Vastai Multi Env Setup

Vast.ai Multi-Environment Setup

Overview

Vast.ai "environments" for GPU workloads map to separate API keys with different spending limits, allowed GPU types, and maximum instance counts. Development experiments should be restricted to cost-efficient spot instances with low spending caps.

Prerequisites

• Vast.ai account with API key from cloud.vast.ai
• vastai CLI installed (pip install vastai)
• Different API keys or spending limits configured per team/environment

Environment Strategy

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
try:
    vastai.whoami()
    print("API key: VALID")
except Exception as e:
    print(f"API key: INVALID - {e}")

Error Handling

Examples

Quick Environment Validation

APP_ENV=production python3 scripts/validate-vastai-env.py

Find Cheapest Dev Instance

# Development: find RTX 3090 under $0.40/hr
vastai search offers 'gpu_name=RTX_3090 num_gpus=1 dph_total<0.40' --order dph_total --limit 3

Resources

• Vast.ai API Documentation
• Vast.ai CLI Reference
• Vast.ai Python API

Next Steps

For enterprise access control, see vastai-enterprise-rbac.

Output

• Configuration files or code changes applied to the project
• Validation report confirming correct implementation
• Summary of changes made and their rationale