RFR: Add support for offline and local builds

[Jorn Vernee]

On Tue, 5 Nov 2019 13:15:24 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> this patch adds much improved support for both _offline_ and _local_ builds. We are currently downloading both JDK and Gradle distributions for the most common platforms (GNU/Linux x64, macOS x64 and Windows x64), but this scheme does not scale to multiple other operating systems and/or CPU architectures. I have therefore extended the `images` plugin to support a `local` image which uses the JDK that is currently executing Gradle for producing the jlinked image.
> 
> I also added support for fully offline builds for those want to supply both a JDK and Gradle themselves and ensure that the build does not download anything.
> 
> Thanks,
> Erik
> 
> ## Testing
> - Tested multiple variants of builds, including local, offline and default builds
> 
> ----------------
> 
> Commits:
>  - 66a6b56b: Added support for offline and local builds
> 
> Changes: https://git.openjdk.java.net/skara/pull/237/files
>  Webrev: https://webrevs.openjdk.java.net/skara/237/webrev.00
>   Stats: 300 lines in 10 files changed: 207 ins; 22 del; 71 mod
>   Patch: https://git.openjdk.java.net/skara/pull/237.diff
>   Fetch: git fetch https://git.openjdk.java.net/skara pull/237/head:pull/237

build.gradle line 125:

> 124: def getCPU() {
> 125:     def cpu = System.getProperty('os.arch').toLowerCase()
> 126:     if (cpu.startsWith('amd64')) {

I think this is x86_64 on Mac for 64 bit platforms

PR: https://git.openjdk.java.net/skara/pull/237