slack-channel-configuration.ts

import * as iam from '@aws-cdk/aws-iam';
import * as sns from '@aws-cdk/aws-sns';
import * as cdk from '@aws-cdk/core';
import { CfnSlackChannelConfiguration } from './chatbot.generated';

/**
 * Properties for a new Slack channel configuration
 */
export interface SlackChannelConfigurationProps {

  /**
   * The name of Slack channel configuration
   */
  readonly slackChannelConfigurationName: string;

  /**
   * The permission role of Slack channel configuration
   *
   * @default - A role will be created.
   */
  readonly role?: iam.IRole;

  /**
   * The ID of the Slack workspace authorized with AWS Chatbot.
   *
   * To get the workspace ID, you must perform the initial authorization flow with Slack in the AWS Chatbot console.
   * Then you can copy and paste the workspace ID from the console.
   * For more details, see steps 1-4 in Setting Up AWS Chatbot with Slack in the AWS Chatbot User Guide.
   * @see https://docs.aws.amazon.com/chatbot/latest/adminguide/setting-up.html#Setup_intro
   */
  readonly slackWorkspaceId: string;

  /**
   * The ID of the Slack channel.
   *
   * To get the ID, open Slack, right click on the channel name in the left pane, then choose Copy Link.
   * The channel ID is the 9-character string at the end of the URL. For example, ABCBBLZZZ.
   */
  readonly slackChannelId: string;

  /**
   * The SNS topics that deliver notifications to AWS Chatbot.
   *
   * @default None
   */
  readonly notificationTopics?: sns.ITopic[];

  /**
   * Specifies the logging level for this configuration.
   * This property affects the log entries pushed to Amazon CloudWatch Logs.
   *
   * @default LoggingLevel.NONE
   */
  readonly loggingLevel?: LoggingLevel;
}

/**
 * Logging levels include ERROR, INFO, or NONE.
 */
export enum LoggingLevel {
  /**
   * ERROR
   */
  ERROR = 'ERROR',

  /**
   * INFO
   */
  INFO = 'INFO',

  /**
   * NONE
   */
  NONE = 'NONE',
}

/**
 * Represents a Slack channel configuration
 */
export interface ISlackChannelConfiguration extends cdk.IResource, iam.IGrantable {

  /**
   * The ARN of the Slack channel configuration
   * In the form of arn:aws:chatbot:{region}:{account}:chat-configuration/slack-channel/{slackChannelName}
   * @attribute
   */
  readonly slackChannelConfigurationArn: string;

  /**
   * The name of Slack channel configuration
   * @attribute
   */
  readonly slackChannelConfigurationName: string;

  /**
   * The permission role of Slack channel configuration
   * @attribute
   *
   * @default - A role will be created.
   */
  readonly role?: iam.IRole;

  /**
   * Adds a statement to the IAM role.
   */
  addToRolePolicy(statement: iam.PolicyStatement): void;
}

/**
 * Either a new or imported Slack channel configuration
 */
abstract class SlackChannelConfigurationBase extends cdk.Resource implements ISlackChannelConfiguration {
  abstract readonly slackChannelConfigurationArn: string;

  abstract readonly slackChannelConfigurationName: string;

  abstract readonly grantPrincipal: iam.IPrincipal;

  abstract readonly role?: iam.IRole;

  /**
   * Adds extra permission to iam-role of Slack channel configuration
   * @param statement
   */
  public addToRolePolicy(statement: iam.PolicyStatement): void {
    if (!this.role) {
      return;
    }

    this.role.addToPrincipalPolicy(statement);
  }
}

/**
 * A new Slack channel configuration
 */
export class SlackChannelConfiguration extends SlackChannelConfigurationBase {

  /**
   * Import an existing Slack channel configuration provided an ARN
   * @param scope The parent creating construct
   * @param id The construct's name
   * @param slackChannelConfigurationArn configuration ARN (i.e. arn:aws:chatbot::1234567890:chat-configuration/slack-channel/my-slack)
   *
   * @returns a reference to the existing Slack channel configuration
   */
  public static fromSlackChannelConfigurationArn(scope: cdk.Construct, id: string, slackChannelConfigurationArn: string): ISlackChannelConfiguration {
    const re = /^slack-channel\//;
    const resourceName = cdk.Stack.of(scope).parseArn(slackChannelConfigurationArn).resourceName as string;

    if (!re.test(resourceName)) {
      throw new Error('The ARN of a Slack integration must be in the form: arn:aws:chatbot:{region}:{account}:chat-configuration/slack-channel/{slackChannelName}');
    }

    class Import extends SlackChannelConfigurationBase {

      /**
       * @attribute
       */
      readonly slackChannelConfigurationArn = slackChannelConfigurationArn;
      readonly role?: iam.IRole = undefined;
      readonly grantPrincipal: iam.IPrincipal;

      /**
       * Returns a name of Slack channel configuration
       *
       * NOTE:
       * For example: arn:aws:chatbot::1234567890:chat-configuration/slack-channel/my-slack
       * The ArnComponents API will return `slack-channel/my-slack`
       * It need to handle that to gets a correct name.`my-slack`
       */
      readonly slackChannelConfigurationName = resourceName.substring('slack-channel/'.length);

      constructor(s: cdk.Construct, i: string) {
        super(s, i);
        this.grantPrincipal = new iam.UnknownPrincipal({ resource: this });
      }
    }

    return new Import(scope, id);
  }

  readonly slackChannelConfigurationArn: string;

  readonly slackChannelConfigurationName: string;

  readonly role?: iam.IRole;

  readonly grantPrincipal: iam.IPrincipal;

  constructor(scope: cdk.Construct, id: string, props: SlackChannelConfigurationProps) {
    super(scope, id, {
      physicalName: props.slackChannelConfigurationName,
    });

    this.role = props.role || new iam.Role(this, 'ConfigurationRole', {
      assumedBy: new iam.ServicePrincipal('chatbot.amazonaws.com'),
    });

    this.grantPrincipal = this.role;

    const configuration = new CfnSlackChannelConfiguration(this, 'Resource', {
      configurationName: props.slackChannelConfigurationName,
      iamRoleArn: this.role.roleArn,
      slackWorkspaceId: props.slackWorkspaceId,
      slackChannelId: props.slackChannelId,
      snsTopicArns: props.notificationTopics?.map(topic => topic.topicArn),
      loggingLevel: props.loggingLevel?.toString(),
    });

    this.slackChannelConfigurationArn = configuration.ref;
    this.slackChannelConfigurationName = props.slackChannelConfigurationName;
  }
}