HADOOP-17635. Update the ubuntu version in the build instruction.

[iwasakims]

https://issues.apache.org/jira/browse/HADOOP-17635

The setup procedure of Ubuntu 18.04 is defferent from 20.04. Uses of Ubuntu 18.04 need to install gcc-9 from supplemental repository and cmake >= 3.19 from source code. Leaving current instruction for Ubuntu 18.04 could be useful until majority of users move to 20.04.

Oracle Java(JDK) 8 is not available now. I replaced it with OpenJDK 8.
https://launchpad.net/~webupd8team/+archive/ubuntu/java

I tested the procedure on fresh Unbuntu 18.04 environment (on EC2 using ami-0ef85cf6e604e5650).

$ uname -a
Linux ip-172-31-18-242 5.4.0-1038-aws #40~18.04.1-Ubuntu SMP Sat Feb 6 01:56:56 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

$ cat /etc/os-release
NAME="Ubuntu"
VERSION="18.04.5 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.5 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

$ mvn clean install -DskipTests -DskipShade -Drequire.isal -Drequire.pmdk -Pnative -Pdist

$ ./hadoop-dist/target/hadoop-3.4.0-SNAPSHOT/bin/hadoop checknative
2021-04-19 04:23:17,621 INFO bzip2.Bzip2Factory: Successfully loaded & initialized native-bzip2 library system-native
2021-04-19 04:23:17,625 INFO zlib.ZlibFactory: Successfully loaded & initialized native-zlib library
2021-04-19 04:23:17,758 INFO nativeio.NativeIO: The native code was built with PMDK support, and PMDK libs were loaded successfully.
Native library checking:
hadoop:  true /home/ubuntu/hadoop/hadoop-dist/target/hadoop-3.4.0-SNAPSHOT/lib/native/libhadoop.so.1.0.0
zlib:    true /lib/x86_64-linux-gnu/libz.so.1
zstd  :  true /usr/lib/x86_64-linux-gnu/libzstd.so.1
bzip2:   true /lib/x86_64-linux-gnu/libbz2.so.1
openssl: true /usr/lib/x86_64-linux-gnu/libcrypto.so
ISA-L:   true /usr/lib/libisal.so.2
PMDK:    true /usr/local/lib/libpmem.so.1.0.0

[aajisaka]

LGTM. Thank you @iwasakims

[hadoop-yetus]

🎊 +1 overall

Vote	Subsystem	Runtime	Logfile	Comment
+0 🆗	reexec	0m 50s		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.
			_ trunk Compile Tests _
+1 💚	shadedclient	25m 9s		branch has no errors when building and testing our client artifacts.
			_ Patch Compile Tests _
+1 💚	blanks	0m 0s		The patch has no blanks issues.
+1 💚	shadedclient	15m 39s		patch has no errors when building and testing our client artifacts.
			_ Other Tests _
+1 💚	asflicense	0m 30s		The patch does not generate ASF License warnings.
		43m 42s

Subsystem	Report/Notes
Docker	ClientAPI=1.41 ServerAPI=1.41 base: https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-2931/1/artifact/out/Dockerfile
GITHUB PR	#2931
Optional Tests	dupname asflicense codespell
uname	Linux d6108ed91f79 4.15.0-126-generic #129-Ubuntu SMP Mon Nov 23 18:53:38 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
Build tool	maven
Personality	dev-support/bin/hadoop.sh
git revision	trunk / 364d9c3
Max. process+thread count	516 (vs. ulimit of 5500)
modules	C: . U: .
Console output	https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-2931/1/console
versions	git=2.25.1 maven=3.6.3
Powered by	Apache Yetus 0.14.0-SNAPSHOT https://yetus.apache.org

This message was automatically generated.

[iwasakims]

Thanks, @aajisaka.