Set GOPROXY in cloudbuild.yaml

[torredil]

Signed-off-by: Eddie Torres torredil@amazon.com

What is this PR about? / Why do we need it?

• The vendor directory was removed in Remove /vendor directory #1328 to address Remove /vendor directory #1326. As a result of this change, we need to account for two scenarios:

  1. For security, a user might want to prevent outgoing connections outside their internal network. Addressed in Pass GOPROXY to image builder #1330.
  2. If GOPROXY is undefined or set to "direct", then go get will use a direct connection to the VCS (e.g github.com). This is causing our build to timeout, since go mod download takes nearly 30 minutes to complete. Addressed by this PR.

---

Why do we need it?

• Dependencies are stored in immutable storage, thus avoiding the risk that any dependency might disappear in the future.
• Protection against actors who might inject malicious code since Go modules cannot be deleted or overridden once stored in the GOPROXY.
• Significantly faster to resolve dependencies since GOPROXY serves the source code over HTTP, thus not requiring the overhead when pulling from a VCS which fetches the whole repository.

---

What testing is done?

• CI

[torredil]

/retest

[rdpsin]

/lgtm
/approve
/hold

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: rdpsin, torredil

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 [rdpsin,torredil]

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

[gtxu]

/lgtm
/unhold