gcp-cli

gcp-cli Best Practices

The gcloud CLI is your primary interface for Google Cloud. These guidelines ensure your gcloud scripts and commands are reliable, secure, and easy to maintain, adhering to Google's own Shell Style Guide and modern cloud security principles.

1. Code Organization and Structure

Always structure your shell scripts for readability and robustness. Use bash and adhere to a consistent style.

• Use Bash with Strict Mode: Always start scripts with the correct shebang and enable strict mode for early error detection.

  • #!/usr/bin/env bash
  • set -euo pipefail ensures scripts exit on error, undefined variables, and pipe failures.
  • IFS=$'\n\t' prevents unexpected word splitting.

  ❌ BAD:

  #!/bin/sh
  # No strict mode, prone to silent failures
  gcloud compute instances list --format="value(name)" | while read instance; do
    echo "Processing $instance"
    # ... potentially fails silently if gcloud command exits non-zero
  done
  

  ✅ GOOD:

  #!/usr/bin/env bash
  set -euo pipefail
  IFS=$'\n\t'
  
  # Function for consistent error logging
  err() {
    echo "[$(date +'%Y-%m-%dT%H:%M:%S%z')]: $*" >&2
  }
  
  main() {
    # Explicitly set project for clarity and safety
    local PROJECT_ID="your-gcp-project-id"
  
    # Example: Iterate and process instances
    gcloud compute instances list --project="${PROJECT_ID}" --format="value(name)" | while read -r instance; do
      echo "Processing instance: ${instance}"
      # Perform gcloud operation, check exit code if not using set -e for specific commands
      if ! gcloud compute instances stop "${instance}" --project="${PROJECT_ID}" --zone="us-central1-a" --quiet; then
        err "Failed to stop instance: ${instance}"
        exit 1 # Exit script on critical failure
      fi
    done
  }
  
  main "$@"
  

• Functions for Reusability: Encapsulate logic in functions. Use local for function-scoped variables.

  • Include clear function comments (description, globals, arguments, outputs, returns).