Is it possible to have eclipse-temurin:8-jre-focal variant?

[tahir-uniscon]

I need a Jetty docker image based on Eclipse Temurin JRE8.
I see a Eclipse Temurin JDK8 is currently supported but not JRE8.

I have tried to build the eclipse-temurin:8-jre-focal variant locally and it seems to work fine.

Is it possible to add it to default set of supported variants?
I am willing to create a pull request if needed

[joakime]

Jetty 9.x are the only releases to support Java 8.

Jetty 9.x is now at End of Community Support.

See: jetty/jetty.project#7958

Jetty 10.x+ have a minimum Java 11 requirement.
Jetty 12.x+ has a minimum Java 17 requirement.

[tahir-uniscon]

@joakime Thanks for your reply
I just noticed that openjdk/9.4/jre8-slim is not available in this project's master branch.
Does that mean that this is also not being maintained anymore?

[joakime]

openjdk is not a valid/supported docker image anymore (at the docker side)

See:

• Update openjdk docker-library/official-images#12851
• Drop openjdk entirely #106

[tahir-uniscon]

Got it.
But if I understand correctly, eclipse temurin is still supporting/maintaining both JDK8 and JRE8 docker base images.
Do you think jetty.docker can add support for JRE8 through eclipse-temurin:8-jre-*?
In production environments it makes sense to use JRE based Jetty instead of JDK

[joakime]

Several components in Jetty need a JDK. (eg: JSP, etc).

Looking at the eclipse-temurin releases for Java 11.
The difference in JRE vs JDK releases is ...

1. The "jre" release is missing binaries (in <java-home>/bin/) for ...

jps
jshell
jmod
jar
jimage
rmic
javac
jinfo
jdb
jhsdb
jstat
jconsole
serialver
jlink
jcmd
jdeps
javap
jarsigner
javadoc
jdeprscan
jmap
jstatd
jstack

2. The "jre" is missing includes for compiling JNI based code.
3. The "jre" documentation for the above removed binaries are removed.
4. The "jre" is missing the src.zip
5. The "jre" is missing the "attach" native/shared libs
6. The "jre" is missing /jmods/ tree (makes sense as jlink is removed)

That's it.
The classlib (well, lib/modules) in "jre" is full and complete and seemingly identical to the "jdk" version.
That means it still has the compiler classes, just not the javac binary.

[tahir-uniscon]

Right. Using JRE based image in production is preferable for same reason that it has smaller foot print and less chance of vulnerabilities due to lower number of executables. JSP is optional dependency and many Java web apps don't use JSP (especially true for API based backends)

[tahir-uniscon]

Also jetty.docker still has JRE8 and JRE11 base variants

[joakime]

Also jetty.docker still has JRE8 and JRE11 base variants

Only Jetty 9 (which is at End of Community Support) has Java 8 variants.

Those on Jetty 10+, using Java 11+, have other options than a JRE release.
Those that care about reduced footprint use jlink to build custom Java releases for their exact limited usecase. (a result that is far smaller in size than even a JRE).

[tahir-uniscon]

Thanks for creating the PR.
Is there any ETA for the PR to get merged and the new variant images becoming available on docker hub?

[joakime]

@tahir-uniscon our priority atm is the jetty releases that are in progress ...

• Jetty Releases 9.4.49 jetty.project#8555
• Jetty Releases 10.0.12, 11.0.12 jetty.project#8557

[lachlan-roberts]

The JRE variants are now available.
See full list of supported tags at https://hub.docker.com/_/jetty.