jetcd-launcher: allow starting Etcd Container via non-root user on Linux

[linghengqian]

• For io.etcd.jetcd.launcher.EtcdContainer -- Error deleting directory when using jetcd-tests on unit-testing. #1310 .
• Allow starting Etcd Container via non-root user on Linux.
• I verified that on the apache/shardingsphere side, this PR can fix the problem that the temporary directory cannot be deleted after shutting down the container. For example, the owner of /tmp/jetcd_test_etcd0_15814517176251913946/member will be changed to the Linux user logged in on the current host. Although apache/shardingsphere will not benefit from this change due to the need to stay on the jdk8 runtime baseline.
• At least for Ubuntu WSL 22.04.4, uid 1000 will be the current Linux user. This can be verified with cat /etc/passwd. Refer to https://docs.docker.com/engine/reference/run/#user , https://docs.docker.com/engine/security/userns-remap/ and https://www.docker.com/blog/understanding-the-docker-user-instruction/ .

linghengqian@DESKTOP-2OCN434:~/TwinklingLiftWorks/git/public/shardingsphere$ cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
systemd-network:x:100:102:systemd Network Management,,,:/run/systemd:/usr/sbin/nologin
systemd-resolve:x:101:103:systemd Resolver,,,:/run/systemd:/usr/sbin/nologin
messagebus:x:102:105::/nonexistent:/usr/sbin/nologin
systemd-timesync:x:103:106:systemd Time Synchronization,,,:/run/systemd:/usr/sbin/nologin
syslog:x:104:111::/home/syslog:/usr/sbin/nologin
_apt:x:105:65534::/nonexistent:/usr/sbin/nologin
uuidd:x:106:112::/run/uuidd:/usr/sbin/nologin
tcpdump:x:107:113::/nonexistent:/usr/sbin/nologin
linghengqian:x:1000:1000:,,,:/home/linghengqian:/bin/bash
usbmux:x:108:46:usbmux daemon,,,:/var/lib/usbmux:/usr/sbin/nologin
rtkit:x:109:117:RealtimeKit,,,:/proc:/usr/sbin/nologin

• For other systems, I don't have a local verification environment. To test the current PR in other projects, just execute the following command.

sdk install java 17.0.11-ms
sdk use java 17.0.11-ms
git clone git@github.com:linghengqian/jetcd.git -b fix-not-root-user
cd ./jetcd/
./gradlew clean publishToMavenLocal

• Then use it directly.

<dependency>
            <groupId>io.etcd</groupId>
            <artifactId>jetcd-test</artifactId>
            <version>0.8.3-fix-not-root-user-SNAPSHOT</version>
            <scope>test</scope>
</dependency>

[lburgazzoli]

it should not be set to an arbitrary number by default better to leave it empty

[liangyuanpeng]

You are right, once user is set it and then run with specially user, otherwise, not doing anything here at all.

[linghengqian]

• So for the current PR, to resolve io.etcd.jetcd.launcher.EtcdContainer -- Error deleting directory when using jetcd-tests on unit-testing. #1310, either,

@RegisterExtension
    public static final EtcdClusterExtension CLUSTER = EtcdClusterExtension.builder()
            .withNodes(1)
            .withUser("1000:1000")
            .build();

• Or,

@RegisterExtension
    public static final EtcdClusterExtension CLUSTER = EtcdClusterExtension.builder()
            .withNodes(1)
            .withMountDirectory(false)
            .build();

• This still looks weird to me, but I don't want to change the default value of withMountDirectory in this PR. Maybe another friend will need to file a PR to change the unit tests.

[k8s-ci-robot]

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