Running Spark in Docker image with Alpine Linux 3.9.0 throws errors when using snappy.
The issue can be reproduced for example as follows: `Seq(1,2).toDF("id").write.format("parquet").save("DELETEME1")`
The key part of the error stack is as follows `SparkException: Task failed while writing rows. .... Caused by: java.lang.UnsatisfiedLinkError: /tmp/snappy-1.1.7-2b4872f1-7c41-4b84-bda1-dbcb8dd0ce4c-libsnappyjava.so: Error loading shared library ld-linux-x86-64.so.2: Noded by /tmp/snappy-1.1.7-2b4872f1-7c41-4b84-bda1-dbcb8dd0ce4c-libsnappyjava.so)`
The source of the error appears to be that libsnappyjava.so needs ld-linux-x86-64.so.2 and looks for it in /lib, while in Alpine Linux 3.9.0 with libc6-compat version 1.1.20-r3 ld-linux-x86-64.so.2 is located in /lib64.
Note: this issue is not present with Alpine Linux 3.8 and libc6-compat version 1.1.19-r10
## What changes were proposed in this pull request?
A possible workaround proposed with this PR is to modify the Dockerfile by adding a symbolic link between /lib and /lib64 so that linux-x86-64.so.2 can be found in /lib. This is probably not the cleanest solution, but I have observed that this is what happened/happens already when using Alpine Linux 3.8.1 (a version of Alpine Linux which was not affected by the issue reported here).
## How was this patch tested?
Manually tested by running a simple workload with spark-shell, using docker on a client machine and using Spark on a Kubernetes cluster. The test workload is: `Seq(1,2).toDF("id").write.format("parquet").save("DELETEME1")`
Added a test to the KubernetesSuite / BasicTestsSuite
Closes#23898 from LucaCanali/dockerfileUpdateSPARK26995.
Authored-by: Luca Canali <luca.canali@cern.ch>
Signed-off-by: Marcelo Vanzin <vanzin@cloudera.com>
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