Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

Configuration

For both local development and deployment, the configuration of the GCN web application is controlled by the environment variables. You can adjust the environment variables in any one of three ways:

  • .env file: Create a file called .env in the base directory of your project formatted like this:

    FOO=value_of_foo_for_local_testing
    BAR=value_of_bar_for_local_testing
    
  • preferences.arc file: Create a file called .preferences.arc in the base directory of your project formatted like this:

    @env
    testing
      FOO=value_of_foo_for_local_testing
      BAR=value_of_bar_for_local_testing
    
    production
      FOO=value_of_foo_for_deployment
      BAR=value_of_bar_for_deployment
    
  • arc env command: Adjust settings for production by running the following commands.

    npx arc env -e production --add FOO value_of_foo_for_deployment
    npx arc env -e production --add BAR value_of_bar_for_deployment
    

Supported environment variables

All environment variables are optional in local development. All environment variables with the exception of GCN_FEATURES are required in production deployment.

Important note about distinct API keys

Every API token documented below should have a distinct value for each deployment stage, beacuse:

  • it minimizes the security impact of a compromise of the token in one stage, and
  • it prevents rate limiting in one deployment stage from impacting other deployment stages.

For Astrophysics Data Service (ADS)

ADS only permits a single API token per registered email address. You can use subaddressing (also called plus addressing) to create separate ADS accounts.

For example, if your personal ADS account is registered to nancy.roman@nasa.gov, then you can create a separate ADS account for GCN production by registering the email address nancy.roman+gcn-prod@nasa.gov.

KeyDescriptionDefault
SESSION_SECRET

Signing key for session cookies. Should be a long, random string

Hard-coded constant
CDN_SECRET

Secret key that must be present in the X-CDN-Secret request header of all requests to prove that the request came via the content delivery network rather than directly to the origin. Should be a long, random string

Requests are permitted regardless of the value of the X-CDN-Secret header

COGNITO_USER_POOL_ID, OIDC_CLIENT_ID, OIDC_CLIENT_SECRET

OpenID Connect identity provider configuration for AWS Cognito

Sandbox identity provider
RECAPTCHA_SITE_KEY, RECAPTCHA_SECRET_KEY

Google ReCAPTCHA configuration

ReCAPTCHAs replaced with placeholder
GITHUB_API_TOKEN

GitHub API token for the schema browser. In GitHub settings, generate a Classic token with the expiration as long as possible and no scopes selected

Anonymous GitHub API requests with lower rate limits
ORIGIN

URL origin for external redirects, email From addresses, etc.

http://localhost:3333
ZENDESK_EMAIL

Email address for Zendesk forwarding

Forwarding disabled
ZENDESK_TOKEN, ZENDESK_TOKEN_EMAILZendesk API token and user email addressZendesk API disabled
ADS_TOKEN

Astrophysics Data System (ADS) API token

ADS disabled
ADS_TOKEN_TOOLTIP

ADS API token used for Astro Flavored Markdown tooltips. The value must be different from ADS_TOKEN

ADS disabled
GCN_FEATURES

Feature flags (for example, ANTIGRAVITY,TIME_TRAVEL,PYROKINESIS)

No features
TNS_BOT_NAME, TNS_BOT_KEY, TNS_BOT_ID

Bot credentials for Transient Name Server (TNS)

TNS tooltips disabled
Looking for U.S. government information and services? Visit USA.gov