feat(workflows): step 7, add shared Makefile.common and drift check

[seantronsen]

Description

Important

This is a first draft at deduplicating Makefile recipes across the org's repos. I have notes on possible additions that I'll look at later. In the meantime, if you have questions or think something's missing, let me know.

Adds a shared Makefile.common for OpenCHAMI repos and a reusable workflow that catches drift from it.

• Makefile.common: common targets (Go build/test/lint/vuln, Fabrica codegen, containers, GoReleaser packages, REUSE, deps, GNU-style install/uninstall, help, clean) and standard variable names. Repos vendor it at their root, set overrides before include Makefile.common, and keep repo-only targets in their own Makefile. all, deps, build, run, install, and uninstall are double-colon rules so repos can extend them. make build embeds build info into <module>/internal/version (Version, Tag, Branch, Commit, Date, GoVersion, GitState, BuildHost, BuildUser); GO_VERSION_PACKAGE or GO_LDFLAGS overrides it. Targets that don't apply skip (no go.mod, no Fabrica, no Containerfile); GoReleaser targets fail without a config. GNU make 3.81 compatible.
• lint-makefile-common.yml: reusable workflow, no inputs. Resolves this repo's latest release to its commit SHA, fetches Makefile.common at that SHA, and fails with a diff if the caller's copy differs.
• README: entries for both, plus adoption instructions and a GoReleaser ldflags snippet that sets the same internal/version variables, so release binaries and make build report the same build info.

Stacked on #47.

Downstream adoption is separate work and changes target/variable names in adopting repos (e.g. test-coverage → coverage, rpm-build → build-packages, install (dependencies) → deps, BINARY_NAME → PROJECT/BINARIES, main.version ldflags → internal/version).

Checklist

• My code follows the style guidelines of this project
• I have added/updated comments where needed
• I have added tests that prove my fix is effective or my feature works
• I have run make test (or equivalent) locally and all tests pass
• I have updated the relevant documentation (CLI examples, man pages, README, other docs, etc.)
• DCO Sign-off: All commits are signed off (git commit -s) with my real name and email
• REUSE Compliance:
  • Each new/modified source file has SPDX copyright and license headers
  • Any non-commentable files include a <filename>.license sidecar
  • All referenced licenses are present in the LICENSES/ directory

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Dependency update
• Build system/CI

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• I agree to follow the Code of Conduct.

🤖 Generated with Claude Code

[seantronsen]

See OpenCHAMI/github-actions-testbed#11 for test results.