fix(sdk): visualizations and metrics do not work with data_passing_methods

[juliusvonkohout]

Description of your changes:

I made changes such that mlpipeline-ui-metadata and mlpipeline-metrics are always kept as artifacts, such that the webinterface can access and display them even if we use a kubernetes volume as data passing method.

@Bobgy we could also extend this to allow the user to specify additional outputs that should also be kept as artifacts.

....
pipeline_configuration = kfp.dsl.PipelineConf()
from kubernetes.client.models import V1Volume, V1PersistentVolumeClaimVolumeSource
from kfp.dsl import data_passing_methods
pipeline_configuration.data_passing_method = data_passing_methods.KubernetesVolume(
    volume=V1Volume(
        name='artefacts',
        persistent_volume_claim=V1PersistentVolumeClaimVolumeSource("{{workflow.name}}-%s" % 'artefacts'),
    ),
    path_prefix='artefacts/'
)

Checklist:

• The title for your pull request (PR) should follow our title convention. Learn more about the pull request title convention used in this repository.

[google-oss-prow]

Hi @juliusvonkohout. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[google-oss-prow]

@juliusvonkohout: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

In response to this:

/ok-to-test

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[juliusvonkohout]

@juliusvonkohout: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

@Bobgy is it possible for me to become a trusted user?

[juliusvonkohout]

@chensun @ji-yaqi can i get an /ok-to-test

[chensun]

/ok-to-test

[juliusvonkohout]

Ok, I just need to fix the expected test results pipelines/sdk/python/tests/compiler/testdata/artifact_passing_using_volume.yaml

[Bobgy]

@juliusvonkohout you can request to join kubeflow org in https://github.com/kubeflow/internal-acls

[juliusvonkohout]

/retest

[juliusvonkohout]

1. I have updated my changes to pass all tests locally (it was just an empty artifacts list in outputs that failed the test)
2. I have extended the unittest to make sure that visualizations and metrics are tested.

So from my side is it ready to merge @chensun

[chensun]

/lgtm
/approve

Thanks!

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: chensun

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• sdk/OWNERS [chensun]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment