Feature. Add metrics

Author: nskondratev

README.md

@@ -1,57 +1,77 @@
 # tg-bot-template
+
 Template repo with boilerplate code to write [Telegram bots in](https://core.telegram.org/bots/api) Go.
 
 ## What is this repo for?
-I implemented several bots for Telegram and each time I started by writing/copying boilerplate code.
-This repository is a template for a quick start of a new bot. It solves the following problems:
+
+I implemented several bots for Telegram and each time I started by writing/copying boilerplate code. This repository is
+a template for a quick start of a new bot. It solves the following problems:
+
 - App structure: follows the [Standard Go Project Layout](https://github.com/golang-standards/project-layout).
 - Handy middlewares for HTTP-like processing updates from Telegram.
-- Deploying bot as a [Google Cloud Function](https://cloud.google.com/functions) and convenient local debugging with polling updates.
+- Deploying bot as a [Google Cloud Function](https://cloud.google.com/functions) and convenient local debugging with
+  polling updates.
 - Structured logging with [zerolog](https://github.com/rs/zerolog) lib.
+- Sending custom metrics with [OpenCensus](https://opencensus.io/) to Google Cloud. See more
+  in [docs](https://cloud.google.com/monitoring/custom-metrics/open-census?hl=en).
 
 In short, this template will save you a couple of hours and allow you to immediately start implementing the bot's logic.
 
 ## Quickstart
-1. Press "Use this template" button at the top or just follow [the link](https://github.com/nskondratev/tg-bot-template/generate).
+
+1. Press "Use this template" button at the top or just
+   follow [the link](https://github.com/nskondratev/tg-bot-template/generate).
 2. Clone the generated repository to your machine.
-3. Rename module and change import paths by calling the command (replace `github.com/author/newbot` with yours repo name):
+3. Rename module and change import paths by calling the command (replace `github.com/author/newbot` with yours repo
+   name):
+
 ```bash
 ./scripts/rename.sh github.com/author/newbot
 ```
+
 4. Fill configuration in .env file:
+
 ```bash
 mv .env.example .env && nano .env
 ```
+
 5. Run your bot locally:
+
 ```bash
 make run
 ```
 
 To set up a webhook for receiving updates, fill the config in `.env` file and run the following command:
+
 ```bash
 ./scripts/set_webhook.sh
 ```
 
 To clear a webhook run the same script with `-c` flag provided:
+
 ```bash
 ./scripts/set_webhook.sh -c
 ```
 
 ## Next steps
+
 * Add domain-specific logic in [internal/app](./internal/app) package.
 * Add update handlers in [internal/app/bot/handlers](./internal/app/bot/handlers) package.
-* The library [telegram-bot-api](https://github.com/go-telegram-bot-api/telegram-bot-api) is used to work with Telegram Bot API.
+* The library [telegram-bot-api](https://github.com/go-telegram-bot-api/telegram-bot-api) is used to work with Telegram
+  Bot API.
 
 ## Project structure
+
 * `bin` - dir for compiled binary deps (look at the `tools` directory).
 * `cmd/bot` - entry-point for running bot locally.
 * `internal`:
-  * `internal/app` - contains business-logic layer and adapters to external world in sub-packages.
-  * `internal/bot` - wrappers to work with Telegram Bot API and middlewares implementation.
-  * `internal/bot/handlers` - handlers for different update types.
-  * `internal/bot/middleware` - middlewares for all updates.
-  * `internal/boot` - bootstrapping code for bot creation (used in local entry-point and Google Cloud Function).
-  * `internal/env` - utilities for getting env-vars values.
-  * `internal/logger` - logger creation code and custom log fields constants.
+    * `internal/app` - contains business-logic layer and adapters to external world in sub-packages.
+    * `internal/bot` - wrappers to work with Telegram Bot API and middlewares implementation.
+    * `internal/bot/handlers` - handlers for different update types.
+    * `internal/bot/middleware` - middlewares for all updates.
+    * `internal/boot` - bootstrapping code for bot creation (used in local entry-point and Google Cloud Function).
+    * `internal/env` - utilities for getting env-vars values.
+    * `internal/logger` - logger creation code and custom log fields constants.
+    * `internal/metrics` - metrics client creation code and registering of custom metrics.
 * `scripts` - handy scripts for renaming module, changing import paths and setting up webhook URL.
 * `tools` - binary deps of a project.

cmd/bot/main.go

@@ -13,6 +13,7 @@ import (
 	"github.com/nskondratev/tg-bot-template/internal/boot"
 	"github.com/nskondratev/tg-bot-template/internal/env"
 	"github.com/nskondratev/tg-bot-template/internal/logger"
+	"github.com/nskondratev/tg-bot-template/internal/metrics"
 )
 
 func main() {
@@ -22,7 +23,7 @@ func main() {
 
 	ctx, cancel := context.WithCancel(context.Background())
 
-	b, err := boot.InitBot(ctx, log)
+	b, err := boot.InitBot(ctx, log, &metrics.Client{})
 	if err != nil {
 		log.Fatal().Err(err).Msg("failed to init bot")
 	}

function.go

@@ -11,6 +11,7 @@ import (
 	"github.com/nskondratev/tg-bot-template/internal/boot"
 	"github.com/nskondratev/tg-bot-template/internal/env"
 	"github.com/nskondratev/tg-bot-template/internal/logger"
+	"github.com/nskondratev/tg-bot-template/internal/metrics"
 )
 
 var (
@@ -21,9 +22,16 @@ var (
 func init() {
 	var err error
 
+	ctx := context.Background()
+
 	log = logger.Must(env.String("LOG_LEVEL", "debug"), os.Stdout)
 
-	b, err = boot.InitBot(context.Background(), log)
+	stats, err := metrics.New(ctx)
+	if err != nil {
+		panic("failed to create metrics client: " + err.Error())
+	}
+
+	b, err = boot.InitBot(ctx, log, stats)
 	if err != nil {
 		panic("failed to init bot: " + err.Error())
 	}

go.mod

@@ -3,9 +3,11 @@ module github.com/nskondratev/tg-bot-template
 go 1.15
 
 require (
+	contrib.go.opencensus.io/exporter/stackdriver v0.13.4
 	github.com/go-telegram-bot-api/telegram-bot-api v1.0.1-0.20201107014523-54104a08f947
 	github.com/joho/godotenv v1.3.0
 	github.com/rs/zerolog v1.20.0
 	github.com/stretchr/testify v1.6.1
-	golang.org/x/sync v0.0.0-20190423024810-112230192c58
+	go.opencensus.io v0.22.5
+	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e
 )