnw package

[dnl50]

I looked into it and it seems like the problem arises in the native implementation the FileSystem#checkAccess Method, which the File#canWrite Method delegates to. The HotSpot Implementation uses the access C Function to check whether the JVM can write to the file (see UnixFileSystem_md.c). As the JVM is run by the root user inside the docker container the access Method returns 0 (= can write), eventhough the file has the correct file mode bits (444) set after the File#setReadOnly method was invoked inside the failing test, since the root user can read and write to every file. The assertion in the testcase therefore fails, since the file is writable.

Running the JVM as a non-root user should fix the problem.

[snate]

I was able to reproduce the issue and the solution proposed by @dnl50 indeed works.
Using an image with a non-root user, for example https://hub.docker.com/r/jtim/maven-non-root, results in a successful build.