config.ts

import chalk from "chalk";
import convict from "convict";
import deepmerge from "deepmerge";
import prettyjson from "prettyjson";
import * as winston from "winston";
import { Argv } from "yargs";
import { Provider } from "./providers/provider";

export class Config {
  private static initialConfig = {
    verbose: {
      doc: "Logging everything or just the important stuff.",
      format: ["true", "false"],
      default: "false",
      env: "VERBOSE"
    },
    env: {
      doc: "The application environment.",
      format: ["production", "development", "test"],
      default: "development",
      env: "NODE_ENV"
    },
    projectPrefix: {
      doc:
        "A short project name which is used for directories on the SFTP server.",
      default: "",
      env: "PROJECT_PREFIX"
    },
    source: {
      type: {
        doc: "The type of service to back-up.",
        default: "",
        env: "SOURCE_TYPE"
      }
    },
    target: {
      host: {
        doc: "The target host.",
        default: "",
        env: "TARGET_HOST"
      },
      port: {
        doc: "The SFTP port",
        default: "22",
        env: "TARGET_PORT"
      },
      username: {
        doc: "The SFTP username",
        default: "",
        env: "TARGET_USERNAME"
      },
      password: {
        doc: "The SFTP password",
        default: "",
        env: "TARGET_PASSWORD",
        sensitive: true
      },
      maxBackups: {
        weekly: {
          doc: "Maximum number of backups to keep for weekly backups",
          default: "4",
          env: "TARGET_MAX_BACKUPS_WEEKLY"
        },
        daily: {
          doc: "Maximum number of backups to keep for daily backups",
          default: "6",
          env: "TARGET_MAX_BACKUPS_DAILY"
        }
      }
    },
    slack: {
      webhook: {
        doc: "The webhook URL.",
        default: "",
        env: "SLACK_WEBHOOK"
      }
    },
    cluster: {
      enabled: {
        doc:
          "Enable cluster-mode in which for multiple lifebelt processes only a single one (the leader) performs backups.",
        format: ["true", "false"],
        default: "false",
        env: "CLUSTER_ENABLED"
      },
      leaderUrl: {
        doc: "The URL with which to determine which process is the leader.",
        default: "http://localhost:4040/",
        env: "CLUSTER_LEADER_URL"
      }
    },
    cron: {
      weeklySchedule: {
        doc: "The time by which to start a weekly backup",
        default: "00 30 2 * * 0",
        env: "CRON_WEEKLY_SCHEDULE"
      },
      dailySchedule: {
        doc: "The time by which to start a daily backup",
        default: "00 30 2 * * 1-6",
        env: "CRON_DAILY_SCHEDULE"
      },
      delay: {
        doc:
          "The minutes by which to delay each backup execution. A random value between 0 and 120 is picked if empty (the default).",
        default: "",
        env: "CRON_DELAY"
      }
    }
  };
  private static schema: any = convict(Config.initialConfig);
  private static mandatoryKeys = [
    "projectPrefix",
    "source.type",
    "target.host",
    "target.username",
    "target.port"
  ];

  static get(key: string) {
    return this.schema.get(key);
  }

  static mergeProviderConfig(provider: Provider) {
    const verbose = this.schema.get("verbose");
    this.schema = convict(deepmerge(this.initialConfig, provider.config()));
    this.schema.set("verbose", verbose);
    provider.mandatoryKeys().forEach(k => this.mandatoryKeys.push(k));
    let error = false;
    this.mandatoryKeys.forEach(k => {
      if (this.schema.get(k) === "") {
        winston.error(
          `Config is missing ${chalk.underline("mandatory")} key %s`,
          chalk.bold(k)
        );
        error = true;
      }
    });

    if (error) {
      process.exit(1);
    }
  }

  static mergeYargs(argv: Argv) {
    if (argv["v"] !== undefined) {
      this.schema.set("verbose", argv["v"]);
    }
  }

  static print() {
    winston.debug(
      "Loaded the config:\n%s",
      prettyjson.render(JSON.parse(this.schema.toString()))
    );
  }
}