Bug: s3a: bucket names with dots cannot be used
Status: Resolved | Priority: Minor | Resolution: Invalid
Created: 01/Sep/20 14:40
Affects Version/s: 3.0.0

Running vanilla spark with
{noformat}
--packages=org.apache.hadoop:hadoop-aws:x.y.z{noformat}
I cannot read from S3, if the bucket name contains a dot (a valid name).

A minimal reproducible example looks like this
{{from pyspark.sql import SparkSession}}
{{import pyspark.sql.functions as f}}
{{if __name__ == '__main__':}}
{{  spark = (SparkSession}}
{{    .builder}}
{{    .appName('my_app')}}
{{    .master("local[*]")}}
{{    .getOrCreate()}}
{{  )}}

{{  spark.read.csv("s3a://test-bucket-name-v1.0/foo.csv")}}

Or just launch a spark-shell with `--packages=(...)hadoop-aws(...)` and read that CSV. I created the same bucket without the period and it worked fine.

*Now I'm not sure whether this is a thing of prepping the path names and passing them to the aws-sdk, or whether the fault is within the SDK itself. I am not Java savvy to investigate the issue further, but I tried to make the repro as short as possible.*

----

I get different errors depending on which Hadoop distributions I use. If I use the default PySpark distribution (which includes Hadoop 2), I get the following (using hadoop-aws:2.7.4)

{{scala> spark.read.csv("s3a://okokes-test-v2.5/foo.csv").show()}}
{{java.lang.IllegalArgumentException: The bucketName parameter must be specified.}}
{{ at com.amazonaws.services.s3.AmazonS3Client.assertParameterNotNull(AmazonS3Client.java:2816)}}
{{ at com.amazonaws.services.s3.AmazonS3Client.headBucket(AmazonS3Client.java:1026)}}
{{ at com.amazonaws.services.s3.AmazonS3Client.doesBucketExist(AmazonS3Client.java:994)}}
{{ at org.apache.hadoop.fs.s3a.S3AFileSystem.initialize(S3AFileSystem.java:297)}}
{{ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2669)}}
{{ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:94)}}
{{ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2703)}}
{{ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2685)}}
{{ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:373)}}
{{ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)}}
{{ at org.apache.spark.sql.execution.streaming.FileStreamSink$.hasMetadata(FileStreamSink.scala:46)}}
{{ at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:361)}}
{{ at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:279)}}
{{ at org.apache.spark.sql.DataFrameReader.$anonfun$load$2(DataFrameReader.scala:268)}}
{{ at scala.Option.getOrElse(Option.scala:189)}}
{{ at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:268)}}
{{ at org.apache.spark.sql.DataFrameReader.csv(DataFrameReader.scala:705)}}
{{ at org.apache.spark.sql.DataFrameReader.csv(DataFrameReader.scala:535)}}
{{ ... 47 elided}}

When I downloaded 3.0.0 with Hadoop 3 and ran a spark-shell there, I got this error (with hadoop-aws:3.2.0):

{{java.lang.NullPointerException: null uri host.}}
{{ at java.base/java.util.Objects.requireNonNull(Objects.java:246)}}
{{ at org.apache.hadoop.fs.s3native.S3xLoginHelper.buildFSURI(S3xLoginHelper.java:71)}}
{{ at org.apache.hadoop.fs.s3a.S3AFileSystem.setUri(S3AFileSystem.java:470)}}
{{ at org.apache.hadoop.fs.s3a.S3AFileSystem.initialize(S3AFileSystem.java:235)}}
{{ at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:3303)}}
{{ at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:124)}}
{{ at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:3352)}}
{{ at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:3320)}}
{{ at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:479)}}
{{ at org.apache.hadoop.fs.Path.getFileSystem(Path.java:361)}}
{{ at org.apache.spark.sql.execution.streaming.FileStreamSink$.hasMetadata(FileStreamSink.scala:46)}}
{{ at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:361)}}
{{ at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:279)}}
{{ at org.apache.spark.sql.DataFrameReader.$anonfun$load$2(DataFrameReader.scala:268)}}
{{ at scala.Option.getOrElse(Option.scala:189)}}
{{ at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:268)}}
{{ at org.apache.spark.sql.DataFrameReader.csv(DataFrameReader.scala:705)}}
{{ at org.apache.spark.sql.DataFrameReader.csv(DataFrameReader.scala:535)}}
{{ ... 47 elided}}