HADOOP-18119. ViewFileSystem#getUri should return a URI with an empty path component

[cheyu2022]

Description of PR

The goal here is that the semantics of FileSystem#getURI() remains the same as before when using ViewFileSystem.

We should assume that the URI returned by FileSystem#getURI() doesn't have a Path component (i.e., path component is null). DistributedFileSystem follows this pattern. However, ViewFileSystem add "/" as the path component in the URI returned.

How was this patch tested?

mvn test -Dtest=TestViewFileSystem*

For code changes:

• Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')?
• Object storage: have the integration tests been executed and the endpoint declared according to the connector-specific documentation?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• If applicable, have you updated the LICENSE, LICENSE-binary, NOTICE-binary files?

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 47s		Docker mode activated.
			_ Prechecks _
+1 💚	dupname	0m 1s		No case conflicting files found.
+0 🆗	codespell	0m 0s		codespell was not available.
+1 💚	@author	0m 0s		The patch does not contain any @author tags.
+1 💚	test4tests	0m 0s		The patch appears to include 3 new or modified test files.
			_ trunk Compile Tests _
+0 🆗	mvndep	110m 0s		Maven dependency ordering for branch
+1 💚	mvninstall	33m 53s		trunk passed
+1 💚	compile	22m 38s		trunk passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	compile	19m 37s		trunk passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	checkstyle	3m 36s		trunk passed
+1 💚	mvnsite	3m 53s		trunk passed
+1 💚	javadoc	3m 29s		trunk passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javadoc	3m 35s		trunk passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	5m 58s		trunk passed
+1 💚	shadedclient	23m 9s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+0 🆗	mvndep	0m 28s		Maven dependency ordering for patch
+1 💚	mvninstall	2m 15s		the patch passed
+1 💚	compile	21m 46s		the patch passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javac	21m 46s		the patch passed
+1 💚	compile	19m 44s		the patch passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	javac	19m 44s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	checkstyle	3m 30s		the patch passed
+1 💚	mvnsite	3m 21s		the patch passed
+1 💚	javadoc	2m 35s		the patch passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javadoc	3m 34s		the patch passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	6m 14s		the patch passed
+1 💚	shadedclient	23m 11s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	unit	17m 32s		hadoop-common in the patch passed.
-1 ❌	unit	228m 57s	/patch-unit-hadoop-hdfs-project_hadoop-hdfs.txt	hadoop-hdfs in the patch passed.
+1 💚	asflicense	1m 11s		The patch does not generate ASF License warnings.
		564m 28s

Reason	Tests
Failed junit tests	hadoop.hdfs.TestViewDistributedFileSystemWithMountLinks

Subsystem	Report/Notes
Docker	ClientAPI=1.41 ServerAPI=1.41 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/1/artifact/out/Dockerfile
GITHUB PR	#3979
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell
uname	Linux d34c49d6f560 4.15.0-156-generic #163-Ubuntu SMP Thu Aug 19 23:31:58 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 0ee196a04d59c815d7cf5e7b88771fa7016f62bc
Default Java	Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
Multi-JDK versions	/usr/lib/jvm/java-11-openjdk-amd64:Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04 /usr/lib/jvm/java-8-openjdk-amd64:Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
Test Results	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/1/testReport/
Max. process+thread count	3688 (vs. ulimit of 5500)
modules	C: hadoop-common-project/hadoop-common hadoop-hdfs-project/hadoop-hdfs U: .
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/1/console
versions	git=2.25.1 maven=3.6.3 spotbugs=4.2.2
Powered by	Apache Yetus 0.14.0-SNAPSHOT https://yetus.apache.org

This message was automatically generated.

[hadoop-yetus]

💔 -1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 36s		Docker mode activated.
			_ Prechecks _
+1 💚	dupname	0m 0s		No case conflicting files found.
+0 🆗	codespell	0m 0s		codespell was not available.
+1 💚	@author	0m 0s		The patch does not contain any @author tags.
+1 💚	test4tests	0m 0s		The patch appears to include 3 new or modified test files.
			_ trunk Compile Tests _
+0 🆗	mvndep	12m 50s		Maven dependency ordering for branch
+1 💚	mvninstall	21m 37s		trunk passed
+1 💚	compile	22m 15s		trunk passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	compile	19m 40s		trunk passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	checkstyle	3m 35s		trunk passed
+1 💚	mvnsite	3m 23s		trunk passed
+1 💚	javadoc	2m 29s		trunk passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javadoc	3m 28s		trunk passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	5m 50s		trunk passed
+1 💚	shadedclient	23m 8s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+0 🆗	mvndep	0m 29s		Maven dependency ordering for patch
+1 💚	mvninstall	2m 15s		the patch passed
+1 💚	compile	21m 40s		the patch passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javac	21m 40s		the patch passed
+1 💚	compile	19m 44s		the patch passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	javac	19m 44s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	checkstyle	3m 34s		the patch passed
+1 💚	mvnsite	3m 17s		the patch passed
+1 💚	javadoc	2m 24s		the patch passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javadoc	3m 32s		the patch passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	6m 19s		the patch passed
+1 💚	shadedclient	23m 14s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	unit	17m 49s		hadoop-common in the patch passed.
-1 ❌	unit	224m 43s	/patch-unit-hadoop-hdfs-project_hadoop-hdfs.txt	hadoop-hdfs in the patch passed.
+1 💚	asflicense	1m 11s		The patch does not generate ASF License warnings.
		448m 24s

