Render Service Scaling Scripts

Automated scripts to scale Render services using the Render API.

Overview

This repository contains two scripts for scaling Render services:

1. scale_service.py - Full-featured Python script with advanced options
2. scale_service.sh - Quick bash wrapper for simple scaling operations

Prerequisites

• Render API Key (get from your Render dashboard)
• For Python script: Python 3.6+ (uses only standard library)
• For Bash script: bash, curl (jq optional for pretty output)

Authentication

Set your Render API key as an environment variable:

export RENDER_API_KEY="rnd_your_api_key_here"

Or pass it directly via the --api-key flag (Python script only).

Python Script (scale_service.py)

Features

• Absolute scaling (set to specific instance count)
• Relative scaling (increase/decrease by N instances)
• Dry-run mode to preview changes
• Verbose output for debugging
• Fetches current service state before scaling
• Comprehensive error handling

Usage Examples

Scale to absolute number of instances:

python scale_service.py --service-id srv-abc123 --num-instances 5

Increase by relative number:

python scale_service.py --service-id srv-abc123 --increase-by 2

Decrease by relative number:

python scale_service.py --service-id srv-abc123 --decrease-by 1

Dry run (preview without making changes):

python scale_service.py --service-id srv-abc123 --num-instances 10 --dry-run

Verbose output:

python scale_service.py --service-id srv-abc123 --num-instances 5 --verbose

With explicit API key:

python scale_service.py --service-id srv-abc123 --num-instances 5 --api-key rnd_xyz789

Command-line Options

--service-id        Render service ID (required)
--num-instances     Absolute number of instances to scale to
--increase-by       Number of instances to increase by
--decrease-by       Number of instances to decrease by
--api-key           Render API key (or use RENDER_API_KEY env var)
--dry-run           Preview changes without executing
--verbose, -v       Enable verbose output

Bash Script (scale_service.sh)

Features

• Simple and fast
• Single command scaling
• Minimal dependencies

Usage

./scale_service.sh <service-id> <num-instances>

Example

export RENDER_API_KEY="rnd_xyz789"
./scale_service.sh srv-abc123 5

Finding Your Service ID

Your service ID can be found in the Render Dashboard URL when viewing a service:

https://dashboard.render.com/web/srv-abc123def456
                                    ^^^^^^^^^^^^^^^
                                    This is your service ID

Or use the Render API to list your services:

curl -H "Authorization: Bearer $RENDER_API_KEY" \
     https://api.render.com/v1/services

Automation Examples

Cron Job

Scale up during business hours, scale down at night:

# Scale up at 8 AM to 5 instances
0 8 * * * /path/to/scale_service.sh srv-abc123 5

# Scale down at 6 PM to 1 instance
0 18 * * * /path/to/scale_service.sh srv-abc123 1

CI/CD Pipeline

Scale before deployment, scale back after:

# Example GitHub Actions
- name: Scale up before deployment
  run: |
    python scale_service.py --service-id ${{ secrets.SERVICE_ID }} --num-instances 5
  env:
    RENDER_API_KEY: ${{ secrets.RENDER_API_KEY }}

Auto-scaling Script

Combine with monitoring to auto-scale based on load:

#!/bin/bash
# Check CPU usage and scale accordingly
CPU_USAGE=$(get_cpu_usage_from_monitoring)

if [ "$CPU_USAGE" -gt 80 ]; then
    python scale_service.py --service-id srv-abc123 --increase-by 2
elif [ "$CPU_USAGE" -lt 20 ]; then
    python scale_service.py --service-id srv-abc123 --decrease-by 1
fi

API Reference

The scripts use the Render API v1:

• Endpoint: POST https://api.render.com/v1/services/{serviceId}/scale
• Headers:
  • Authorization: Bearer {apiKey}
  • Content-Type: application/json
• Body: {"numInstances": <number>}

Documentation: https://api-docs.render.com/

Error Handling

Both scripts provide clear error messages for common issues:

• Missing or invalid API key
• Service not found
• Invalid instance count
• API rate limiting
• Network errors

Troubleshooting

Authentication Failed:

• Verify your API key is correct
• Check that the key has not expired
• Ensure the key has appropriate permissions

Service Not Found:

• Verify the service ID is correct
• Confirm the service exists in your account

Rate Limiting:

• The Render API has rate limits
• Add delays between multiple scaling operations

Security Notes

• Never commit API keys to version control
• Use environment variables or secret management systems
• Restrict API key permissions to minimum required
• Rotate API keys regularly

License

These scripts are provided as-is for internal use.