chore(kb/slack): bots, bots everywhere

knowledge base/slack.md

@@ -3,8 +3,9 @@
 1. [TL;DR](#tldr)
 1. [Add custom emoji](#add-custom-emoji)
 1. [Give aliases to existing emojis](#give-aliases-to-existing-emojis)
-1. [Apps](#apps)
-1. [Incoming webhooks](#incoming-webhooks)
+1. [Use incoming webhooks for notifications](#use-incoming-webhooks-for-notifications)
+1. [Use bots for notifications](#use-bots-for-notifications)
+1. [Create apps](#create-apps)
 1. [Further readings](#further-readings)
    1. [Sources](#sources)
 
@@ -18,16 +19,38 @@ brew install --cask 'slack'
 mas install '803453959'
 ```
 
+CLI:
+
+```sh
+brew install --cask 'slack-cli' \
+&& slack login
+```
+
+Authorization data will be saved to `~/.slack/credentials.json`.
+
 </details>
 
 <details>
   <summary>Usage</summary>
 
 ```sh
-# Send notifications to channels
-curl -X 'POST' -H 'Content-type: application/json' \
-  --data '{"text": "Hello, World!"}' \
-  'https://hooks.slack.com/services/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'
+# Login.
+slack login
+
+# List authorized accounts.
+slack auth list
+slack list
+```
+
+```sh
+# Send notifications to channels using the APIs.
+curl --request 'POST' --url 'https://slack.com/api/chat.postMessage?pretty=1' \
+  --header 'Authorization: Bearer xoxb-012345678901-0123456789012-abcdefghijklmnopqrstuvwx' \
+  --header 'Content-type: application/json' --data '{"channel": "C04K1234567", "text": "Hello, World!"}'
+
+# Send notifications to channels using incoming webhooks.
+curl --request 'POST' --url 'https://hooks.slack.com/services/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' \
+  --header 'Content-type: application/json' --data '{"text": "Hello, World!"}'
 ```
 
 </details>
@@ -59,38 +82,62 @@ Check out [slackmojis] for some common reactions.
 1. Choose the image.
 1. Give it an alias.
 
-## Apps
-
-Direct links:
-
-- [Create a new App](https://api.slack.com/apps?new_app=1).
-
-## Incoming webhooks
+## Use incoming webhooks for notifications
 
 Refer [Sending messages using incoming webhooks] and [Setting Up Slack Webhook URL Simplified 101].
 
 1. Enable Incoming Webhooks for a Slack app.<br/>
    _Features_ → _Incoming Webhooks_ → _Activate Incoming Webhooks_.
 1. Create a new Webhook URL and authorize it (or request authorization for it).
-1. Install the app in the workspace.
-1. Send a test request to the webhook.
+1. Install (or request an higher entity to install) the app in the workspace.<br/>
+   App details → _Settings_ → _Install App_ → _OAuth Tokens_.<br/>
+1. Send a test request to the webhook:
 
    ```sh
-   curl -X 'POST' -H 'Content-type: application/json' \
-     'https://hooks.slack.com/services/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' --data '{"text": "Hello, World!"}'
+   curl --request 'POST' --url 'https://hooks.slack.com/services/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' \
+     --header 'Content-type: application/json' --data '{"text": "Hello, World!"}'
    ```
 
+## Use bots for notifications
+
+Refer [Automating Slack Notifications: Sending Messages as a Bot with Python].
+
+1. [Create a new Slack App][create apps].
+1. Select _From Scratch_.
+1. Enter a name (e.g., `test bot`) and select a workspace for it.
+1. Add the required OAuth scopes (e.g. `chat:write`).<br/>
+   App details → _Features_ → _OAuth & Permissions_ → _Scopes_ → _Bot Token Scopes_.
+1. Install (or request an higher entity to install) the app in the workspace.<br/>
+   App details → _Settings_ → _Install App_ → _OAuth Tokens_.<br/>
+   This will automatically generate an OAuth token for the app. Note that token down.
+1. Add the app to the channels it needs to interact with.
+   Channel details → _Integrations_ tab → _Apps_ section → _Add apps_.
+1. Try sending messages using the app's OAuth token:
+
+   ```sh
+   curl --request 'POST' --url 'https://slack.com/api/chat.postMessage?pretty=1' \
+     --header 'Authorization: Bearer xoxb-012345678901-0123456789012-abcdefghijklmnopqrstuvwx' \
+     --header 'Content-type: application/json' --data '{"channel": "C04K1234567", "text": "Hello, World!"}'
+   ```
+
+## Create apps
+
+[Direct link](https://api.slack.com/apps?new_app=1).
+
 ## Further readings
 
 - [Website]
 - [Sending messages using incoming webhooks]
 - [Posting messages using curl]
+- [CLI]
 
 ### Sources
 
 - [Slackmojis]
 - [Slack Notifications for Ansible Tower (AWX)]
 - [Setting Up Slack Webhook URL Simplified 101]
+- [How to quickly get and use a Slack API bot token]
+- [Automating Slack Notifications: Sending Messages as a Bot with Python]
 
 <!--
   Reference
@@ -98,14 +145,19 @@ Refer [Sending messages using incoming webhooks] and [Setting Up Slack Webhook U
   -->
 
 <!-- In-article sections -->
+[create apps]: #create-apps
+
 <!-- Knowledge base -->
 <!-- Files -->
 <!-- Upstream -->
+[cli]: https://tools.slack.dev/slack-cli/
 [posting messages using curl]: https://api.slack.com/tutorials/tracks/posting-messages-with-curl
 [sending messages using incoming webhooks]: https://api.slack.com/messaging/webhooks
 [website]: https://slack.com/
+[how to quickly get and use a slack api bot token]: https://api.slack.com/tutorials/tracks/getting-a-token
 
 <!-- Others -->
+[automating slack notifications: sending messages as a bot with python]: https://medium.com/@sid2631/automating-slack-notifications-sending-messages-as-a-bot-with-python-2beb6c16cd8c
 [setting up slack webhook url simplified 101]: https://hevodata.com/learn/slack-webhook-url/
 [slack notifications for ansible tower (awx)]: https://mpolinowski.github.io/docs/DevOps/Ansible/2021-04-30-ansible-tower-slack-notifications/2021-04-30/
 [slackmojis]: https://slackmojis.com/