Secrets Management

Secrets Management Patterns

Environment Variables Best Practices

# .env — local dev only, NEVER commit
DATABASE_URL=postgresql://user:pass@localhost/mydb
JWT_SECRET=change-me-in-production

# .env.example — commit this (no real values)
DATABASE_URL=postgresql://user:password@localhost/dbname
JWT_SECRET=generate-with-openssl-rand-hex-32

# .gitignore
.env
.env.local
.env.*.local
*.pem
*_rsa
*_dsa
secrets/

# Validate required secrets at startup — fail fast
import os

REQUIRED_SECRETS = ["DATABASE_URL", "JWT_SECRET", "REDIS_URL", "STRIPE_KEY"]

def validate_secrets():
    missing = [s for s in REQUIRED_SECRETS if not os.environ.get(s)]
    if missing:
        raise RuntimeError(f"Missing required secrets: {', '.join(missing)}")

validate_secrets()  # called at module load

HashiCorp Vault

import hvac

client = hvac.Client(url="https://vault.internal:8200")

# AppRole authentication (for services)
client.auth.approle.login(
    role_id=os.environ["VAULT_ROLE_ID"],
    secret_id=os.environ["VAULT_SECRET_ID"]
)

# Read secret
secret = client.secrets.kv.v2.read_secret_version(
    path="myapp/database",
    mount_point="secret"
)
db_password = secret['data']['data']['password']

# Dynamic secrets — Vault generates short-lived DB credentials
db_creds = client.secrets.database.generate_credentials(name="myapp-role")
# db_creds['data']['username'], db_creds['data']['password']
# Automatically revoked after TTL (e.g., 1 hour)

# Token renewal
client.auth.token.renew_self()

AWS Secrets Manager

import boto3, json
from functools import lru_cache

secrets_client = boto3.client('secretsmanager', region_name='us-east-1')

@lru_cache(maxsize=None)
def get_secret(secret_name: str) -> dict:
    response = secrets_client.get_secret_value(SecretId=secret_name)
    return json.loads(response['SecretString'])

# Usage
db_config = get_secret("prod/myapp/database")
db_url = f"postgresql://{db_config['username']}:{db_config['password']}@{db_config['host']}/{db_config['dbname']}"

# Rotation — Lambda function triggered automatically
def rotate_secret(event, context):
    step = event['Step']
    secret_id = event['SecretId']
    token = event['ClientRequestToken']
    if step == 'createSecret':
        # Generate new credentials
        new_password = secrets.token_urlsafe(32)
        secrets_client.put_secret_value(
            SecretId=secret_id,
            ClientRequestToken=token,
            SecretString=json.dumps({**current, 'password': new_password}),
            VersionStages=['AWSPENDING']
        )
    elif step == 'testSecret':
        # Test AWSPENDING version
        pass
    elif step == 'finishSecret':
        secrets_client.update_secret_version_stage(...)

Docker / Kubernetes Secrets

# Kubernetes Secret
apiVersion: v1
kind: Secret
metadata:
  name: app-secrets
type: Opaque
stringData:
  database-url: postgresql://...
  jwt-secret: changeme

# Use in Pod
envFrom:
  - secretRef:
      name: app-secrets

# External Secrets Operator (sync from Vault/AWS SM)
apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: app-secrets
spec:
  refreshInterval: 1h
  secretStoreRef:
    name: vault-backend
    kind: ClusterSecretStore
  target:
    name: app-secrets
  data:
    - secretKey: database-url
      remoteRef:
        key: secret/myapp/database
        property: url

Secret Scanning

# Pre-commit hook with gitleaks
gitleaks protect --staged
# .gitleaks.toml to customize patterns

# truffleHog — scan git history
trufflehog git file://. --since-commit HEAD --only-verified

# GitHub secret scanning — enable in repository settings
# detect-secrets baseline
detect-secrets scan > .secrets.baseline
detect-secrets audit .secrets.baseline

# Pre-commit config
# - repo: https://github.com/Yelp/detect-secrets
#   hooks:
#     - id: detect-secrets
#       args: ['--baseline', '.secrets.baseline']

Rotation Checklist

• All secrets have defined rotation schedule
• Zero-downtime rotation: deploy new secret → update service → revoke old
• Rotation tested in staging before production
• Alerts on secret access from unexpected IPs/services
• Audit log enabled for all secret reads
• Emergency rotation procedure documented