Fix local setup issues

[ialidzhikov]

How to categorize this PR?

/area dev-productivity
/kind bug

What this PR does / why we need it:
This PR performs the following changes from the registry-cache extension which are applicable also to this extension:

• Fix make extension-up gardener-extension-registry-cache#277
• Fix skaffold tag generation to generate a new tag on code changes (without local commit) gardener-extension-registry-cache#279

Which issue(s) this PR fixes:
N/A

Special notes for your reviewer:
N/A

Release note:

An issue causing `make extension-up` to fail to patch the ControllerDeployment is now mitigated.

An issue causing `make extension-up` to do NOT generate a new tag for local source code changes is now fixed.

[plkokanov]

Iirc this is only necessary for the ControllerDeployment because we only use the image name and tag - the digest is not available from the $SKAFFOLD_IMAGE env variable or any other variable

In other cases skaffold includes the digest in the image by default when the gitCommit tagPolicy is used - name:tag@sha256:garden.local.gardener.cloud:5001..., that is why in g/g the following is used:
https://github.com/gardener/gardener/blob/01391f78c30a37968fceafd885f0637e689f1909/skaffold.yaml#L1704-L1706

Wdyt about keeping it in line with how it is done in g/g?

[ialidzhikov]

I am not sure that it will work with your suggestion. I haven't tried and I won't have capacity this week to try it out locally.
I am not sure if https://github.com/gardener/gardener/blob/01391f78c30a37968fceafd885f0637e689f1909/skaffold.yaml#L1696-L1706 will help in the case you have changes locally which are not committed. With inputDigest I want to cover the case where you change the code (without local commit) and skaffold generates a new tag.

[plkokanov]

Yep, having changes locally which are not committed is covered. From the tagging docs

When images are pushed, their immutable digest is available. Skaffold then references images both by tag and digest. Something like image:tag@sha256:abacabac.... Using both the tag and the digest seems superfluous but it guarantees immutability and helps users quickly see which version of the image is used.

I also tested it locally. Without any file changes I got the following image for the admission deployment:

image: garden.local.gardener.cloud:5001/local-skaffold_gardener-extension-shoot-rsyslog-relp-admission:v0.7.0-dev-6b6e603-dirty@sha256:f68ae005709b2b217d02d75f50612f2c39c8bf5250909a30f9867f395e591f39

After adding changes to a file, part of the admission, and executing make extensions-up (without committing the changes in git), I got an image with the same tag, but a different sha digest:

image: garden.local.gardener.cloud:5001/local-skaffold_gardener-extension-shoot-rsyslog-relp-admission:v0.7.0-dev-6b6e603-dirty@sha256:852ce3df6d2c7f91b861f42edcefb1f24651e851eb72eef2bcb103f31cf37581

This is how it used to work before. The actual reason for the issue was that we switched to using https://github.com/gardener/gardener-extension-shoot-rsyslog-relp/blob/main/hack/generate-kustomize-patch-controllerdeployment-shoot-rsyslog-relp.sh to generate the ControllerDeployment as the SKAFFOLD_IMAGE env variable does not contain the sha digest that would differ depending on local code changes (it only contains the tag). That's why we need to use inputDigest when building the extension image for the ControllerDeployment to manually add this digest to the tag.

Anyway, I was initially confused that there were no problems some time ago when making local code changes, and by skaffold in gardener where inputDigest was only used for provider-local.

Adding a comment for the extension config here to explain this would be useful. Maybe something in the lines of

inputDigest is used to inject a digest of the artifact source into the built image tag and therefore into the SKAFFOLD_IMAGE environment variable which is used when generating the corresponding ControllerDeployment

[ialidzhikov]

I pushed 3816113 to address your suggestion.

[ialidzhikov]

FYI @rrhubenov as you wanted to the the same changes to the lakom extension.

[plkokanov]

/lgtm
/approve

[gardener-prow]

LGTM label has been added.

Git tree hash: 75f363104025bd0734d939cbaf63862d6aad3bcb

[gardener-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: plkokanov

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:

• OWNERS [plkokanov]

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