Go Upgrade Skill

This skill automates upgrading Go to the latest version and updating all example projects in the repository.

What This Skill Does

1. Upgrades Go to the latest version using Homebrew
2. Detects the newly installed Go version
3. Updates the go directive in all example go.mod files
4. Runs go mod tidy to update dependencies

When to Use

• User asks to "upgrade go"
• User wants to update to the latest Go version
• User mentions updating Go across the project
• After a new Go version is released

Examples to Update

The skill updates these example projects:

• examples/flow/
• examples/ip-counter/
• examples/netkit/
• examples/netkit-ipv6/

Note: examples/trace-kills/ is skipped (no go.mod file)

Step-by-Step Instructions

1. Upgrade Go via Homebrew

brew update
brew upgrade go

Display the output to the user. If Go is already at the latest version, Homebrew will indicate this.

2. Detect New Go Version

go version

Parse the output to extract the version number. The output format is:

go version go1.25.2 darwin/arm64

Extract the version number (e.g., "1.25.2") from the string after "go version go".

3. Update go.mod Files and Run go mod tidy

IMPORTANT: Use absolute paths to avoid shell session issues

First, get the repository root directory:

pwd

Then for each example directory, use the absolute path to update the Go version and tidy dependencies:

cd /absolute/path/to/xcnf/examples/flow && go mod edit -go=<VERSION> && go mod tidy
cd /absolute/path/to/xcnf/examples/ip-counter && go mod edit -go=<VERSION> && go mod tidy
cd /absolute/path/to/xcnf/examples/netkit && go mod edit -go=<VERSION> && go mod tidy
cd /absolute/path/to/xcnf/examples/netkit-ipv6 && go mod edit -go=<VERSION> && go mod tidy

Replace:

• /absolute/path/to/xcnf with the output from pwd (e.g., /Users/username/code/xcnf)
• <VERSION> with the detected version (e.g., "1.25.4")

Why use absolute paths?

• Parallel Bash tool calls run in separate shell sessions
• Relative cd commands don't persist across different tool calls
• Absolute paths ensure each command starts from the correct location

Why combined commands?

• go mod edit -go=X.Y.Z updates the go directive using Go's official tooling
• go mod tidy immediately updates dependencies for the new version
• Running together with && ensures consistency and stops on errors

4. Display Summary

Show the user a summary:

Go Upgrade Summary
==================
Old version: 1.25.1
New version: 1.25.2

Updated go.mod files:
✓ examples/flow/go.mod
✓ examples/ip-counter/go.mod
✓ examples/netkit/go.mod
✓ examples/netkit-ipv6/go.mod

All dependencies tidied successfully.

Error Handling

Homebrew Not Installed

If brew command is not found:

Error: Homebrew is not installed. Please install Homebrew first:
https://brew.sh

Go Upgrade Failed

If brew upgrade go fails, display the error and stop.

Version Parsing Failed

If unable to parse go version output:

Error: Could not detect Go version. Please verify Go is installed correctly.

go mod edit Failed

If any go mod edit command fails, display the error for that specific example and continue with others.

go mod tidy Failed

If go mod tidy fails for any example, display the error and diagnostic information.

Implementation Notes

• Always run commands from the repository root directory
• Use && to chain commands so failures stop execution
• Use absolute paths when running parallel Bash commands
• Display clear output for each step
• Show both successes and failures

Troubleshooting

Shell Session Behavior

Problem: Commands like cd examples/flow && ... fail when run in parallel.

Explanation: Each Bash tool call runs in a separate shell session. When you make parallel calls:

# Call 1 - succeeds
cd examples/flow && go mod edit -go=1.25.4 && go mod tidy

# Call 2 - fails (separate shell, starts from original pwd)
cd examples/ip-counter && go mod edit -go=1.25.4 && go mod tidy

Solution: Always use absolute paths constructed from pwd:

# Get repo root first
REPO_ROOT=$(pwd)

# Then use absolute paths
cd $REPO_ROOT/examples/flow && go mod edit -go=1.25.4 && go mod tidy
cd $REPO_ROOT/examples/ip-counter && go mod edit -go=1.25.4 && go mod tidy
cd $REPO_ROOT/examples/netkit && go mod edit -go=1.25.4 && go mod tidy
cd $REPO_ROOT/examples/netkit-ipv6 && go mod edit -go=1.25.4 && go mod tidy

This ensures each command starts from the correct location regardless of shell session.

Example Usage

User: "Upgrade go to the latest version"

Assistant:

1. Runs brew update && brew upgrade go
2. Detects new version: "1.25.2"
3. Updates all four example go.mod files
4. Runs go mod tidy for each
5. Displays summary of changes