Day-08.md

Day 8: Building and Best Practices

Goal: Learn how to build your CLI application and discuss best practices for larger projects.

Steps:

1. Build the executable:

go build -o netcli main.go

Now you have a single netcli executable.

2. Test the executable:

./netcli --help
./netcli ping 8.8.8.8

3. Best Practices:

• Project Structure: For larger projects, organize your cmd directory with sub-directories for related commands (e.g., cmd/device, cmd/config).
• Modular Code: Extract complex logic into separate packages (e.g., pkg/network, pkg/auth) to keep cmd files clean and focused on CLI interaction.
• Interface-based Design: Define interfaces for network device interactions (e.g., NetworkDevice interface { Connect() error; RunCommand(cmd string) (string, error) }) to allow for different device types or protocols.
• Context for Cancellation/Timeouts: Use context.Context for long-running operations or network calls to handle cancellations and timeouts gracefully.
• Testing: Write unit tests for your core logic and integration tests for CLI commands.
• Linter/Static Analysis: Use go vet and tools like golangci-lint to maintain code quality.
• Binary Size Optimization: For very small CLIs, consider go build -ldflags "-s -w" to strip debug symbols and reduce binary size.
• Cross-Compilation: Go's strength is cross-compilation:

GOOS=linux GOARCH=amd64 go build -o netcli_linux_amd64 main.go
GOOS=windows GOARCH=amd64 go build -o netcli_windows_amd64.exe main.go