[aws-chatbot] L2 support for SlackChannelConfiguration

[luckily]

Currently there's only L1 resources in CfnSlackChannelConfiguration of aws-chatbot.
Let's create L2 construct support.

Use Case And Proposed Solution

It's just like we create slack channel configuration via AWS web console.
There is pseudocode as below:

const slackChannel = new chatbot.SlackChannelConfiguration(this, 'MySlackChannel', {
  slackChannelConfigurationName: 'test-channel',
  slackWorkspaceId: 'YOUR_WORKSPACE_ID',
  slackChannelId: 'YOUR_CHANNEL_ID', 
});

slackChannel.addLambdaInvokeCommandPermissions();
slackChannel.addNotificationPermissions();
slackChannel.addSupportCommandPermissions();
slackChannel.addReadOnlyCommandPermissions();

slackChannel.addToPrincipalPolicy(new iam.PolicyStatement({
  effect: iam.Effect.ALLOW,
  actions: [
    's3:GetObject',
  ],
  resources: ['arn:aws:s3:::abc/xyz/123.txt'],
}));

Other

Associate with #5020

cc @skinny85

• 👋 I may be able to implement this feature request
• ⚠️ This feature might incur a breaking change

---

This is a 🚀 Feature Request

[humanzz]

Hey @luckily, it's great that you're looking into this because between @Stacy-D and myself, we too were keen to get an L2 construct very similar to what you proposed above in #8636 (comment).

Just to avoid duplication of efforts, I wanted to connect to know if you're planning to progress this soon with a contribution? Our initial plan was to try to do that sometime over next week but if you're going to be doing that we'd happily step back and await for your contribution :)

[luckily]

Hi @humanzz, I'm so happy that you have similar problem.

I have some plans to resolve this issue and this is my proposed.

These include:

1. L2 construct for CfnSlackChannelConfiguration of chatbot package.
2. L2 construct for CfnNotificationRule of codestarnotification package.
3. addNotification({...}) method of codebuild and codepipeline depend on above implements.

See also: #9680 #9682

[humanzz]

@luckily Thanks for acting super quickly on this... we can't wait till this gets merged/released :)

[skinny85]

@humanzz if you want to add your review to #9702 (is it similar to your own solution?).

[humanzz]

It’s quite similar; I added a couple of comments. Pinging @Stacy-D as she was the one actually working on our version if she has any additional comments