Overview

Instructions

Step 1: API Key Management Per Environment

# Development: store in .env.local
echo "VAST_API_KEY=dev_key_abc123" >> .env.local
echo "VAST_MAX_PRICE_PER_HR=0.40" >> .env.local   # max $/hr for dev instances

# Staging: GitHub Actions environment secrets
# Add VAST_API_KEY_STAGING to staging environment

# Production: AWS Secrets Manager or similar
aws secretsmanager create-secret \
  --name vast/production/api-key \
  --secret-string "prod_key_xyz789"

Step 2: Environment-Aware Vast.ai Configuration

# config/vastai.py
import os
from dataclasses import dataclass

@dataclass
class VastAIConfig:
    api_key: str
    max_price_per_hr: float       # maximum $/hr to spend on an instance
    allowed_gpu_types: list[str]  # GPU whitelist
    max_instances: int
    spot_only: bool               # restrict to interruptible spot instances

ENV_CONFIGS = {
    "development": VastAIConfig(
        api_key=os.environ.get("VAST_API_KEY", ""),
        max_price_per_hr=0.40,    # RTX 3090 range
        allowed_gpu_types=["RTX_3090", "RTX_4090", "RTX_3080"],
        max_instances=2,
        spot_only=True,           # spot only in dev to minimize cost
    ),
    "staging": VastAIConfig(
        api_key=os.environ.get("VAST_API_KEY_STAGING", ""),
        max_price_per_hr=1.00,
        allowed_gpu_types=["RTX_4090", "A6000", "A100_PCIE_40GB"],
        max_instances=5,
        spot_only=False,
    ),
    "production": VastAIConfig(
        api_key=os.environ.get("VAST_API_KEY_PROD", ""),
        max_price_per_hr=4.00,    # up to H100 range
        allowed_gpu_types=["A100_SXM4_80GB", "H100_SXM5_80GB", "A100_PCIE_40GB"],
        max_instances=20,
        spot_only=False,
    ),
}

def get_vastai_config() -> VastAIConfig:
    env = os.environ.get("APP_ENV", "development")
    config = ENV_CONFIGS.get(env, ENV_CONFIGS["development"])
    if not config.api_key:
        raise ValueError(f"VAST_API_KEY not configured for {env}")
    return config

Step 3: Policy-Enforced Instance Creation

# lib/vastai_service.py
import vastai
from config.vastai import get_vastai_config

def find_cheapest_valid_instance(gpu_count: int = 1):
    """Find cheapest instance matching environment policy."""
    cfg = get_vastai_config()
    vastai.api_key = cfg.api_key

    # Build search query respecting environment policy
    gpu_filter = " || ".join(f"gpu_name={g}" for g in cfg.allowed_gpu_types)
    query = f"({gpu_filter}) num_gpus={gpu_count} dph_total<{cfg.max_price_per_hr}"

    if cfg.spot_only:
        query += " reliability>0.9"  # spot instances with high reliability

    offers = vastai.search_offers(query, order="dph_total", limit=5)

    if not offers:
        raise ValueError(f"No instances matching policy under ${cfg.max_price_per_hr}/hr")

    return offers[0]

Step 4: Environment Variable Setup

# .env.local (development)
VAST_API_KEY=dev_key_abc123
APP_ENV=development

# GitHub Actions staging
VAST_API_KEY_STAGING=staging_key_def456
APP_ENV=staging

# GitHub Actions production
VAST_API_KEY_PROD=prod_key_xyz789
APP_ENV=production

Step 5: Startup Validation

# scripts/validate-vastai-env.py
from config.vastai import get_vastai_config

cfg = get_vastai_config()
print(f"Environment: {os.environ.get('APP_ENV', 'development')}")
print(f"Max price/hr: ${cfg.max_price_per_hr}")
print(f"Allowed GPUs: {', '.join(cfg.allowed_gpu_types)}")
print(f"Max instances: {cfg.max_instances}")
print(f"Spot only: {cfg.spot_only}")

# Verify key is valid
import vastai
vastai.api_key = cfg.api_key