@netlify/build/lib/utils/environment.js

Netlify build module

// This is not the final source of truth about which environment variable keys are reserved and
// which are not; the Netlify API will ultimately reject illegal environment variables when creating
// a deploy. We do local validation to let a user or plugin developer know as soon as is possible
// that an injected environment variable will later fail the build.
const RESERVED_ENV_VAR_KEYS = new Set([
    // AWS-specific env vars
    'AWS_REGION',
    'AWS_EXECUTION_ENV',
    'AWS_LAMBDA_FUNCTION_NAME',
    'AWS_LAMBDA_FUNCTION_MEMORY_SIZE',
    'AWS_LAMBDA_FUNCTION_VERSION',
    'AWS_LAMBDA_LOG_GROUP_NAME',
    'AWS_LAMBDA_LOG_STREAM_NAME',
    'AWS_ACCESS_KEY_ID',
    'AWS_SECRET_ACCESS_KEY',
    'AWS_SESSION_TOKEN',
    'AWS_LAMBDA_RUNTIME_API',
    // Build metadata https://docs.netlify.com/configure-builds/environment-variables/#build-metadata
    'NETLIFY',
    'BUILD_ID',
    'CONTEXT',
    // Git metadata https://docs.netlify.com/configure-builds/environment-variables/#git-metadata
    'REPOSITORY_URL',
    'BRANCH',
    'HEAD',
    'COMMIT_REF',
    'CACHED_COMMIT_REF',
    'PULL_REQUEST',
    'REVIEW_ID',
    // Deploy URLs and metadata// https://docs.netlify.com/configure-builds/environment-variables/#deploy-urls-and-metadata
    'URL',
    'DEPLOY_URL',
    'DEPLOY_PRIME_URL',
    'DEPLOY_ID',
    'SITE_NAME',
    'SITE_ID',
    'NETLIFY_IMAGES_CDN_DOMAIN',
    'INCOMING_HOOK_TITLE',
    'INCOMING_HOOK_URL',
    'INCOMING_HOOK_BODY',
]);
export const isReservedEnvironmentVariableKey = (key) => RESERVED_ENV_VAR_KEYS.has(key);