A sample command-line application with an entrypoint in bin/, library code in lib/, and example unit test in test/.

New Cloud Functions Telegram bot project

Skeleton

1. Create a project
2. Add dependencies

dependencies:
    chatterbox: ^1.0.0
    functions_framework: ^0.4.0
    shelf: ^1.0.0
dev_dependencies:
  build_runner: 2.4.13
  functions_framework_builder: ^0.4.0

3. create lib/functions.dart

@CloudFunction()
Future<Response> function(Map<String, dynamic> updateJson) async {
  try {
    final flows = <Flow>[
      //todo
    ];

    Chatterbox(Config.botToken, flows, StoreProxy()).invokeFromWebhook(updateJson);
    return Response.ok(
      null,
      headers: {'Content-Type': 'application/json'},
    );
  } catch (error) {
    return Response.badRequest();
  }
}

4. Add config.dart

import 'dart:io';

class Config {
  Config._();

  static String get botName => env('BOT_NAME');

  static String get botToken => env('BOT_TOKEN');
}

T env<T>(String key) {
  final value = Platform.environment[key];
  if (value == null) {
    throw 'Missing $key environment variable';
  } else {
    print('$key: ${value.substring(0, 5)}');
    return value as T;
  }
}

5. Add Makefile

.PHONY: clean

FUNCTION_TARGET = function
PORT = 8080

# bin/server.dart is the generated target for lib/functions.dart
bin/server.dart:
	dart run build_runner build --delete-conflicting-outputs

build: bin/server.dart

test: clean build
	dart test

clean:
	dart run build_runner clean
	rm -rf bin/server.dart

run: build
	dart run bin/server.dart --port=$(PORT) --target=$(FUNCTION_TARGET)
	
gen_all:
	dart run build_runner build --delete-conflicting-outputs

Create Telegram Bot

1. Go to Telegram https://t.me/BotFather and create a new bot
2. Store env variables

BOT_NAME=portugoosse_bot;BOT_TOKEN=6574774245:AAG7ErwTd2Gol5Jrtu-_U9wuWVscWXaM500

Building

1. Run make gen_all
2. From another terminal run a test command

$ curl -X POST -H "content-type: application/json" -d '{ "name": "World" }' -i localhost:8080

You should see the response

HTTP/1.1 200 OK
x-powered-by: Dart with package:shelf
date: Thu, 26 Oct 2023 07:18:50 GMT
content-length: 0
x-frame-options: SAMEORIGIN
content-type: application/json
x-xss-protection: 1; mode=block
x-content-type-options: nosniff

Flows development

1. Start by creating a class that extends Flow

class StartFlow extends Flow {
  @override
  List<StepFactory> get steps => [
        () => _InitialStep(),
  ];
}

If you need your flow to be invoked by a command, like /start it should extend CommandFlow like this:

class StartFlow extends CommandFlow {
  @override
  String get command => "start";
}

2. Add Step

class _InitialStep extends FlowStep {
  @override
  Future<Reaction> handle(MessageContext messageContext, [List<String>? args]) async {
    return ReactionResponse(text: 'Hello, fren');
  }
}

3. Register Flow in flows array in main function

    final flows = <Flow>[
      StartFlow()
    ];

Testing bot end to end on local machine

1. Install (ngrok)[https://ngrok.com/]
2. Run it ngrok http 8080
3. Copy Forwarding url and set it as a webhook for your bot with a following url command with your BOT_TOKEN

curl --location 'https://api.telegram.org/bot{{BOT_TOKEN}}/setWebhook' \
--header 'Content-Type: application/json' \
--data '{
    "url": "{{FORWARDING_URL}}" 
}'

curl --location 'https://api.telegram.org/bot6574774245:AAG7ErwTd2Gol5Jrtu-_U9wuWVscWXaM500/setWebhook'
--header 'Content-Type: application/json'
--data '{ "url": "https://5ef6-86-94-11-222.ngrok.io" }' Notice bot prefix, before bot token.

Update to trigger deployment

Bootstraping

1. Upload your code to github

2. Create a new Google Cloud project

gcloud projects create project_name

2. Select current project

    gcloud config set project project_id

3. Setup Secret Manager for Cloud Build service

   • Setup Secret Manager API

     gcloud services enable secretmanager.googleapis.com

   • Grant secretmanager.secrets.create permission:

     gcloud projects add-iam-policy-binding jobstash-bot --member="serviceAccount:service-618164590307@gcp-sa-cloudbuild.iam.gserviceaccount.com" --role="roles/secretmanager.secretCreator"

4. Setup continuous deployment from source repository using Cloud Build

gcloud builds connections create github --region=your_region_of_choice 
gcloud builds connections create github https://github.com/Defuera/jobstash_bot.git --region=europe-west4


gcloud run regions list //to 

4. Download service account key to access firestore from local machine and place it into .keys/scf-service-account-key.json

 gcloud iam service-accounts keys create scf-service-account-key.json --iam-account=YOUR_SERVICE_ACCOUNT_EMAIL

Add an environment variable GOOGLE_APPLICATION_CREDENTIALS=.keys/scf-service-account-key.json

6. Add Firestore database to your project

firebase init

And then follow steps ? Please select an option: Add Firebase to an existing Google Cloud Platform project ? Select the Google Cloud Platform project you would like to add Firebase: jobstash-bot (jobstash-bot)