Reason	Tests
Failed junit tests	hadoop.hdfs.TestViewDistributedFileSystemWithMountLinks
	hadoop.hdfs.TestRollingUpgrade

Subsystem	Report/Notes
Docker	ClientAPI=1.41 ServerAPI=1.41 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/2/artifact/out/Dockerfile
GITHUB PR	#3979
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell
uname	Linux 163ac19c85e6 4.15.0-58-generic #64-Ubuntu SMP Tue Aug 6 11:12:41 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / a85ff0d8966276a5658e77b459784cff02220da1
Default Java	Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
Multi-JDK versions	/usr/lib/jvm/java-11-openjdk-amd64:Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04 /usr/lib/jvm/java-8-openjdk-amd64:Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
Test Results	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/2/testReport/
Max. process+thread count	3197 (vs. ulimit of 5500)
modules	C: hadoop-common-project/hadoop-common hadoop-hdfs-project/hadoop-hdfs U: .
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/2/console
versions	git=2.25.1 maven=3.6.3 spotbugs=4.2.2
Powered by	Apache Yetus 0.14.0-SNAPSHOT https://yetus.apache.org

This message was automatically generated.

[hadoop-yetus]

🎊 +1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 39s		Docker mode activated.
			_ Prechecks _
+1 💚	dupname	0m 0s		No case conflicting files found.
+0 🆗	codespell	0m 0s		codespell was not available.
+1 💚	@author	0m 0s		The patch does not contain any @author tags.
+1 💚	test4tests	0m 0s		The patch appears to include 2 new or modified test files.
			_ trunk Compile Tests _
+1 💚	mvninstall	32m 6s		trunk passed
+1 💚	compile	22m 18s		trunk passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	compile	19m 33s		trunk passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	checkstyle	1m 7s		trunk passed
+1 💚	mvnsite	1m 41s		trunk passed
+1 💚	javadoc	1m 13s		trunk passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javadoc	1m 45s		trunk passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	2m 30s		trunk passed
+1 💚	shadedclient	22m 8s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	mvninstall	0m 57s		the patch passed
+1 💚	compile	21m 40s		the patch passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javac	21m 40s		the patch passed
+1 💚	compile	19m 45s		the patch passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	javac	19m 45s		the patch passed
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	checkstyle	1m 7s		the patch passed
+1 💚	mvnsite	1m 39s		the patch passed
+1 💚	javadoc	1m 12s		the patch passed with JDK Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04
+1 💚	javadoc	1m 43s		the patch passed with JDK Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
+1 💚	spotbugs	2m 39s		the patch passed
+1 💚	shadedclient	22m 23s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	unit	17m 41s		hadoop-common in the patch passed.
+1 💚	asflicense	0m 54s		The patch does not generate ASF License warnings.
		196m 55s

Subsystem	Report/Notes
Docker	ClientAPI=1.41 ServerAPI=1.41 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/3/artifact/out/Dockerfile
GITHUB PR	#3979
Optional Tests	dupname asflicense compile javac javadoc mvninstall mvnsite unit shadedclient spotbugs checkstyle codespell
uname	Linux 530bf60df458 4.15.0-156-generic #163-Ubuntu SMP Thu Aug 19 23:31:58 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 2dc341c
Default Java	Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
Multi-JDK versions	/usr/lib/jvm/java-11-openjdk-amd64:Ubuntu-11.0.13+8-Ubuntu-0ubuntu1.20.04 /usr/lib/jvm/java-8-openjdk-amd64:Private Build-1.8.0_312-8u312-b07-0ubuntu1~20.04-b07
Test Results	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/3/testReport/
Max. process+thread count	1258 (vs. ulimit of 5500)
modules	C: hadoop-common-project/hadoop-common U: hadoop-common-project/hadoop-common
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-3979/3/console
versions	git=2.25.1 maven=3.6.3 spotbugs=4.2.2
Powered by	Apache Yetus 0.14.0-SNAPSHOT https://yetus.apache.org

This message was automatically generated.

[github-actions]

We're closing this stale PR because it has been open for 100 days with no activity. This isn't a judgement on the merit of the PR in any way. It's just a way of keeping the PR queue manageable.
If you feel like this was a mistake, or you would like to continue working on it, please feel free to re-open it and ask for a committer to remove the stale tag and review again.
Thanks all for your contribution.