bump-kubelogin

name	bump-kubelogin
description	Bump the kubelogin Homebrew formula to a new upstream release version. Triggers: "bump kubelogin", "update kubelogin", "kubelogin version bump", "new kubelogin release", "upgrade kubelogin".
allowed-tools	Read, Write, Edit, Glob, Grep, Bash(gh:*), Bash(git:*), Bash(curl:*), Bash(grep:*)

Skill: Bump kubelogin Version

Bump the kubelogin Homebrew formula to a new upstream release version.

Overview

This skill updates the two Homebrew formula files (Formula/kubelogin.rb and Formula/az-kubelogin.rb) to a new kubelogin release version. Both files share the same version string and SHA256 checksums -- only the installed binary name differs.

What Changes Per Version Bump

Each bump modifies exactly 4 values in 2 files (8 edits total):

Value	Line pattern
Version string	version "X.Y.Z" (line 7)
darwin-amd64 SHA256	sha256 after kubelogin-darwin-amd64.zip URL (line 13)
darwin-arm64 SHA256	sha256 after kubelogin-darwin-arm64.zip URL (line 16)
linux-amd64 SHA256	sha256 after kubelogin-linux-amd64.zip URL (line 19)

Files to update:

• Formula/kubelogin.rb
• Formula/az-kubelogin.rb

Workflow

Step 1: Determine Target Version

If the user provides a version (e.g., "bump kubelogin to 0.2.16"), use that version. Strip any leading v prefix.

If no version is provided, auto-detect the latest release:

gh release view --repo Azure/kubelogin --json tagName --jq '.tagName' | sed 's/^v//'

Step 2: Read Current Version

Extract the current version from the formula:

grep -m1 'version "' Formula/kubelogin.rb | sed 's/.*version "\(.*\)"/\1/'

If the current version equals the target version, inform the user that the formula is already up to date and stop.

Step 3: Branch Hygiene

Follow the standard branch hygiene protocol:

git fetch origin
git checkout master
git reset --hard origin/master
git checkout -b update-kubelogin-v<VERSION>

Step 4: Fetch SHA256 Checksums

Download the .sha256 checksum files from the GitHub release for all 3 platforms:

ARCHIVES=("kubelogin-darwin-amd64.zip" "kubelogin-darwin-arm64.zip" "kubelogin-linux-amd64.zip")
for archive in "${ARCHIVES[@]}"; do
  curl -sL "https://github.com/Azure/kubelogin/releases/download/v<VERSION>/${archive}.sha256"
done

Each .sha256 file contains a line like: <64-char-hex> <filename>

Extract just the hex hash from each. Validate that each hash is exactly 64 hex characters. If any download fails or hash is malformed, stop and report the error.

Assign the results:

• SHA_DARWIN_AMD64 = hash from kubelogin-darwin-amd64.zip.sha256
• SHA_DARWIN_ARM64 = hash from kubelogin-darwin-arm64.zip.sha256
• SHA_LINUX_AMD64 = hash from kubelogin-linux-amd64.zip.sha256

Step 5: Update Both Formula Files

For each of Formula/kubelogin.rb and Formula/az-kubelogin.rb, make exactly 4 edits using the Edit tool:

1. Version string: Replace version "<OLD_VERSION>" with version "<NEW_VERSION>"
2. darwin-amd64 sha256: Replace the sha256 "..." on the line after the kubelogin-darwin-amd64.zip URL
3. darwin-arm64 sha256: Replace the sha256 "..." on the line after the kubelogin-darwin-arm64.zip URL
4. linux-amd64 sha256: Replace the sha256 "..." on the line after the kubelogin-linux-amd64.zip URL

Use precise context (include the url line above each sha256 line) to ensure the Edit tool matches the correct location.

Example edit for darwin-amd64 in kubelogin.rb:

oldString:

    url "https://github.com/Azure/kubelogin/releases/download/v#{version}/kubelogin-darwin-amd64.zip"
    sha256 "<OLD_HASH>"

newString:

    url "https://github.com/Azure/kubelogin/releases/download/v#{version}/kubelogin-darwin-amd64.zip"
    sha256 "<NEW_HASH>"

Repeat the same pattern for darwin-arm64 and linux-amd64 in both files.

Step 6: Verify Changes

After editing, read both files to confirm:

• The version string is correct
• All 3 SHA256 hashes are updated and match the downloaded values
• No other lines were changed
• Both files have identical version and checksums

Run git diff to review the changes -- there should be exactly 8 lines changed per file (4 removed, 4 added).

Step 7: Commit and Push

git add Formula/kubelogin.rb Formula/az-kubelogin.rb
git commit -m "Bump kubelogin to v<VERSION>"
git push -u origin update-kubelogin-v<VERSION>

Step 8: Create Pull Request

Create a PR targeting master:

gh pr create \
  --title "Bump kubelogin to v<VERSION>" \
  --body "## Summary
- Bumps kubelogin from v<OLD_VERSION> to v<VERSION>
- Updates SHA256 checksums for all 3 platforms (darwin-amd64, darwin-arm64, linux-amd64)

**Release:** https://github.com/Azure/kubelogin/releases/tag/v<VERSION>" \
  --base master

Report the PR URL to the user.

Error Handling

• If gh release view fails, the version may not exist. Ask the user to verify.
• If any .sha256 file download returns a 404, the release assets may not be published yet. Inform the user.
• If SHA256 values are not valid 64-character hex strings, stop and report the issue.
• If a branch named update-kubelogin-v<VERSION> already exists remotely, inform the user and ask how to proceed.

Notes

• The repo also contains get-sha256.sh which can be used as an alternative to manually curling checksums: KUBELOGIN_VERSION=<VERSION> ./get-sha256.sh
• The upstream release page is: https://github.com/Azure/kubelogin/releases
• The default branch is master (not main)