config.ts

/**
 * This function tries to fetch an environment variable with the given name.
 * If it doesn't exist, it exits the application.
 *
 * @author Soni
 *
 * @param name The name of the environment variable to fetch
 * @returns The value of the environment variable if it exists
 */
function requireEnv (name: string): string {
    // Stop process if the environment variable isn't present
    if (!process.env[name]) {
        console.error(`Required environment variable ${name} not present, exiting...`);
        process.exit(1);
    }
    return process.env[name];
}

/**
 * This object holds the global configuration of Epochtal that all parts of the application read from.
 * When Epochtal is started, this configuration is populated with data inherited from environment variables.
 * If parts of the configuration are not available as environment variables,
 * it will be populated with predefined default values where possible.
 *
 * @author Soni
 */
export const CONFIG: object = {
    /**
     * External API keys used by Epochtal
     */
    API_KEY: {
        /**
         * Steam API key
         */
        STEAM: requireEnv("STEAM_API_KEY"),
        /**
         * Discord API key
         */
        DISCORD: requireEnv("DISCORD_API_KEY")
    },
    /**
     * Internal secrets
     */
    SECRET: {
        /**
         * JWT (cookie) data encoding secret
         */
        JWT: requireEnv("JWT_SECRET"),
        /**
         * Internal request authentication secret
         */
        INTERNAL: requireEnv("INTERNAL_SECRET")
    },
    /**
     * The filesystem directories in which non-volatile data is stored
     */
    DIR: {
        /**
         * The directory to store runtime data in.
         * This includes user data, run data, category data, etc.
         */
        DATA: process.env.DATA_DIR ?? `${__dirname}/data`,
        /**
         * The directory to store binary dependencies in.
         * Epochtal will look for its dependencies in this directory.
         */
        BIN: process.env.BIN_DIR ?? `${__dirname}/bin`,
        /**
         * The directory to store runtime secrets in.
         * This includes curation weights and TLS keys.
         */
        SECRETS: process.env.SECRETS_DIR ?? `${__dirname}/secrets`
    },
    /**
     * The web URL of this deployed instance, including hostname and port, excluding protocol.
     * This is used to populate redirect URLs.
     *
     * NOTE: If running in a containerized manner,
     * make sure the port specified here is the publicly exposed port for the service.
     */
    WEB_URL: process.env.WEB_URL ?? "localhost:8080",
    /**
     * The port to run the Epochtal webserver on.
     */
    PORT: process.env.PORT ?? 8080,
    /**
     * Whether to host the webserver with TLS enabled.
     * If enabled, certificates need to be provided as `fullchain.pem` and `privkey.pem` in the SECRETS_DIR directory.
     */
    USE_TLS: process.env.USE_TLS === "true",
    /**
     * Whether clients are expected to connect to the exposed website with "https://"
     * (whether redirect URLs should be written with HTTPS instead of HTTP).
     * This will likely be the same as USE_TLS unless this deployment is exposed through a reverse proxy that terminates TLS.
     */
    USE_HTTPS: process.env.USE_HTTPS === "true",
    /**
     * The Discord channels used for this deployment
     */
    DISCORD_CHANNEL: {
        /**
         * The channel ID of the Discord announcement channel
         */
        ANNOUNCEMENTS: requireEnv("DISCORD_CHANNEL_ANNOUNCE"),
        /**
         * The channel ID of the Discord report channel
         */
        REPORTS: requireEnv("DISCORD_CHANNEL_REPORT"),
        /**
         * The channel ID of the Discord update channel
         */
        UPDATES: requireEnv("DISCORD_CHANNEL_UPDATE")
    },
    /**
     * The time span for the curation algorithm to curate for, in seconds.
     * This defines how far back in time the curation algorithm fetches maps from.
     */
    CURATE_SECONDS: process.env.CURATE_SECONDS ?? 604800 // Defaults to one week
};