Upgrade Jib to 1.8.0

[kkowalski]

Description

Upgrade Jib to 1.8.0

User facing changes

N/A

Before

N/A

After

N/A

Next PRs.

N/A

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Adds documentation as needed: user docs, YAML reference, CLI reference.

Reviewer Notes

• The code flow looks good.
• Unit test added.
• User facing changes look good.

Release Notes

- Upgrade Jib to 1.8.0

[codecov]

Codecov Report

Merging #3583 into master will increase coverage by 0.01%.
The diff coverage is n/a.

Impacted Files	Coverage Δ
...affold/kubernetes/portforward/kubectl_forwarder.go	68.29% <0%> (+2.43%)	⬆️

[TadCordle]

Has GCB upgraded gradle yet? #3260 (comment)

[balopat]

Thanks @kkowalski - I'd rather wait for @chanseokoh to confirm that the GCB gradle image is upgraded as @TadCordle pointed out. Thanks @TadCordle!

[kkowalski]

@balopat Sure, should we keep this pr open for now ?

Gcb

[chanseokoh]

The integration test is failing because GCB uses Gradle 4.6 while Jib requires 4.9. (And the next Jib release will require 5.1.)

            An exception occurred applying plugin request [id: 'com.google.cloud.tools.jib', version: '1.8.0']
            > Failed to apply plugin [id 'com.google.cloud.tools.jib']
               > Detected Gradle 4.6, but jib requires Gradle 4.9 or higher. You can upgrade by running 'gradle wrapper --gradle-version=4.9'.

[balopat]

@balopat Sure, should we keep this pr open for now ?

We can keep it open & blocked as an active place for the jib upgrade to check for updates.

[chanseokoh]

GCB is purging the old Gradle 4.6 cache. @kkowalski could you update Jib version to 2.0.0?

[dgageot]

Closing in favour of #3707