ASAB Iris

Welcome to ASAB Iris, your go-to multifunctional messenger microservice, designed for automated document rendering and message dispatching across various communication channels!

Use Cases

📧 1. Sending Emails

Overview

• Craft beautiful emails with templates using Jinja, Markdown, or HTML.
• Personalize recipient details or go with default configurations.
• Trigger them through a web handler or an Apache Kafka message - flexibility is key!

Configuration

[smtp]
host=smtp.example.com
user=admin
password=secret
from=info@example.com
ssl=no
starttls=yes
subject=Mail from ASAB Iris

Explanation

• host: Your SMTP server's address.
• user: Your username for the SMTP server.
• password: Your super-secret password.
• from: The default "From" address for your emails.
• ssl: yes/no for SSL, depends on the SMTP server.
• starttls: yes/no for STARTTLS, depends on the SMTP server.
• subject: The default subject line, if not provided by a caller or a template.

Email Markdown Wrapper Configuration

Configuration

[email]
markdown_wrapper=/Templates/Email/body_wrapper.html

• markdown_wrapper: Specifies the path to the HTML template for wrapping email content. If this configuration is not provided, or if the value is left empty, the markdown_wrapper will default to None. In such cases, Markdown-formatted emails will be sent without any additional HTML wrapping. This means the emails will consist solely of the content converted from Markdown to HTML, without any extra styling or structure provided by a wrapper template.

🚨 2. Sending Slack messages

Overview

• Send messages to a Slack via HTTP REST API or through Kafka Topic
• Apply Jinja2 templates.
• Trigger them through a web handler or an Apache Kafka message - flexibility is key!

Configuration

[slack]
token=xoxb-111111111111-2222222222222-3333333333333voe
channel=general

Explanation

• token: Your Slack OAuth access token.
• channel: The Slack channel you want to send messages to.

🤖 Creating Slack OAuth access token for Slack Apps

Prerequisites

• A Slack workspace where you're the admin of app creation.

Steps

1. Visit the Slack API website.
2. Select "Create New App".
3. Name your app and choose its home (workspace).
4. Select "Create App"
5. Configure "OAuth & Permissions".
6. Add the necessary scopes: chat:write, files:write, files:read and channels:read.
7. Select "Install to Workspace".
8. "Allow"
9. Copy the OAuth access token.

Add following scopes for:

• groups:read: for posting to private channels
• im:read: for posting to direct messsages
• mpim:read: for posting to group direct messages

Adding the App to a Channel

1. Choose a channel in your Slack workspace.
2. Invite the app.
3. Search for your app and select it.
4. Confirm the addition.
5. Verify the app's presence.

📬 3. Sending Microsoft Teams messages

Overview

• Send messages to a Microsoft Teams via HTTP REST API or thru Kafka Topic
• Apply Jinja2 templates.
• Trigger them through a web handler or an Apache Kafka message - flexibility is key!

Configuration

[outlook]
webhook_url=https://outlook.office.com/webhook/...

Explanation

• webhook_url: Your webhook URL.

Error Handling

asab-iris implements specific error handling strategies for the Kafka and Web handlers to ensure robustness and reliability.

KafkaHandler Error Handling

• Fallback Mechanism: In case of errors during message processing, a fallback mechanism is triggered. This ensures that the system can still operate or recover gracefully when encountering issues.
• General Error Logging: Any errors during message dispatching are logged as exceptions.

WebHandler Error Handling

• Error Responses: Internal error codes are mapped to HTTP status codes, providing meaningful responses to clients.
• Exception Handling: General exceptions are logged, and standardized error responses are sent to clients.

📱 4. Sending SMS messages

Overview

• Send SMS messages using the SMSBrana.cz API.
• Supports automatic segmentation of long messages.
• Apply Jinja2 templates.
• Trigger them through a web handler or an Apache Kafka message - flexibility is key!

Configuration

[sms]
login=your_smsbrana_login
password=your_smsbrana_password
timestamp_format=%Y%m%dT%H%M%S
api_url=https://api.smsbrana.cz/smsconnect/http.php

Explanation

• login: Your login for the SMSBrana.cz service.
• password: Your password for the SMSBrana.cz service.
• timestamp_format: The format used for timestamps, typically "%Y%m%dT%H%M%S".
• api_url: The API URL for SMSBrana.cz, typically https://api.smsbrana.cz/smsconnect/http.php.

