Provide :jre variant

[proppy]

It'd be nice to have :*-jre variant of the images for when you want to build outside of Docker (in your IDE) and just drop JARs in the context.

/cc @ludoch @ndeloof

[tianon]

Yeah, I'd wager this makes sense as the default, and make the JDK variant explicit instead, but I'd love to hear from some Java users about what they'd want from this image before we get too deep into making changes. 😄

[mattgruter]

Java user here. I'd prefer a JRE only variant as the default if this image is to be used as a runtime environment.

[ndeloof]

(Java developer here)
JRE only won't offer JDK diagnostic tools (jstack, jmap, etc) that are very useful even on a production runtime image. Capability to diagnose a badly behaving application using docker-enter (or docker exec ?) and JDK tools is a must have imho.

So you get my +1 for a jre variant, but not as default for java:x official

[tianon]

Heh, funny you should mention docker exec, since it merged this week and will be in 1.3. 😄

[emersonf]

+1 for a JRE variant. Not fussed about whether it's the default or not; it would just be good to have the option to pull in the smaller image instead of rolling my own.

It's also not clear why these images are on sid instead of wheezy, but I'm guessing the stable Debian distribution doesn't have current libraries...?

[yosifkit]

java:8 is on sid; java:7 is on jessie, java:6 is on wheezy.

[emersonf]

Thanks for the correction, hadn't caught that.

What's the motivation behind the different base image versions?

[yosifkit]

That is the only debian that has java 8.
Version 7 is available on wheezy, jessie, and sid. We could move to wheezy for 7.
Version 6 is available on squeeze, wheezy, and sid (wheezy and sid have newer versions).

[remmelt]

See: #14