Allow UPX compression to be skipped in images

[skitt]

For throw-away images, this saves significant build time whenever images need to be rebuilt. This is enabled for linting jobs: in most cases they don’t involve rebuilding images, but when they do, those images are rebuilt for every linting job, and are then discarded.

Summary by CodeRabbit

• Chores
  • Made binary compression in container images configurable, allowing builds to skip optimization when needed for debugging or compatibility purposes.
  • Fixed a typo in build documentation.

[submariner-bot]

🤖 Created branch: z_pr2408/skitt/disable-upx-images

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: a4152f4e-2e96-40e2-ba89-2bae58f7497e

📥 Commits

Reviewing files that changed from the base of the PR and between 186dd25 and 80eb7ef.

📒 Files selected for processing (5)

• .github/workflows/linting.yml
• Makefile.images
• package/Dockerfile.shipyard-dapper-base
• package/Dockerfile.shipyard-linting
• scripts/shared/build_image.sh

---

Walkthrough

This PR introduces a configurable UPX compression toggle across the build system. It adds an IMAGE_UPX Make variable and corresponding Docker build-argument logic to conditionally enable/disable UPX compression during image builds. When IMAGE_UPX=false, the build pipeline passes UPX_LEVEL=-0 to skip UPX compression in Dockerfiles. The CI linting workflow is updated to disable UPX for these builds.

Changes

Cohort / File(s)	Summary
CI Workflow Configuration .github/workflows/linting.yml	Updated linting workflow run commands to pass IMAGE_UPX=false to all make invocations (gitlint, golangci-lint, markdownlint, packagedoc-lint, shellcheck, govulncheck, yamllint).
Build System Configuration Makefile.images	Added exported Make variable IMAGE_UPX with default value true under the release-images section to control UPX compression behavior.
Docker Image Builds package/Dockerfile.shipyard-dapper-base, package/Dockerfile.shipyard-linting	Added UPX_LEVEL build argument (default -5) and replaced unconditional UPX compression with conditional execution (if test ${UPX_LEVEL} != -0; then ...). Fixed typo in comment ("experemintation" → "experimentation"). Changes affect binary compression in /usr/bin, /usr/lib/golang, /usr/libexec, and /go/bin directories.
Build Script scripts/shared/build_image.sh	Added conditional logic to augment Docker build arguments with UPX_LEVEL=-0 when IMAGE_UPX variable is exactly "false".

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• Switch to govulncheck for Go scanning #2382: Related to UPX handling in Dockerfile exclusions and govulncheck binary compression behavior across the build system.

Suggested reviewers

• vthapar
• sridhargaddam
• tpantelis
• Oats87
• mkolesnik

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The pull request title accurately and clearly summarizes the primary change: allowing UPX compression to be skipped in image builds.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Actionable Comments Resolved	✅ Passed	No actionable comments (TODO, FIXME, XXX, HACK) found in modified files or repository structure.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}