Handling Long Messages

• SMS messages are automatically split into segments if they exceed the length limits:
  • 1 SMS: up to 160 characters.
  • 2 SMS: up to 306 characters (153 characters per segment).
  • 3 SMS: up to 459 characters (153 characters per segment).
• Each segment is sent separately, ensuring that messages are not truncated.

Usage Example

To send an SMS, you can configure the SMS service in your application and trigger it via a web handler or Kafka message. The service will handle splitting long messages into segments and sending them sequentially.

Error Handling

• Invalid Phone Number: If the phone number is missing or invalid, an ASABIrisError is raised.
• Non-ASCII Characters: If the message contains non-ASCII characters, an ASABIrisError is raised.
• Service Errors: Errors returned by the SMSBrana.cz API are mapped to custom error messages and logged for troubleshooting.

🛠 Supported Technologies

• Inbound: HTTP REST API
• Inbound: Apache Kafka
• Jinja2 for template specifications
• Markdown for templates
• HTML for templates and the output
• PDF for the output
• Output: Email SMTP
• Output: Slack
• Output: Microsoft Teams
• Powered by ASAB (because we’re standing on the shoulders of giants)

📚 More info

• Documentation

Diagram: Architecture

Jinja2 Filters and Functions

now() Function

The now() function returns the current UTC datetime. You can use this function in your Jinja2 templates to insert the current date and time.

Usage Example:

{{ now() }}

This will output the current date and time in the default format.

datetimeformat Filter

The datetimeformat filter allows you to format datetime objects in your Jinja2 templates.

Usage Example:

To format the current datetime returned by now():

{{ now()|datetimeformat('%Y-%m-%d %H:%M:%S') }}

Possible Formats:

Here are some common format strings you can use with the datetimeformat filter:

• %Y-%m-%d %H:%M:%S - Outputs as 2024-06-17 14:45:30
• %d-%m-%Y - Outputs as 17-06-2024
• %A, %d %B %Y - Outputs as Monday, 17 June 2024
• %I:%M %p - Outputs as 02:45 PM
• %B %d, %Y - Outputs as June 17, 2024
• %Y-%m-%d - Outputs as 2024-06-17

🚀 5. Sending Notifications to Kafka

Overview

ASAB Iris supports sending notifications to various communication channels such as email, Slack, and Microsoft Teams via Kafka. Each notification is structured using templates and parameters to ensure customizable content.

Kafka Message Structure

• Notifications are sent to Kafka in JSON format.
• Each notification contains a type field specifying the channel (e.g., email, slack, msteams), and a body that includes the template and its parameters.

1. Sending Email Notifications

Example Kafka Message:

{
    "type": "email",
    "to": ["Shivashankar <mithunshivashankar@gmail.com>"],
    "from": "info@teskalabs.com",
    "body": {
        "template": "/Templates/Email/message.md",
        "params": {
            "name": "I am testing a template",
            "error": "None"
        }
    }
}

Explanation:

• type: Defines the notification type as email.
• to: List of recipients.
• from: The sender's email address.
• template: Path to the template used for the email content.
• params: Parameters for populating the email template.

2. Sending Slack Notifications

Example Kafka Message:

{
    "type": "slack",
    "body": {
        "template": "/Templates/Slack/Slack example.md",
        "params": {
            "name": "I am testing a template",
            "error": "None"
        }
    }
}

Explanation:

• type: Defines the notification type as slack.
• body.template: Path to the Slack message template.
• params: Parameters for populating the Slack template.

3. Sending Microsoft Teams Notifications

Example Kafka Message:

{
    "type": "msteams",
    "body": {
        "template": "/Templates/MSTeams/Teams example.md",
        "params": {
            "name": "I am testing a template",
            "error": "None"
        }
    }
}

Explanation:

• type: Defines the notification type as msteams.
• body.template: Path to the Microsoft Teams message template.
• params: Parameters for populating the Teams template.