Nutanix CLI and Bash Scripting Best Practices

Introduction

Bash and Nutanix CLI (ncli, acli) scripting is a powerful combo, but power demands responsibility. From production-level safety to logging and parameter handling, this post outlines essential best practices to help you create clean, robust, and maintainable automation scripts for Nutanix environments.

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My Personal Repository on GitHub

Nutanix Repository on GitHub

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Diagram: Safe Scripting Layers

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Always Use Strict Mode

#!/usr/bin/env bash
set -euo pipefail

• -e: Exit on error
• -u: Treat unset variables as error
• -o pipefail: Fail if any command in a pipeline fails

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Validate Inputs

Avoid unexpected behavior from missing or malformed inputs.

if [[ -z "${1:-}" ]]; then
  echo "Usage: $0 <vm-name>"
  exit 1
fi

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Secure Credential Handling

• Never hardcode passwords
• Use sourced env files or secrets managers
• Lock down file permissions (chmod 600 ~/.nutanix/creds.sh)

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Log Everything

Centralize logs per script for traceability:

log="/var/log/nutanix_$(basename "$0" .sh).log"
echo "[$(date)] Starting script..." >> "$log"

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Handle ncli/acli Errors Gracefully

Wrap critical commands:

if ! ncli cluster get-summary >> "$log" 2>&1; then
  echo "Error fetching cluster summary" >> "$log"
  exit 1
fi

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Organize Scripts into Functions

Structure for reuse and clarity:

create_vm() {
  local vm="$1"
  acli vm.create "$vm" num_vcpus=2 memory=2048
}

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Clean Up Temporary Files

Always remove scratch data or temp credentials:

trap 'rm -f /tmp/tmpfile.$$' EXIT

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Notify on Errors

Email, Slack, or webhook alerts:

mailx -s "Nutanix Script Failed" admin@example.com < "$log"

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Test in Lab First

Always validate scripts against a test cluster before running in production.

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Schedule Sanely

Stagger cron jobs to avoid contention:

0 4 * * * /usr/local/bin/nutanix_vm_backup.sh
15 4 * * * /usr/local/bin/nutanix_vm_audit.sh

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Summary

Following these Bash and Nutanix CLI best practices ensures your scripts are safe, maintainable, and enterprise-ready. Build automation like you’d build infrastructure: with reliability, observability, and recoverability in mind.

External Documentation:

• Nutanix ncli Command Reference